Delay wipers

[Rob P]

I'm adding delay wipers and I think I'm having the same problem I had when I undertook this endeavour with a 78 Corvette. The truck is a 78 GMC and never had delay wipers. I added the switch and the delay box but still no fun. Everything works but the delay. I read in the 78 shop manual that a wire plugged in to the ACC port in the fuse box. Can someone tell me what color wire does this splice to? I'm assuming this feeds power to the delay mechanism. On the 'vette, I had the same issue until I figured out I needed a special wiper motor cover and needed to splice a wire coming from this cover into a green wire.

 

[Snoots]

Try this

 

[bucket]

For '78-'83 trucks, it's just a matter of plugging in the delay box and wiper switch to the existing pigtail in the dash. Sounds like a bum switch or box.

 

[Rob P]

Tried three new switches and three boxes. Nope, the manual for 78 clearly states that a lead goes to acc port in fuse box. 78 appears to have been a disaster for gm wiring

 

[Snoots]

Just find a port that only has 12vdc when the ignition switch is on.

 

[bucket]

Tried three new switches and three boxes. Nope, the manual for 78 clearly states that a lead goes to acc port in fuse box. 78 appears to have been a disaster for gm wiring

Ok, what lead? There's no extra wire to plug in anywhere else, even if you did know where to plug it in.

Imho, '77 was the bastard year for wiring. It was a one-year-only delay wiper switch and delay box.

 

[gmachinz]

I have to agree that ‘77 was the only goofy year for them. I have refurbished a few of the delay modules and on a couple I suspect a bad IC chip so....I am waiting on my Motorola replacements to arrive so I can solder them in and re-test. These modules can be a little pita at times lol

 

[TubeTruck]

Gonna hijack this real quick. Does anyone know where to get good delay boxes? Rockauto sells the switches and they did have the delay boxes at one time recently but I can't find then anymore, and I hear AC Delco stopped making them. I really don't want to get one of those Chinese ones.

 

[Rob P]

For '78-'83 trucks, it's just a matter of plugging in the delay box and wiper switch to the existing pigtail in the dash. Sounds like a bum switch or box.

Well we tried three boxes now, the last coming out or a truck where they were working when removed. I had an electronics guy check one of the boxes I tried and he could find nothing wrong with it. A manual for 78 very specifically says a lead plugs into the acc port on the fuse box. I have no trouble splicing in a wire, I just need to know which color to splice in to.

 

[TubeTruck]

For about $550 you can have delay wipers from Detroit Speed lol

https://www.detroitspeed.com/1973-1983-c10-electrical

 

[TubeTruck]

Well we tried three boxes now, the last coming out or a truck where they were working when removed. I had an electronics guy check one of the boxes I tried and he could find nothing wrong with it. A manual for 78 very specifically says a lead plugs into the acc port on the fuse box. I have no trouble splicing in a wire, I just need to know which color to splice in to.

Just found this. Hope it helps

You must be registered for see images attach

 

[Rob P]

I have to agree that ‘77 was the only goofy year for them. I have refurbished a few of the delay modules and on a couple I suspect a bad IC chip so....I am waiting on my Motorola replacements to arrive so I can solder them in and re-test. These modules can be a little pita at times lol

What color wire gets the

Just found this. Hope it helps

You must be registered for see images attach

Looks like the pink wire gets spliced in to and then into the red wire to the box, which will feed power to the delay circuit. We have a winner! thanks!

 

[bucket]

The pink wire is on the ground side of the washer motor.