Volt meter drops 90 flhtcu
 

When my turn signal is working it causes my volt meter to drop drasticly, I don't have a flasher it is controlled through the module. Does anyone have any ideas?

That's typical for a degraded connection somewhere. Take off the fairing, with the engine off, turn everything on, headlight, turn signals, brake lights. Touch around the terminals on the breakers. Feel for a hot one. Follow the wires from the ignition switch. Warm wires is normal with all the lights on for a period of time. I had a hot terminal on one of my breakers that burnt my hand. If none stand out as being very hot, follow the wiring diagram for the bike and take off and clean every ring lug in the path from the battery thru the ignition switch. I usually end up doing that about every 2 or 3 years when I see my meter dipping.

Check the charging system Look at the stator plug as it comes through the left case Your charging system should put out 20 volts AC per thousand rpm to a max of 50 volts + or - at 2000 rpm Go to the bat when the bike is running the meter should read approx 13.5 volts DC Did you ever replace the stator or reg or did you buy the bike as is ?

All the above is correct and good info, but if all that checks out, I'd wager it's your ignition switch getting weak on the acc position. That is very common for that style switch, I've see many weak switches just like that.

While you have the dash off, run a jumper from the light breaker or ign breaker to the acc breaker. Turn everything on, hit the turn signal and if your gauge stops jumping bad - it's the switch.

While checking you hot wiring, check your grounds. Also I found a chafed wire under the fairing that had rubbed on the neck

Bubba

Just need to make sure I am clear because this is the exact problem I am having and it is driving me crazy! My left turn signal only works about 20% of the time and now the right one is starting to act up. My volt meter swings from about 12.75 down to under 10 when the turn signals are working and at idle it drops to 10 with just the brake light on. My ignition switch may have had some damage when it was repo'd years ago - before I bought it.

The "breaker" you are referring to is the row of little boxes under the fairing? And I just use my wiring diagram to find which one is the acc and which is ignition? I suspect a good cleaning of all contacts and some dielectric grease would be in order, right?

I hate electrical problems! I did replace stator and voltage regulator in May.

My volt meter drops down at idle with the brake on and has since new. I wouldn't worry too much about that. Yes, the breaker would be one of those boxes in a row. On my bike, and I'm gonna guess your's is the same, that would be the relay on the far left (patient's left), or on the right as you stand facing it. Unfortunately, this all relates to The Dreaded Click also.

Mine too. I never really worried much about it, as I was already used to seeing the same thing on an old Gold Wing I had.

The row of breakers, I assume are arranged the same on most FLs, but an easy check is with a test light or meter. You must have the switch in ACC only position to find it for certain.

You will have one that is always "hot" for the clock and radio memory. The ACC breaker supplies the brakes lights, turn signals, power to the start button, "line" power to the starter relay, horn, radio, oil/neutral lights and dash lights. That's why there is a drastic voltage drop when brakes are applied. And of course one breaker each, for the ignition and lights - which may be jumped together (from the factory)

A switch that's been tampered with, as in a repo operation is not the cause of failure, simply the contacts in the switch itself are wimpy and get tired after a long time. Those style switchs are obsolete/unavaliable and unservicable (can't take them apart like most HD switches)

When you find the ACC breaker, run a temporary wire from the battery to either side of the breaker and you'll see the volt gauge stay "up" when any of the functions are applied.

Assuming the switch checks out to be weak, it's really easy to add a relay under the seat to supply power to the ACC breaker by using the lead from the switch to trigger the relay. I don't have photos of mine, but if anyone needs more info on that modification let me know.

Mjunk1 - replace your turn signal flasher while you're messing with it too. Remember there are 2 and one runs the 4-ways, it's likely OK.
I had a similar problem for years and was replacing the wrong one cause I didn't know there were 2 - DUH...

t150 - thanks for the info - along with others. I'll go digging if I get some time tonight.

