A friend has a 66 Corvette convertible with powerglide that he replaced the underhood wiring harness and dash wiring harness with Electric Limited supplied wiring harness. Problem is that when the ignition switch is turned to either the accessory or run position the dash lights and tail lamps come on. He has completely removed the electrical tape from the dash wiring harness looking for the problem. Any ideas or suggestions?
C2 1966
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Re: C2 1966
Thats a tough one....
I'd start by disconnecting the light switch and turning on the ignition.
If the problem goes away... replace the light switch. (Not likely though)
Looking at the schematic, one place that might cause the problem is on the back of the fuse block. If the #12 brn wire (coming from the ignition switch) were interchanged or shorted with the #16 Dark Green wire (coming from the light switch) then the ignition switch would supply voltage to the dash lights #20 grey wire and possibly the tail lights thru the light switch.....
A test here would be to remove the fuse for the instrument lights. If they don't come on with the ignition then your problem is BEFORE the fuse on the schematic...which could be the above mentioned wiring.
Good luck.- Top
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Re: C2 1966
Another test would be to remove the fuses, disconnect the battery and test the continuity between the inputs to the fuses. REFER TO SCHEMATIC!!!. With everything off there should be no continuity between fuses as shown except those that are tied together with a bar.... (I believe the left side of the fuse is the input side)
Starting from the top, Fuse #2 & #3 are tied as well as #5 & #6......
If fuses #3 & #4 show continuity you've found your problem.- Top
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Re: C2 1966
Jim,
Unfortunately it's not uncommon for the wiring harness to have one or more wires incorrect. The harness I got from Electric Limited had the wires mixed that go to the headlights and I had to redo them. Have you contacted them yet?...maybe they have an idea how to troubleshoot the problem with the least amount of effort.- Top
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Re: C2 1966
Thank you both for yours suggestions. I will pass the information to my friend. He has contacted Lectric Limited and has removed the instrument cluster twice after the installation of the dash wiring harness to find the problem. Perhaps with these suggestions he will discover the problem.- Top
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Re: C2 1966
Glad I could be of help. He probably can fix it himself. After removing the harness and the fuse block from the car, inspect the backside for the wiring error and rewire per the schematic. Maybe its as simple as some wiring being pinched.- Top
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Re: C2 1966
Update on my friends 66 convetible PG with the replaced wiring. He spent many hours reinstalling the new underdash wiring harness. He fixed the problem by cutting one gray wire that is in the connector that has black, gray, and yellow wires for the radio. He said his original harness had this same gray wire disconnected to the radio connector. He said he could live without a lighted radio dial. Said to give thanks to the person who supplied the fuse block information.- Top
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Re: C2 1966 Radio wiring
Jim,
I was the guy pointing your friend toward the fuse block. After this post by you, concerning the radio grey wire (dash Light circuit) I'll bet his problem with the dash and tail lights coming on with the key, would have gone away if he would have turned the radio off.
His real problem is in the switch/circuitry of the radio on/off or a shorted grey wire to the yellow wire in that circuit, OR an incorrect replacement on/off switch in the radio.
Here is how its should work:
1) Key off, Dash Lights off, Radio off, radio dial light off.
2) Key on, dash lights off, radio off, radio dial light off.
3) Key on, dash lights off, radio on, radio dial light off.
4) Key on, dash lights on, radio off, radio dial light off.
5) Key on, dash lights on, radio on, radio dial light on.
Check it out by watching the voltage on the grey wire, that is still connected to the radio, using the above table of circumstances.
The grey wire (dash lights) should be connected to the radio if all other things are correct.- Top
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Adendum
The voltage was feeding backward from the yellow wire to the grey wire either thru a switch malfunction or incorrectly wired switch or a short in the connector between the yellow and grey wires.- Top
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