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Posted By: Rancho_Deluxe Electrical problem Turn signal switch - March 06th 2021 5:02 am
This old van wiring is make me lose hair lol. So when I got the van the instrument cluster gauges did work but died at one point, I also had no brake lights. In an effort to solve this I replaced the brake light switch, headlight switch, flashers, fuses, voltage limiter and the turn signal switch. After I replaced the turn signal switch all my exterior lights function 100%. I then I installed the headlight switch hoping that would solve the dead instrument cluster, It didn't, I proceed to fuse with the wiring and reseat the fuses, after that the turn signals and flasher don't work, I do have headlights, brake lights and running lights though. The only lights that work on the instrument cluster are the turn signal indicators, brake sentinel and high beam indicator. I noticed when I use the turn signal while the running lights are on the turn signal indicator lights goes dark and also when I pull the flasher. I should also mention that I've completely bypassed the ammeter. I'm not sure what to do next as I've replaced all the switches.
Posted By: Meanmachine Re: Electrical problem Turn signal switch - March 06th 2021 3:20 pm
Having owned Mid-Dodges since 1974, I have had my share of electrical problems, the older Mopars were well known for them. I wish I would of wrote down over the years the diagnosis or solution to the problem. I know several times I had the lights in the dash dimming or turn signals dash lights dimming, and it was always a ground wire. A good place to start is clean all the ground connections on the sidemarker lights, rear brake lights, and driving lights in the grille. Also the bulkhead connector corrosion was a problems with these vans and the fusible link. I am thinking one time is was even the ignition switch causing the problems, another time I had a bare wire in the steering column, where it runs down the top of the column from the turn signal switch.
Posted By: kursed Re: Electrical problem Turn signal switch - March 06th 2021 4:31 pm
90% of all electrical problems I've come across myself have been due to bad or missing ground connections, the other 10% have mostly been broken wires either completely brittle and broken in half or broken inside the insulation and sometimes faulty switches. Best advice is break out the multimeter and start chasing wires and testing continuity from one end to the other.
Posted By: Rancho_Deluxe Re: Electrical problem Turn signal switch - March 06th 2021 6:48 pm
Yeah, I'm trying to figure out where the grounds are, it doesn't help that there's a bit of a hatchet job with the wiring. There's a ground wire labeled G11-18 W/BK for connection point E for the instrument cluster connector, Do you know where this goes because I cant trace where it leads without unwrapping all the harness tape?
Posted By: kursed Re: Electrical problem Turn signal switch - March 06th 2021 7:35 pm
Nope, sadly that's the best way I've found is unwrap, chase them down.
Posted By: Rancho_Deluxe Re: Electrical problem Turn signal switch - March 07th 2021 4:46 am
[Linked Image]

Well I figured out where the ground for the instrument cluster goes, it connects to the headlight dimmer. I examined the bulkhead connector, seems ok. As far as the ammeter bypass, I have the positive going to starter relay then to battery, and the bypass from the relay through bulk head to black alternator wire. I cut the old black and red wires and spliced them together on the interior of the bulk head. I didn't use any fusible links (I know bad) I attached a diagram of what I did. The circuit board seems ok, don't see any cracks in the copper.

Attached picture 20210306_201745.jpg
Posted By: Rancho_Deluxe Re: Electrical problem Turn signal switch - March 07th 2021 6:57 am
So I just went out and tested the lights and discover another odd thing, when I use the turn signal the lights get brighter but they don't blink?
Posted By: Meanmachine Re: Electrical problem Turn signal switch - March 07th 2021 12:23 pm
I think you have a grounding problem. Is there a 4-way emergency flasher switch under the dash. I think it looks like a small silver canister that plugs in to the system.
Posted By: Rancho_Deluxe Re: Electrical problem Turn signal switch - March 07th 2021 9:15 pm
There's actually 2 of those canisters under the dash
Posted By: kursed Re: Electrical problem Turn signal switch - March 07th 2021 10:17 pm
Originally Posted by Rancho_Deluxe
There's actually 2 of those canisters under the dash

Those are your flashers, replace them both, they're a cheap piece of mind. That way you know you have new ones, keep the old ones for spares in case that doesn't fix the issue. If it does fix the issue, toss those old ones.

I always check fuses and bulbs first, then on to swapping flashers and relays next, then chase wires and test with multimeter.
Posted By: Rancho_Deluxe Re: Electrical problem Turn signal switch - March 07th 2021 10:30 pm
Just replaced them with new ones, didnt solve the issue. The new ones seem a lot heavier then the old ones. Tested voltage on them, the one with 2 wires went to around. 035 and the one with 3 wires shot all the way up to .065 and fluctuated up and down
Posted By: kursed Re: Electrical problem Turn signal switch - March 08th 2021 3:46 am
Originally Posted by Rancho_Deluxe
Just replaced them with new ones, didnt solve the issue. The new ones seem a lot heavier then the old ones. Tested voltage on them, the one with 2 wires went to around. 035 and the one with 3 wires shot all the way up to .065 and fluctuated up and down

You've got me stumped then. I'm tapping out and hopefully someone will chime in and know what's up.
Posted By: Ram4ever Re: Electrical problem Turn signal switch - March 16th 2021 6:03 am
Rancho_Deluxe, the ground which may be involved with your issue typically attaches to the flange along the very bottom of the metal portion of the dash. There should be a quick connect terminal on the headlight switch which has a short wire which connects to that dashboard flange. If it's not connected or missing, anything in the dome/dimmer circuit controlled by the headlight switch could be disabled.

I believe you can't obtain normal lights operation unless the headlight switch is firmly mounted; there is a Copper ground strap on it which has to connect to the metal dash. It may be worth carefully cleaning the area where the headlight switch attaches to the metal dash. Be certain the mounting ferrule nut is actually tight.

The dome circuit is powered through terminal 'D' on the switch, which connects to the junction of multiple (possibly yellow) wires from the door jam switches and one of those courtesy light timer canisters like you replaced. BTW, that circuit works a bit backwards; the door jam switches complete grounds rather than supply power.

The instrument cluster lights come off a terminal (lettered 'I') on the headlight switch, run over to a fuse (4 amps on my 81 Dodge) then onwards to the instrument cluster. Fuses and sockets can corrode. Sometimes previous owners install wire taps for add-on electronics and manage to damage the wires.

Make certain you're not missing any mounting screws, and that any mounting screws are tight. Chrysler was notorious for using mounting screws as electrical ground paths. That ground screw on the bottom of the dash flange was notorious for coming up missing on the vans which had the underdash fiberglass decorative cover... folks would remove the screw thinking it was part of what retained the fiberglass cover.

The brake lights may be an entirely separate issue, yet related to grounding. The electrical ground for the light bulbs in both tail light buckets is on the passenger side. Believe it or not, it's a clip underneath the passenger side taillight bucket, which is simply pinned between the light bucket flange and the body metal by one of the taillight lens mounting screws! If that screw is loose, missing, or has been replaced with the wrong type of screw, (drywall screws are a no-no...) you can easily lose your entire tail light system! If the body metal where the clip touches has become corroded, that can also lead to a total loss of lights. The original lens screws had a partially unthreaded shank. Verify what you've got just to be safe.
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