I have been toying with the idea of removing that ignition switch because my inner fairing was torn up a bit. Ithought if I could get rid of the switch I would just buy a new one and hide it somewhere else on the bike - then just make a plate to match my missing stereo and speakers to cover that area. Since it doesn't really lock anymore it is not very useful as a security device. I figured hiding the switch is actually a better move. Anyone know how hard it is to rip out that old switch and re-wire in a generic one?

The switch is about 1.75 in diameter and the same tall so you would have lots of room to play with under there. On the FLHs you have to remove the inner/outer farings to get to it all for total removal. On FLTs you only have to remove the dash and support housing (totally different fairing arrangement)

The only "trick" is getting the (lock) knob off. There is a pin/knob on the left side of the switch (under the housing) that you pull with needle noses. Push the knob down, pull the pin and lift the switch knob off. Then there will be a nut (like a radio antenna nut on a car) that screws off and it's free to come out.

The switch itself is simple as it gets. One hot going in, and 3 switched wires coming out. The ACC side is "hot" in all positions except off, the other 2 (ign and lights) are independent of each other. Any car or pickup switch for 50's -60's would work, but you'd only have acc and ign so you'd have to tie lights to ignition or run a seperate toggle for them. BUT, you could wire the starter to the switch. How cool would that be? :D

Help me out a little, by wiring the starter to the switch would i get a direct start by turning the switch - like a car - or would it be added security so that if someone didn't know where the switch was they wouldn't be able to start the bike?

I didn't get to take it apart last night but did go for a short ride. The turn signals worked fine when I first got going and all the way to the store about 10 miles away. Coming back I had intermittent use for the first few miles and then nothing. So whatever is going on gets worse as the bike heats up.

Yes, you could wire it like a car to start with the ignition switch rather than the button. Or you could wire it so the switch would have to be in the spring-loaded position before the start button would work, And you could wire it so you'd have ignition (and acc) on the acc position and lights plus ignition with the "on" position. Lots of options...

But one thing to consider, if your actual switch lock works, I'd do the relay thing for acc. (I'm forgetting all about the fork lock feature ever working) Also, if it won't lock the knob in the "lock" position, it's supposed to also lock the knob in the acc position. Might check that out for the heck of it. If that is something you'd live with, you'd tie the acc breaker to the ign and disconnect the acc wire from the switch alltogether.

Losing amperage/voltage when getting hot or after being under load, is one in the same so to speak - resistance causes heat, and heat incresases resistance. Dog chasing its tail or the snowball effect.... Poor connections are the culprit, either in the wiring terminals (loose or corroded) or poor contact by the switch or breaker.

I figure you are about an hour ride away from me through some of the nicest rural country in the USA - maybe I'll grab a switch, some wires, a couple of drinks and sandwiches and let you walk me through it up close and personal! I really do hate electrical stuff :icon_toast:

Hope George Williams lets us know the prognosis of this affliction on his bike !

That's what I'm screaming, George!

Been patiently waiting for 7 days and I've not slept in a week waiting for the outcome........ and my medication is all but gone

:D

T150vej to be honest I'm losing patience with this whole forum Maybe I need a new drug prescription The old ones just aren't working !!! It is kind of funny that all these bikers have questions and it gets lost somewhere in the discussion !@#$%

Sometimes I wonder if they get (we give) too much info, but that is our nature to try to help...

Maybe some people want some techie type words to throw around at the bar, or the shop or the dealership or maybe they just want to have an idea of what they are looking at when it comes pay-up time at wherever they took it to get fixed. Heck, this time of year taking a bike to a shop - it could be a month before it even gets looked at.

But I agree, it's really is nice when guys come back and update their thread as to what went down so we can see how close (or not) we each came to hitting on it or what setup worked for them. Learn a lot that way too sometimes. And I do see a fair amount of that and usually try to let them know "we" all appreciate it, with a PM if nothing else.

