First, thanks for all the support the forum has shown as I muddle my way through this 68FLH rebuild. You all have my endless appreciation, and I'm grateful that you put up with me being a heavy user at the moment.

That said, having some wiring problems, and I know this is the place for the best help. I'm no electrician, so I'll try to summarize as best I can below to paint the entire picture:

1. New wiring harness, new ignition switch (heavy duty, non-pole unit). As far as I can tell, I've followed wiring diagram to a T...so far. What I mean is here is that the headlight, spotlights, directionals, stop lamp, stop lamp rear switch, horn button, starter button, hi-low switch, directional switch, signal flasher unit are not all wired into the grid yet. Everything with loose ends has electrical tape terminals. No stop lamp front switch/dimmer switch installed.
2. New dash light (5-bulb) set installed. White hots, black grounds. I drilled an extra terminal hole through the dash mount so I could wire the oil pump indicator light and generator indicator light separately, like this.
3. Solenoid, starter relay, starter motor, 30-amp circuit breaker all temporarily bolted/zip-tied to a wood plank (inner/outer primary not installed yet). Battery sitting sideways in cage, reading 12.4 to 12.5. Frame was painted, I sanded out the grounding mount.
4. Coil installed, plugs wires not in.

Last night, wanted to test the wiring, so connected the battery for the first time. Dash base assembly bolted to frame. Turned the ignition switch on. Circuit breaker popped. Lots of fiddling, lots of circuit breaker popping. More fiddling. Neutral light popped on for a second. Small success, I think, followed by more failures. Attempt after attempt -- see sparks at top mount of dash base. Gotta be a something hot touching the mount plate, I figure. Disassemble terminal posts, reinsulate with hi-temp electrical tape and try again. Still sparking on top mount. Use voltmeter, getting what I think are mostly accurate readings. Switch terminal at headlamp reading funny? Remove both red supplies from switch terminal. Caught sparks when one hit the ignition switch housing. More fiddling, more trying. Both red supplies back on, try again. One of the supply terminals glows RED HOT when ignition switch is turned on. Figure that's a critical issue. More fiddling. Double check all connections in terminal box are accurate. Yes. Double check all current connections to panel are accurate (note that as explained above, many "accessory" items are not wired in yet). Yes. Now it's 11pm, so I try one last time. Circuit breaker pops. Decide to shut it down. Disconnect the battery, live to fight another day.

That's the scene, here are the basic questions.

1) What could be causing high-temp arcing at the ignition switch supply terminal?
2) What could be causing the dash plate to spark at the top mount?
3) Can not having the accessories hooked up (lights, switches, etc.) lead to these issues, because it's creating incomplete circuits?
4) Would a bad ground connection (painted frame not sanded enough) cause any of these issue?
(BONUS QUESTION 4A: I don't have a grounding strap attached anywhere yet...could that help? If so where should it be connected?)

If I'm a gambling man, I'd say I have an ongoing short issue in the dash plate or a bad ground connection. Short of disassembling the entire dash mount and starting from scratch to TRIPLE ENSURE the plate isn't accidentally hot, and resanding the frames ground mount (which I'm sure I'll just do anyway out of an abundance of caution), I'm not sure what else to check. Last thing I want is for this thing to go up in flames on accident because I did something incorrectly.

As always, any and all help appreciated. This is not an urgent issue necessarily, probably won't be back on it until next weekend. It'd just be nice to have a game plan since I'm not electrically inclined.

 

The the bulbs are connected incorrect

you need to picture up the neutral switch on the trans top left side top of the case - with out seeing it i do not know if it has the correct trans in the bike

the oil light pressure switch on the oil pump picture that as well it could be correct nut then again i deep a picture

the gen light the one wire goes directly to the A term on the generator - IF you have the correct generator its the one at 4 o’clock on the gen looking at it from the left side and it has 2 wires on it one to the regulator and one to the bulb

the other term is the F term its at 12 30 and only has one wire to the regulator

again if you have communist parts then all bets are off on correct locations

take some pictures and post them

 

Per suggestion, some pics are attached below. Sorry I forgot to grab the pics of the generator connections. I drilled a hole for an additional terminal post in the dash plate per this replica design. Other than the dash lights, no other lights are attached yet -- horn, starter, light or directional switches not attached either. I'm hoping someone might be able to spot something out of sorts here attributable to user (builder) error. Like I said, I'm no electrical genius but outside of adding the additional dash plate terminal post I think I've followed the service manual diagram to a T -- it seems pretty straightforward. But outside of following a schematic I don;t have the skill set (yet) to troubleshoot circuits or bad connections with any precision. That's what makes me wonder if as johnjzjz pointed out the bulbs are connected incorrectly (i.e. the outside socket body wires are actually hot and the middle wires are ground), which is maybe why the dash plate is sparking against the mount? Mad confusing because I wired them just like the replica dash plate showed. Anyway, hope the pics are helpful to anyone wanting to help diagnose any obvious problems. I probably won't have a chance to tinker with it until the weekend. As always, appreciate any help I can get!



top view of schematic. J8 gets B&Y from C // J8A gets Y from oil // junction 7 gets B grounds (outside wires) from oil/gen lights // J7A gets G from Gen (A) ///// ignition supply (1) gets Rs from C & A // ignition (2) gets Gs from speedo & C // ignition 3 empty // ignition 4 gets G from A // Ignition 5 gets Y from C and B from J7 (i cut a wire to go there)

Bottom scheme of dash panel. Lights are labeled with whites (hots) from middle and grounds (blacks) from sides (external, or socket body). I laid it out like I saw a in a replica dash panel. I'll add the link to that replica panel in the message body.

