Volt meter drops 90 flhtcu
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Stage I
Joined: Jul 2009
Posts: 1
Likes: 0
From: Charlotte, nc
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?
Cruiser
Joined: Nov 2007
Posts: 216
Likes: 2
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.
Road Warrior
Joined: Dec 2007
Posts: 1,854
Likes: 20
From: Eagle River WI
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 ?
HDF Community Team
Joined: Dec 2005
Posts: 5,374
Likes: 2,570
From: NC USA
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 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.
Road Captain
Joined: Jun 2008
Posts: 640
Likes: 13
From: Hickory, NC area
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 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.
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.
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,195
Likes: 3,084
From: NW AR
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.
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Road Master
Joined: Jun 2007
Posts: 842
Likes: 47
From: New Hartford CT
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.
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HDF Community Team
Joined: Dec 2005
Posts: 5,374
Likes: 2,570
From: NC USA
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...
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...
Road Captain
Joined: Jun 2008
Posts: 640
Likes: 13
From: Hickory, NC area
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?
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?