Well, perhaps I've sucessfully accomplished "hijacker" status by now, so I'm gonna call my doctor (I'm sure he'll answer and be SO glad to hear from me) and ask him about the new meds I just saw on TV. Don't remember what they treated, but the side effects were deadly, so you know it's really good stuff...:D

Hey George.
Yeah, maybe you need to sit back, have a beer and not worry about it. The original poster, (other George) never came back with so much as a "Gee, guys, yeah, it does that and doesn't do this" so, if the thread got hijacked, WTF.
Anyone else just feel a tremendous global tension right now? Every time we turn around, the government is telling us to bend over, that it won't hurt (much) and we'll eventually get to like it. People are starting to get pissed, and the global tension level is climbing. Even those dumb MF'ers that voted for "change" are starting to figger that something ain't right. Recognize it for what it is and relax a little.

Hey guys I'm better now I was going through one of my old leather tool kits (remember those ) from the 60's There and behold were several Rorer 714's Now life is good again ! I don't think Rorer makes them any more Oh well Those good old hippie days !

Nothing quite like a Gorilla Biscuit to knock the edge off ;)

You could always tell when a fresh load came to town here - the local paper was usually 10 pages, but jumped to 14-16 for a couple weeks to cover all the single vehicle wrecks...

Hess, Squeal and T150 - y'all are just scaring people now!

Plus, I think I was the one that actually hijacked the thread in my own self-indulgence. It is, however, the same problem identified by the OP. Once I have a weekend to get in there, I promise to post the hijackers solution. My wife is taking the kids to see her family in about 10 days, so I might actually have some riding time and tinkering time.

Now, where did I put that old leather tool pouch.....

Just as a follow-up, I did have the chance to pull it apart this weekend and tinker. I cleaned all the terminals on the relays and put a little dab of dielectric grease on there when I tightened them back down. The grounds that attach to the terminal block connected to the upper fork area had a few loose ones and in cleaning and what not several of the ends actually broke. So I replaced 3 or 4 of the 6 (I think it was 6). Put it all back together and now my meter still swings wildly, but my turn signals work about 80% of the time.

I didn't try the jump wire across the ignition relay as I was a little unsure and didn't want to blow anything. I suspect I need a new switch and as I have said I will probably get one so I can get rid of the current look anyway.

Is there a tutorial for adding a relay under the seat? I have a 1990 FLHTCU.. Thanks.

T150VEJ, Dr. Hess and SQDealGeorge,

I for one appreciate all the valuable input that you guys give to the forum. i too have a 90 flhtcu with the same problem. had it for yrs, keep saying I am going to fix it. just havent got to it yet. but now i know where to start. I really dont post too much as the SEARCH function works real good for frequently asked questions. i know you guys get tired of answering the same questions over and over. Anyway, thanks for being here for us dummies that think we are wrenches !

later...............

Not that I am aware of, JG. There are slight variations in the wiring harnesses from model to model and year to year, so all anyone could do along those lines would be give general information and a broad idea of what needs to be accomplished to correct the problem(s). So far as a step by step procedure, that would take more pics and text than I have bikes to photo or time to write. But I'll be happy to help you with whatever approach you might choose.

One thing that's hard to grasp is that the acc voltage runs from the main switch thru the starter relay and though it may start OK, the relay can be weak on the normally closed contacts. The acc side of the relay may be good and the start side be weak. Then there's a number of connections throughout the harness, any of which can cause a problem.

I wired mine differently than DrHess and was looking to take care of a somewhat related, but different problem. If the bouncing voltmeter is the only issue, you can simply remove the power lead from it and install another (separate) lead from the voltmeter to the ignition or acc breaker and help it a lot. Alternatively, you could use the arrangement I'm running if turn signals are acting up, or if it's the "dreaded click" issue many seem to experience, you could use DrHess' arrangement. But you could also "bullet proof" it all by intergrating both methods.

