Electrical nightmare 75 FJ40 FST (1 Viewer)

[kmj64]

Looking for a little help before I yank out whole wiring harness and attempt something I shouldn’t. Headlight, left turn single and horn do not work. The grounds I have absolutely cleaned are frame and battery. I have taken fuse box out and used the dremel tool it and nothing but solid clean brass on all connectors. Hazards work, I pulled it out last week and sprayed electrical cleaner in the plugs and reinstalled. At first they would not come on but now they are.
Does anyone know where these clips in these pics should be connected. They are wrapped up in main harnes coming off fuse box. Is it time for flasher or turn signal lever?

Thanks for ANY suggestions

 

[kmj64]

@CenTXFJ60

 

[Catfish28]

If I remember correctly the larger one is the emissions computer. Other is the full throttle sensor. Leave both off assuming you're desmogged.
If it were me I'd just try and track down the gremlins for the 3 issues you have. All should be straight forward. Horn and headlight should be easy by Checking to see if you have 12v at the light and horn. Signal can be a bit more complicated but the fact that you have hazards is a good sign. Do you have led's.

 

[kmj64]

No LED’s, I’m thinking there is a ground I’m over looking

 

[thebigredrocker]

The single RB(red/black stripe) with the nick just before female bullet goes up through windshield to interior light near drivers left ear.

What are the wire colors on the two pronger? Flasher wires should be GW(green/white stripe) and GL(green light blue stripe)

Perhaps the big white plug with zip tie is emissions inspection connector

I bet the non-op turns, horn, light will be dirty/coroaded connections.

 

[CenTXFJ60]

I’ve helped Kevin try to track down these gremlins with no luck. There is a click at the horn relay when depressing the button but no activity at the horn.

 

[ToyotaMatt]

View attachment 1656217 Looking for a little help before I yank out whole wiring harness and attempt something I shouldn’t. Headlight, left turn single and horn do not work. The grounds I have absolutely cleaned are frame and battery. I have taken fuse box out and used the dremel tool it and nothing but solid clean brass on all connectors. Hazards work, I pulled it out last week and sprayed electrical cleaner in the plugs and reinstalled. At first they would not come on but now they are.
Does anyone know where these clips in these pics should be connected. They are wrapped up in main harnes coming off fuse box. Is it time for flasher or turn signal lever?
View attachment 1656210View attachment 1656208 View attachment 1656209
Thanks for ANY suggestions

Hey Kevin ,

What is the Single Fat Green W/ white tracer stripe wire all by it self coming off the steering column by the black electrical tape for ?

Its severed and all by it self to the RH side of your photos; above ?

No body so far has mentioned this wire , and its large gauge suggest its a primary wire of some sort from the turn signal switch / Dimmer switch

My Haynes Manual page 227 shows the GW wire going from the flasher turn signal & hazard to the hazard switch

or

GW is also for Horns ..........

 

[thebigredrocker]

Did you guys test the horn(s) by hooking directly to the batt (+) &
batt (-)?

If they don’t work I recall a couple recent threads on how to adjust them. I believe matt1260 got some help and perhaps ginmtb?

Kevin,
There is a particular Coolerman post I think anyone struggling with flashers should read. It is in a turn signal thread. Here’s how I find it—>

Keywords: current driven
Posted by member: coolerman

 

[thebigredrocker]

Here’s my 12/75 “76” turn signal stalk plugs. Dang if I can find a female bullet for that GW wire. All my lights were working when I yanked the stalk. Hey @BeerM3 do you have the GW bullet hooked up yet?

 

[Catfish28]

If horn is clicking but no horn it probably just needs adjusting. Cleaned and adjusted mine yesterday. Adjustment screw is on back as I'm pointing to in pics. Very little adjustment goes a long way with tone if the horn. If that doesn't get it then the rivets can be drilled out and all contacts cleaned.

 

[ToyotaMatt]

My man @Catfish28 Drilled out and replaced his Rivets on his horns !


seeing this done is why Im Addicted to MUD

 

[Catfish28]

Could also be referred to as "horn porn" I suppose.

 

[BeerM3]

View attachment 1656617 Here’s my 12/75 “76” turn signal stalk plugs. Dang if I can find a female bullet for that GW wire. All my lights were working when I yanked the stalk. Hey @BeerM3 do you have the GW bullet hooked up yet?

No, I never needed to hook it up to anything. It's an orphan of wiring design changes Toyota was making at the time. Here's where I found the answer.

 

[BeerM3]

Headlight, left turn single and horn do not work.

I had a similar issue on my 1/76 and it was a multi-part problem. All of those listed detour through the steering column switch. Have you pulled the steering wheel and checked that for corrosion or a short? Maybe a melted wire in the harness? The PO put a 40amp fuse in my turn signal circuit and fried a line. After replacing the turn signal switch my headlights and horn worked again but the turn signals still didn't. After pulling the hazard switch, prying it apart and cleaning, tightening up the connections that fixed the signal issue.

 

[CenTXFJ60]

Matt, here’s the green/white wire. Does not route through the main clip as they are all accounted for. Can’t find any other wires in the dash area that seem an obvious match. But it definitely is part of the turn signal electrical board. And should the wire harness be grounded to the A pillar on this year? The pic included shows the ground from a 78 model we pulled out (parts rig). Also, a dumb queistion...how do you hit the horn direct to the battery? I ran a wire from the + terminal directly to the single post on the horn. Don’t know how to ground it so I touched a grounded wire to the horn mounting bolt. Not sure if this is correct. Either way there was no reaction from either horn.

 

[thebigredrocker]

I bet those two WB’s with the ring ground the ENTIRE harness to the tub. I would run a hidden ground strap from driver side frame to tub to certain tub has good ground path. I also added a rear (frame to tub) ground strap.

Right idea on the horn testinh @CenTXFJ60, if the surface between mounting bolt and horn mount needs cleaned, mearly touching the bolt may not be a good enough ground. I’d just scuff up the horn mount, gator clip that spot and then clip to battery -.

On the turn signals, my fenders weren’t grounded to the frame so I ran ground straps to them. Probably overkill and perhaps not ideal if you are trying to keep that brautiful fst factory looking.

 

[CenTXFJ60]

So the horns don’t work. Pulled some off one of my 40’s and did the same test and they fired off. Will look into the adjustment post above. And Big Red, will make some grounds as you mentioned. I have little experience with 40’s. My 60’s all have a ground to the A pillar so I find it unusual this 75 does not.

 

[ToyotaMatt]

Per @BeerM3 , The 1975 hazzard switch Internal Contacts / GUTS , As I Refurbish these , I see more & more are seized Up

and short out or simply are not making good electrical current flow contact across the circuit board itself . I have seen Bad

Terminals in the large unique Waffle Connector This is simply a Age & Time Phenomenon Issue ........

 

[CenTXFJ60]

So the horns don’t work. Pulled some off one of my 40’s and did the same test and they fired off. Will look into the adjustment post above. And Big Red, will make some grounds as you mentioned. I have little experience with 40’s. My 60’s all have a ground to the A pillar so I find it unusual this 75 does not.

. Took the left side horn apart and looks really good. Does smell like something has been burnt in there and the close up shot shows the white plastic is melted. Which direction do you adjust the screw on the back? In or out?

 

[CenTXFJ60]

Ok. No need to reply on the horns. Definitely melted down. Just opened the second horn.

Result of two electrical novices working on a 40 . This did happen almost a year ago as Kevin mentioned above. Assuming they shorted via a bad ground