Possible to jumper turn signal operation? (with FSM diagram)

[jogirob]

Hi all, turn signals don't work. Replaced flashers, fuses are good, scrubbed some contacts, nothing so far. I want to factor out the switch.

Since it requires special tools (steering wheel puller) to get into the turn signal switch I was wondering if I can intercept the wiring before it goes into the steering column and somehow jumper some wires into making either the right or left turn signals operate.

For example, if I wanted to get the right side to flash: do I connect a live wire to "Right Front-Tan wire" and "Right Rear-Brown wire" Or do I jumper from "Turn Signal Flasher-Red wire" to those Brown and Tan wires?

 

[jogirob]

Higher resolution.

 

[Nacho-RT74]

Ok, let's see.

Input for turning is the red wire at plug, which is the one coming out from flasher. It must be hot in ACC and RUN.

This source begings to blink when bulbs are being feeded, making the load going through to heat the flasher, then colds down, then gets hot... this opens and closes the bimetallic inside.

If you link out ANY of the 4 corners wire to the red wire, the blink will never stop. This is what the turning switch makes inside.

So, to prove the switch is in fact damaged you can jump out any of the 4 corner wires ( brown, tan, light green or dark green ) to the red wire on same harness. This would make to blink that corner.

With this you can deduce there is not a comfortable way to by pass the switch if is not working propperlly. You could make to jump out, let's say if just rears are not working ( dark green and brown ) with fronts ( light green and tan ) to solve temporally the problem, ALTHOUGHT when giving brakes, the front blinkers and pilot lights on cluster will light up as well, but will have at least rear turnings and the switch function still available partially

 

[Nacho-RT74]

i have had once a brakes light problem and I thought it was the switch... finally found the problem was actually the white wire ( which is the one what comes from brakes pedal switch) on plug. The terminal was loosen from the insulator and the wire allmost broken at the terminal

 

[jogirob]

Ok, let's see.

Input for turning is the red wire at plug, which is the one coming out from flasher. It must be hot in ACC and RUN.

This source begings to blink when bulbs are being feeded, making the load going through to heat the flasher, then colds down, then gets hot... this opens and closes the bimetallic inside.

If you link out ANY of the 4 corners wire to the red wire, the blink will never stop. This is what the turning switch makes inside.

So, to prove the switch is in fact damaged you can jump out any of the 4 corner wires ( brown, tan, light green or dark green ) to the red wire on same harness. This would make to blink that corner.

With this you can deduce there is not a comfortable way to by pass the switch if is not working propperlly. You could make to jump out, let's say if just rears are not working ( dark green and brown ) with fronts ( light green and tan ) to solve temporally the problem, ALTHOUGHT when giving brakes, the front blinkers and pilot lights on cluster will light up as well, but will have at least rear turnings and the switch function still available partially

Aha that makes perfect sense! Will try that thanks.

 

[jogirob]

Ok so when jumping it pretty much acts exactly as when operated from the switch so the switch is fine.

While chasing the 2 wires that go to the tails (DrkGrn and Drk Brwn) I found out that the previous owner totally chopped em off!

So can I just splice these chopped off left and right tail signal wires into the "hot when brakes are applied" wire, Or splice it into the "on when parking lights are turned on"? For simplicity sake I think I'd bypass the old harness and wire straight to one of the light bulb's 3 wires, just need to know which one.

 

[Nacho-RT74]

You can get a damaged switch ( partially ) even if front turning lights works. I mean, if ANY of the signals fails you can get a damaged switch. BTW you never told if you have ALL 4 corners turning failing or just rears or just fronts... I was just talking!

wow what a nice rear tail light harness!!! The good on this is the tail light section seems to be still in decent conditions easy to rebuilt.

Honestly? I'd get the harness from end to end. They are not hard to find, since ALL 71/74 B bodies got the same, including 4 doors, and uses to be cheap. Just need to remove driver side kick panel, unplugg it, remove door sill plate, bottom of rear bench and beging to pull it out.

will need also to unplug the gas tank sender and the trunk lid light. Gas tank sender wire got a grommet on trunk floor. trunk lid light got a plug around wheel housing.


if you decide to fix this mess... just get them rebuilt from the chopped wire up to the plug. Terminals are called MOLEX, and not hard to find up there ( Radio Shack in fact got them even with the plastic insulator since is the same plug used on PC power sources ) you don't need to jump out anything, just rebuild

 

[Nacho-RT74]

this is one example of the full harness

https://www.ebay.com/itm/MOPAR-1972...069459?hash=item23ab604913:g:Lj8AAOSwKsZbh1E4

with some fresh new tape will look like new

but if you dug into some JunkYard around I bet will get in in $10 LOL.. you don't need to spend this:

https://www.ebay.com/itm/71-72-Plym...759389?hash=item3b1cc53f9d:g:4egAAOSwv~law7ex

LOL

Moparmarks around here uses to have a good stock of 3rd gen parts.

 

[jogirob]

Oh I had some long thread started up somewhere already and didn't want to clutter up the post but here you go: Lights turn on fine when parking light is on. And tails shine bright when brakes are applied.

Only front passanger light flashes and only when hazards are activated. I get both dashboard signals indicators when doing that.

No external markers flash when using turn signals. Only get clicking from the flasher unit when turn signal is activated to the left. Left dashboard indicator works during this. When signaling to the right absolutely nothing happens.

 

[jogirob]

Was thinking of patching the cut of signaling wires into the bulbs because the previous owner has some custom wiring going on into some LED tail lights.

All this mess just because the guy wanted LED's :-/

 

[Nacho-RT74]

If brakes shines when brakes are applied with all those wires cut then get a replacement harness! Brakes run through same turning wires ( dark green and brown ) so there is something weird there.

I'd try to get back to stock again and begin from there if something more appears

 

[jogirob]

If brakes shines when brakes are applied with all those wires cut then get a replacement harness! Brakes run through same turning wires ( dark green and brown ) so there is something weird there.

I'd try to get back to stock again and begin from there if something more appears

Yea they had custom wiring from the brake switch in the cabin and spliced into the 2 brake lights. It was obvious that they never intended to have signals at all.