Topic: wires to nowhere
in Forum: C3 Electrical
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Thanks to everyone for the welcome. I thought I was a pretty sharp guy but this rebuild is a humbling experience. I have both the Chiltons and Haynes books but I have learned not to trust them. I got the wiring diagrams from "Adams Apple" which cured some problems immediately but I still have some questions if anyone can help.
#1. I have a small pink wire in the conduit at the firewall that contains the distributor and wiper wiring. Wiring diagram shows a small pink wire for intermitten wipers. I dont think I have intermitten wipers as there are no connections on the wiper motor for this wire. Did GM use the same harness for both? Is this just a usless wire?
#2 Pink again at the under dash end of my cruise control harness I have an extra connector right at the fuse panel. Tee's off of the connector wire plugged into the fuse. Is this just a different connector for a different model??
#3 I have a capacitor on my intake that I believe is for radio interference. One wire is broken and missing which I can repair, the other is not connected. Chiltons shows this capacitor going through the large pink distributor wire. The connectors seem to fit the tach wire better. My new wiring diagram doesnt show the capacitor at all. If I only had another car to look at this would be so simple.
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For no 1...the pink wire should be for the 'wash' function for the wipers. there's an additional pink lead for the wash with delay wipers. Look at your fuse panel and see if you have a fuse in the wiper spot or a small circuit board. The circuit board WILL be down there but it's only plugged in if you do have the delay wipers. Kinda Bubba for a factory setup.
mkapp7879 2008-08-31 21:01:30
No 2...I'll take a look at mine and see if I can determine anything. There IS a pink wire that provides power to the cruise.
No 3...that capaciter is a tach filter. It should be in line with the wire from the distributer to the tach. Tach will work without it but it should be used.
A great manual for working on your 78 is the GM Corvette Shop Manual for the 1979 model. That manual is ALL Corvette, unlike the 78 edition. MOST things are the same except the fuse panel and a few other items, but the wiring section is 140 pages with very good color diagrams. This is the book with the red cover. I rarely use my 78 unless it's to double check.
Had this on file, may help. Note the board in the wiper slot...
Lifetime MemberMany cars install wires that are not used when the option is not there. It's easier and cheaper than making two different harnesses.
OK, no. 1 again....on my 78SA the wiper motor had a short 6"pigtail with a connector coming out of the plastic cover on the driver side, pink. The pink wire coming out of the conduit connects to that connector. But I have delay wipers.
No 2...I see 2 pink wires under the dash. The one plugged into the fuse box and the other is for the cruise release switch attached to the brake pedal linkage. That one shares a connector with a red wire.
Like Ken said, there will be unused wires around. Did you see the little wiper circuit board tucked up out of the way? And I know my 79 4speed has a lamp holder under the console for the auto selector. Not many unused wires in any of mine, tho, as they're all loaded!
I cant thank you enough for your help mkapp. Its such a pain (literally) to get a good view under the dash. I dont have the small circuit board or the pigtail for delay wipers so Im going to assume the extra pink wire at the firewall is not to be used. I have the same set up as you under the dash for the cruise except I still have an extra connector. I had to replace the vacuum line and repair the cruise wiring harness going through the fire wall. Maybe when I unwrapped the tape I uncovered the extra connector. here is a link to a good look at the harness http://www.lectriclimited.com/corvette-catalog-pdf/78.pdf
you can see that it appears that there are 2 connectors at the end of the single pink wire. One plugs into the fuse box, the other is exposed in my situation. If you dont see this extra connector, it must be concealed in your harness.
Two connectors at the SAME end? Or opposite ends? You're saying you DO HAVE that pink connector that's plugged into the center of the fuse panel, the ign outlet? The other end would go to the headlight on warning buzzer, which is part of the "convenience group" that I don't believe you have. Delay wipers are part of that option and you don't have that.
mkapp7879 2008-09-01 17:27:30
You don't even have that little wiper board tucked up into the jumble of wires?
I have 2 connectors on the same end of the same wire of my cruise control wiring harness. you can see them both in the pic of the harness if you go to the link I sent. You are right about the "convience group" I dont have the headlight on warning buzzer or delay wipers. I am only talking about the cruise control harness.
Can't open the link. Looking at the skematic in the 78 shop manual, I only see one pink wire(labeled as red). Comes out of the fuse panel(or ignition somewhere?) and goes to the cruise release switch at the brake pedal. Mine under my dash then changes to red and according to the diagram goes to the engagement switch, with the connectors at the steering column. No more red or pink after that.
mkapp7879 2008-09-01 18:35:34
Stuck my camera up under the dash and clicked wildly. Nothing helpfull.
Here's the skematic from the 78 manual...
Just another bit of information.
GM typically uses consistant color codes for certain types of things.
Red is usually a constant battery hot.
Pink is a hot with the ignition key turned on.
in Forum: C3 Electrical
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