Nuther Brake light Post

[zetasig]

Alright guys. 1970 FJ 40.

Both Brake lights and turn signals to the rear not working.


Fuses Good and checked
Brake Light switch new from Kurt at Cruiser outfitters.
Front signals work. (sometimes)
Both interior indicators light up (sometimes)
Flasher new and was working until yesterday night.
Rear signals are from a trailer store. Recessed into the tub. The bulbs are good.

When I pull the headlight switch all of the running lights work. Even the rear brakelight running lights. So there is power back there. I know I have good ground there too.

As of yesterday all that was not working was the driver side Pulse for the brakes and flasher.
The Passenger side was working properly.

So with the key on and the driver side indicator on (front turn signal flashing) I start down the orange and green stripe wire from the dash working back. Checked it with my tester on three different areas. all were working and making the tester light flash. I get to the very rear. after the loom splits for the driver side and nothing. Great I think heres where the bad wiring starts. But now nothing works to the rear. Driver side or passenger side. The Passenger side which just worked like 5 mins ago does not now. (the running lights still work, just nothing else)

I went back and the turn signal stopped flashing on both sides. This is the gremlin if you will.

I tested the brake light switch again and it does light up when I press the brake pedal so. I know its hot under the dash.

My thoughts... Bad turn signal switch? I sprayed the top end with brake parts cleaner and it moves more freely.

Any insight into this one? I dont have an Ohm meter. and dont know how to use one

I do understand the rear harness. Green is running lights. Green/yellow Passenger side flasher and pulse for brakes.
Green/orange Driver side flasher and pulse. (thanks IDAVE)

What do you think.

 

[Poser]

That you have a poor connection at the junction and that you need to take that area apart and re do all of the PO splices that are creating this issue for you.


More often than not, the switch is not the culprit....especially if you have had power back there just a bit ago...I would look at those connections, and see what is going on....



Good luck!


-Steve

 

[ortayga]

I have similar problems. I took my Brake Light Switch out and worked it manually while switching blinkers on and of. It acted like the switch mechanism was messed up. By working it manually it would work correctly, then it would quit blinking or a brake light would quit. Very inconsistent. My Brake Light Switch looks like it is new also.

I'm going to get a new one soon as Kurt gets some more in.

Its probably not what is wrong with your rig, but thought i would mention my situation, and try and participate a little.

 

[zetasig]

Guess i will pull all the connections from the Signal swich under the dash and clean them up some.

Its odd but is seems like the power that comes into the signals themselves is whats getting clipped some how before it hits the signal switch. Everything under there is OEM. The only non OEM stuff is the back signals which I put in at the very rear of the harness. And one of them was working.....

 

[zebrabeefj40]

Warren,

Pull new wires from the front to the rear of the Cruiser. If it is anything like the '76 I have there are 4-5 connections from the front to the rear that need to be good. Ditch all that crap and run straight back to the lights from the firewall connector under the heater blower motor and be done with it. A trailer wiring harness would probably work well and are cheap at Wally World or you favorite parts emporioum.

Nick

 

[zetasig]

Uhhh, Well I did run a new wire to the passenger side. It works. Brakes come on when pressed, Turn signal flashes, and the running lights. Then it stopped. Dead again. WTF.

I pulled apart every connection right under the speedo and cleaned them all with brake cleaner. Singled out the one rear wire G/O and ran a new one to the turn signal.

Same thing, it just works then stops. Brakes and signal lights to the back and signals on the front.

I took the wheel off and cleaned and lubed there too.

I have it to the point right now where I have key on. and brakes pressed, The brake light is on. I hit the left signal and the brake light goes out. turn off the signal and the brake light comes back on?

Any ideas.

 

[Poser]

The brake light part of the 1157 bulb and the turn signal share the same filament....


When working properly, when your foot is on the brake, and you are turning right or left, only one side will have a brake light....the other side will be flashing with the same brightness as the brake lamp.

 

[zetasig]

Okay, that makes sense. Still the power is getting clipped from somewhere, Its as if there is a bad connection from the wire(s) providing power to the signals. at the switch. Assuming the switch is good and all the wires running back are good its gotta be before the power gets to the switch . Anyone got an idea what wire that might be. I have about 15 different wiring diagrams and its not making sense to me.

When it was working earlier I got to 22 flashes before it just stopped.

 

[el_diabolico]

I had the exact same problem on mine. T/S were intermittent at best. I found my Turn signal flasher was bad. Unfortunately this monster is located under the dash, behind the fuse block and recessed up a bit. Got a replacement at Napa (X-ref OEM # with NAPA Part #) and relocated it to a more user friendly spot.

 

[zetasig]

I have a newer Napa flasher. Maybe 1 year old. I suppose for 12 bucks I can get a new one to see. But it appears that the problem is with power getting to the signals from where ever it comes from.

I should add that the rear signals are aftermarket, They have a dual fillament bulb. and are sealed they are for a boat trailers so no water gets into them. Its a three wire system. One wire on the tail light goes to ground. One wire for running lights. and one wire for the stop/signal part.

 

[slickrock]

Uhhh, Well I did run a new wire to the passenger side. It works. Brakes come on when pressed, Turn signal flashes, and the running lights. Then it stopped. Dead again. WTF.

I pulled apart every connection right under the speedo and cleaned them all with brake cleaner. Singled out the one rear wire G/O and ran a new one to the turn signal.

Same thing, it just works then stops. Brakes and signal lights to the back and signals on the front.

I took the wheel off and cleaned and lubed there too.

I have it to the point right now where I have key on. and brakes pressed, The brake light is on. I hit the left signal and the brake light goes out. turn off the signal and the brake light comes back on?

Any ideas.

I might be wrong but doesn't power ot the blinkers first go through the hazzard switch? Check for power comming off the switch.

 

[zetasig]

Will do, I will pull the hazzard, clean all wires and see if that doesnt fix it. Thanks for the suggestion.

 

[zetasig]

FIXED.....

Well a series of things.

I replaced the Flasher unit with a new one. and ran two new wires back from the signal under the speedo all the way back to the signals. Cutting out the G/O and G/Y wires.

This seems to have cured the problem. Everything is working as it should. Thats really a first for this truck!!!!

Troubling about the flasher as it was only a year or so old, and really never used.

Thanks for all the help and replys.

Well its almost legal to drive now.