Thanks for the roses Paco. I have to thank everyone who ever posted anything here. I've learned a LOT myself, if not by specific info given, by questions asked which have often lead me to seek the answer, even if it did not apply to anything I owned. It's a really great forum, Evo section particularly :)

Let's take Paco out for a beer or some gorilla bisquits ! The pics are coming your way Just remember the beer can front ends

Yeah, Paco, like the phone company, I'm here to help. Actually, teh intraw3bz, y0, have increased the efficiency of our society tremendously. For good and bad, it seems, as the bankers are now more efficiently screwing us to the wall. Anyway, at least we can share how-to's for things that we've been there on. It's the same with my cars on their specific forums. I've been riding Harley's since 1979. Way before I became a doctor. I guess I did it backwards there.

Anyway, JG, I wrote a rough tutorial/guide and posted it here somewhere on how to add an extra relay. Here it is again:


How I Added The Extra Relay.

First off, buy a relay at the auto parts store. I used one that is the same as the regular start relay, located under my right side cover, bolted to the oil tank. You can get the part number off the old relay and have them cross it. It's a common relay and not expensive. Two types are available, one that has a screw mount like the original and one without. Get the screw mount one. Relay sockets are available as well, or you can use wire flag type connectors and push them on the relay terminals directly. Pull the seat off. Mount the relay to the inside of the left panel using a screw that holds the rear brake MC reservoir on. Run a heavy gauge wire from the starter solenoid post that goes to the battery, like 12ga. Put a fuse in the line, like 20 amp or so. You can get a inline fuse holder for the newer automotive flag fuses at radio shack. Connect the other end from the fuse to a normally open post of the relay. Connect the opposite post (the one that connects to the normally open one when the relay is energized) to a heavy wire running down to the small wire post on the starter solenoid. Leave the original small wire there too. Now you only have to energize the new relay. Run a wire (can be smaller, like 16 ga smaller if you wanted) from the starter relay coil to the coil of the new relay. You can run both sides, or one side and ground the other, whatever you want. This way, when the starter relay is energized by the rest of the bike (push button, etc.), both relays engage in parallel and both relays put +12V on the solenoid coil. The new relay puts a full +12V without any of the dozen electrical connections and little bits of wire in the way. It is fused so that if something bad happens, the fuse blows and not the battery (or wire, more likely). When you're testing it, have the battery cables somewhat loose on the battery so you can pull them and stop the whole system should you have screwed up the wiring somewhere.

Thanks for the tutorial. What exactly does this relay do? Sounds like it provides more power to the starter solenoid. I don't have any problems with starting. I have problems with my voltmeter jumping all over the place. Thanks!

sqdealgeorge,

damn its been a long time since i did any gorilla biscuits ! :icon_nut: they were a helluva beer enhancer though !

later......

Thanks for the tutorial. What exactly does this relay do? Sounds like it provides more power to the starter solenoid. I don't have any problems with starting. I have problems with my voltmeter jumping all over the place. Thanks!

JG, that's the relay under the seat that I and some others have done, and that's exactly what it does, that is, provide full battery power to the starter solenoid, ending The Dreaded Click.

The volt meter jumping can be a lot of things, as mentioned in this thread, from "they all do that" to a short somewhere. The important thing about the volt meter is to just monitor it for changes, not absolute values. If it didn't used to jump around and now does, that's a change. I strongly suspect the original poster of this thread ("George Williams") was a troll.

Here is a (primative) drawing of how the accessory / start circuit is wired on Late Shovels and Evo Touring models. This does not apply to Softtails or any others with a tank mounted or under seat ignition switch which use a 4 pole starter relay. You can see there are no less than 10 connection points before voltage ever gets to the load side of the accessory breaker and at least 9 before it reaches the starter solenoid. You will also see that the starter relay disconnects power to the entire accessory circuit when the starter button is pushed, engaging the starter relay/solenoid. Also, the voltmeter is on the very end of the wiring that feeds the accessory items.