Solenoid, (top) red to +ve, bottom to starter motor, green to starter relay tab 2 (1st bottom tab)

Regulator, battery tab has connections to terminal box #39 (with feed to supply switch 1) // to starter relay tab 1 (side tab) // to 30 amp breaker (with feed to +ve)

30 amp breaker -- battery side to +ve, arm side to regulator's battery tab

Coil top gets black from Terminal Box 41 and bottom gets black from "Circuit Breaker" (distributor).

Neutral switch -- two blacks from terminal box 41 & 42

Terminal panel -- conduit C connections are Y to 25, G to 9, R to 10, B to 24. Another B from 31 to starter relay tab 3 (2nd bottom tab)

Physical view of top side of dash plate, following the schematic also posted.

Physical view 1 of the bottom side of dash plate, following the schematic also posted.

Physical view 2 of the bottom side of dash plate, following the schematic also posted.

Switch Supply (Ignition terminal 1) sparks when i touch the wires to the actual ignition body on accident. One of the red wire terminals got RED HOT on one of my attempts at turning the switch on. Something not good going on there.

Oil pressure switch , one yellow to J8A in dash plate.

Physical view of top side of dash plate. Forgive all the electricap tap, but since the plate was sparking to the top moount I was working through a process of elimination to make sure everything was insulated properly and the plate wasn't hot.

Top dash plate mount, which is where I'm occasionally catching sparks from when the switch is turned to any position other than off.

 

View number 1 has the black wires for the bulbs grounded to the dash plate - incorrect

they must be isso from the dash with the fiber washers and one with a young so nothing touches the ground of the dash number 5 on the switch is hot to the number 7 terminal

 

Well, that would certainly explain the sparking from the dash plate! I'll definitely grab some more fiber insulators and get that sorted. To be clear, the four "diamonds" in my schematic represent the ignition mounting posts. Forgive my ignorance, but I have to ask for clarity -- when I separate the three dash light grounds from the plate with fiber insulators, will I also need to insulate the entire ignition unit from the dash plate with fiber discs too? Or does the ignition unit insulate itself from its own mounting bolts by how it's built? Again, sorry for what may seem like dumb questions. I can read a schematic layout but it doesn't translate to anything meaningful for me with regard to how it's supposed to operate what with the volts and the amps and the ohms and whatnot.

I thank my stars for this community every day. Ups to you johnjzjz for taking the time to help.

 

No the ignition switch is not grounded too anything its a live 12 volt hot only at different switch spots - its transfers the voltage from off to on

 

I was worried my question would be unclear. Looks like it was. Hate to be a pain, I just want to make sure I'm separating the right things from the other right things.

So let's say I lift the three ground wires off the dash plate with fiber washers. Those ground wires are still attached to one of ignition unit's mounting bolts, which would still be touching the dash plate metal-to-metal, just under the fiber insulators, right? So when I ask if the ignition unit is self-insulated, what I'm asking (hopefully clearer this time) is are the ignition unit mounts separated from the ignition unit internally in any way, like through a layer of bakelite? I mean, the whole ignition unit isn't serving as a ground for the dash lights, right? So what am I missing here?

If you were closer, brother, I'd just float you a Benjy to walk me through it so I could see exactly what you'd be doing to fix it. I've come a long way here but apparently still not enough. lol

 

It simple - dont confuse it

the mount for the ignition is just that its mounts the switch NOTHING else does it do - the screws hold it in place - the electric part of the switch is all buy its self has nothing to do with the switches mounting

the 3 main dash lights neutral oil and generator all power the bulb center and the second wire ( call it a ground ) goes to the neutral switch and that is the ground - the oil light sender is the ground - and the generator A terminal is the ground — nothing else no pass go and use a jumper - you I could run wires just to those items alone that world work as well -

 

Got it. A million thank yous. I think my problem was following the replica layout, which had three grounds going to the ignition mounting post. I'll bypass that completely and run the directional and neutral grounds to a dedicated insulated post up top. 100 to 1 says that's what was causing my issues. I was serving two masters trying to follow the SM diagram and also the replica plate layout.

I will update here once I have a chance to get to it. There may be more to troubleshoot later, but this should go a long way toward helping me get there.

Thank you brother.

 

Update -- Got antsy and messed around with this last night. All seems to be wired correctly now, plate no longer hot. I was confused for a while because I still wasn't seeing dash lights...until i realized the breaker was still popping. I tightened all the connections one by one until I tracked down the offender...the brake switch terminal lost its electrical tape insulation end and was shorting out bouncing between the primary and trans housing. Retaped it, let the breaker cool, and the next time I turned her on I got neutral and gen lights, no breaker pops. Untaped the tail light terminals, held them in two places against a bulb housing to check the circuit, and it looks like we're golden on the *** end too. BAM! Thanks so much for your help johnjzjz, couldn't have done it without you.

One (i hope) final question at this point....should I be concerned the oil light didn't come on at this point? I installed a new oil pressure switch but have no oil (liquid) lines hooked up yet. It is tied in to the dash. I wasn't sure if that's one last bit of troubleshooting to take care of now, or if it's just a quirk because the switch is new and no oil lines are hooked up. Based on youtube videos I've seen I'm pretty sure the light should come on with the other accessory lights. I checked and I am getting current at the socket. Since everything is grounded a bit different from my original schematic, I plan to check again tonight to make sure I just didn't overlook something obvious. It was getting late and I was losing steam. Appreciate any insight there.

After I figure that out, I think the dash can be buttoned up and I can start loosely zip tying all the lines to the frame. Won't tighten anything down until I can get the headers attached, so I have some wiggle room if things get too close for comfort.


Happy Humpday HD Forum family.