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Old 09-21-2021, 03:34 PM   #1
Furno68C20
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67 Blinkers not working but hazards do

I've been working on this blinker problem for a few days now.

All hazards work except this driver front. but this is probably a bad bulb or ground.

This is what ive done so far.

Removed TS switch and cleaned it. checked continuity from the the c- connector to the switch on all wires. All are good. switch is back together.

removed the fuse block and cleaned terminals on both fire wall connections.

with a test light i checked voltage at fuse panel.

I get 12 volts at one of the hazard pins on the fuse panel where the flasher plugs in.

I'm not getting 12 volts on the signal pins while in accessory key position.

I took the fuse panel off and looked behind and there is a pink wire that connects to the fuses that i circled in the pic attached. Im guessing there is no voltage to on the pink wire and wondering why.

I read somewhere that 67 accessory voltage is different from later years where they use a brown wire from the ignition switch to feed these fuses.. Can some one clarify what the difference is in 67 accessory feeds?

in the pic the circled fuses all have 0 volts with key off and key on(accessory)

any help thanks
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Old 09-21-2021, 03:54 PM   #2
pjmoreland
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Re: 67 Blinkers not working but hazards do

In 67 there was no accessory position for the ignition switch. There was only off, run and start. In 68-72 you could turn the ignition switch to the left (CCW) for the accessory position.

The pink wire that should be powering those four fuses you circled in your photo should get power from the ignition switch, I believe. Maybe you've got corrosion issues on the back of the fuse panel where the pink wire attaches. You might want to see if you've got 12V on the pink wire at the ignition switch end of it.

Schematics for 67 can be downloaded here:

http://www.mediafire.com/file/zq2o83..._1966.pdf/file

Scroll down to page 83.
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Old 09-21-2021, 04:02 PM   #3
cwcarpenter98
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Re: 67 Blinkers not working but hazards do

I had a wire on the fuse block in my 63 corrode to the point that I lost all dash lights and brake lights. It was on the back side and had a rubber sleeve around the wire and plug that ended up holding water. Yeah, my cab's a little leaky

Fixed that connection and all lights worked again. With how your terminals look on the front side, you probably are having some sort of connectivity issue on the back side. Find the terminal on the back side for that fuse you aren't getting power to and wiggle it around a bunch with a screwdriver or something. If you suddenly get power, you've got a corrosion issue somewhere in the terminal. I replaced my fuse block because of that corrosion issue I found with the taillight circuit. Then that replacement had the wire issue mentioned first
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1963 C10 - Frankentruck 283, 3 speed with overdrive
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1963-ish truck bed trailer - Half-Wit

1981 C10 - Penny 305, th350

1995 Dodge Dakota Sport

"I'll put it simple: if you're going hard enough left, you'll find yourself turning right." - Doc Hudson
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Old 09-21-2021, 05:10 PM   #4
Furno68C20
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Re: 67 Blinkers not working but hazards do

I'll take the fuse panel off and do some checks. Trace that pink wire. I'll give an update if i find anything.
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Old 09-22-2021, 11:55 AM   #5
Furno68C20
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Re: 67 Blinkers not working but hazards do

Did some wire tracing last night and found that the pink wire going to those fuses was fed by the ignition switch in the Run position. After a lot of terminal cleaning on the fuse block i was able to get good continuity from the ignition switch to the fuse block.

Dirty old terminals can really mess up a circuit. Both the hazards and signal blinkers are functioning properly.

Thanks again to everyone.
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Old 09-22-2021, 12:04 PM   #6
pjmoreland
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Re: 67 Blinkers not working but hazards do

Very good. I think it is safe to say the majority of the problems these old trucks have with their electrical systems are caused by corrosion. That, or strange things previous owners did to the wiring system for unknown reasons...
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Old 09-22-2021, 05:36 PM   #7
cwcarpenter98
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Re: 67 Blinkers not working but hazards do

Sweet! Happy to help!
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1963 C10 - Frankentruck 283, 3 speed with overdrive
Overdrive wiring here
1963-ish truck bed trailer - Half-Wit

1981 C10 - Penny 305, th350

1995 Dodge Dakota Sport

"I'll put it simple: if you're going hard enough left, you'll find yourself turning right." - Doc Hudson
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