One solution is to add a relay under the seat, use the wire that attaches to the "bat" side of the relay as the trigger wire for the added relay and route power from that relay directly from the main breaker back to the acc breaker. And/or, you could route the power directly to the "feed" wire of the starter relay. Alternatively, you could use the trigger wire of the starter relay, to energize the added relay and send power directly to the starter solenoid, bypassing the acc circuit alltogether or in conjunction with the original wiring. (I think that's what DrHess did)



https://www.hdforums.com/forum/membe...c-circuit2.jpg

Yeah, Rufus, that's what I did. My extra relay is in parallel with the start relay and runs power directly from the battery (through a fuse) to the solenoid. Click-Whir-Vroom!

Where exactly is the main breaker coming from the starter solenoid located? Is it one of the 4 breakers that are located under the fairing? The first one on the left when looking straight at the front of my bike has 3 red wires on it. 2 on one pole and 1 on the other. This is the wire that was pretty darn warm when the bike was running for only about 10 minutes tops. If it is.. my guess is the reason it was warm is because my bike still has the original 20 year old battery cables on it and when I peeled back the insulation they were in fairly rough shape at the ends. Also.. although my bike starts everytime, sometimes it just clicks/compression pops/very breifly hesitates and starst and other times it just starts instantly with no hesitation. If I have capacitance (or resistance) because of battery cables that are starting to fail wouldn't that cause the problems I am experiencing?
Thanks for the great diagram!!!

I think I might know where the main breaker is. Could it be right next to the starter relay under the oil tank?

The main breaker on my bike is under the seat. I dunno about yours, but I'd look in that area, and if you see a single breaker near the battery, that's probably it. Be careful of your terminology. Battery cable capacitance is a totally different thing and unrelated to any issue we would experience with our bikes.

Corroded cables should be replaced or repaired. A wire, breaker, connection, etc. that is warm is a sign that there is resistance at that point. If it is not supposed to have resistance, like being a wire, breaker, connection, etc., then there is a problem there and it should be replaced. Some things have resistance for whatever it is they do (everything has some resistance except superconductors, but that's another topic again), so some heat is expected, it's just that a battery cable, for example, should have low heat on it versus, say, a solenoid coil that's on.

JG, I either don't know or can't remember which bike you have, but they are generally under the seat all by themself. There's one wire coming from the starter/battery connection and one going to the main switch and a 3rd that comes from the regulator, on the "load" side but sometimes they get connected to the wrong side of the beaker (doesn't hurt anything unless the reg/wire shorts out). In the dash or fairing, there is one for constant power (radio memory), acc, ign and lights and unless it's been removed, there is a jumper between the light and ign breakers. There are a few exceptions but that covers 99% of the Evo and late Shovel FL Touring models (not FLSTs)

Also, a weak or corroded breaker or terminal connections there will generate heat in the wires on that circuit near to the breaker.

The breaker that has the hot wires on it has 3 red wires. 2 on one side, 1 on the other side. On the side with the 2 red wires.. one of them runs to the battery terminal on the ignition switch which supplies voltage to all the other legs of the switch, the other runs to the main 30 amp breaker that is mounted near the oil tank next to the starter relay. I haven't been able to trace the single red wire yet but I know it goes to connector # 10B. I just don't know what 10B is yet. These wires get hot when the bike is running. Not burning hot but certainly VERY warm. They actually go from being fairly stiff to fairly soft because of the heat. That could be normal because they are not burning or melting.. I just don't know how they are supposed to be with the bike running.

If the entire wire is hot, and not just hot at the end, then that indicates either a wire improperly sized (too small) for the circuit load, or a circuit load over the design spec. As others have not noticed a problem there, I'm going with too much juice in that circuit. Now, why? Is something shorting in that circuit? Is there a huge radio or amp on there, or extra lights? One or the other.