Thread: 65 C 10 electrical question

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OK.. me again... no one 'fessed up to having an electrical diagram for a 65 C 10, but maybe one of ya knows the answer to a specific question:

There has been a lot of 'hack' wiring on this truck but I seem to have traced out that the brake circuit:

comes from the fuse box ( orange wire ) to the headlight switch, where it jumpers off the terminal, and goes to the brake switch ( this wire was burned up ). The other side of the brake switch ( white wire ) goes right back to the light switch. Is this right?

I had the brakes working, then they suddenly quit, along with the tail lights. I started trouble shooting, and they suddenly started working again. Then, I traced the wire back to the headlight switch, and saw the plug on the back of the switch had melted some ( probably when the orange wire burned up ). Unplugged / replugged the switch and they stopped working again, and won't go back to working no matter how many times I unplug/ replug the switch.

So.. I'm not sure if the switch or the plug is the problem. any suggestions?

Originally posted by firebird77clone
OK.. me again... no one 'fessed up to having an electrical diagram for a 65 C 10, but maybe one of ya knows the answer to a specific question:

There has been a lot of 'hack' wiring on this truck but I seem to have traced out that the brake circuit:

comes from the fuse box ( orange wire ) to the headlight switch, where it jumpers off the terminal, and goes to the brake switch ( this wire was burned up ). The other side of the brake switch ( white wire ) goes right back to the light switch. Is this right?

I had the brakes working, then they suddenly quit, along with the tail lights. I started trouble shooting, and they suddenly started working again. Then, I traced the wire back to the headlight switch, and saw the plug on the back of the switch had melted some ( probably when the orange wire burned up ). Unplugged / replugged the switch and they stopped working again, and won't go back to working no matter how many times I unplug/ replug the switch.

So.. I'm not sure if the switch or the plug is the problem. any suggestions?

if you have turn singles then the white wire should be going into your steering colum to the turn signal sw.

Thanks... I re-traced the wires, and sure enough it does. Must have mis-traced.

I'm past the brake light problem. Now I am focusing on dash lights. Any more good tips?

Originally posted by firebird77clone
Thanks... I re-traced the wires, and sure enough it does. Must have mis-traced.

I'm past the brake light problem. Now I am focusing on dash lights. Any more good tips?

you sound supprised. i can rewire the turn signal sw without a diagram. dont forget about the dimmer sw.

naw, not surprised at all. ( grateful for any little bit )

Trying to remember what I traced out today.. the dimmer had two wires, one went to the fuse box, the other went to the dash connector, and to the little bulb in the prnd1. the 'hot' side of the fuse box went out across the wire harness, and I suspect it goes to the firewall connector ( pass side ) with the temp sensor and the starter wires.

Speaking of the starter wires... seems I recall that a chevy starter has one wire to the start solenoid, and two wires on the other lug of the starter. The two other wires were for bypassing the coil resistor during start?

Of the starter wires.. the purple seems to be for the start solenoid, I have also a yellow, and a dark colored wire with hi-temp insulation, and the two sensor wires. Don' suppose you know ( exactly ) what they all do?

Thanks again.

I have the wiring diagram book for those year trucks and ya got me curious enough about the brakelight wire that I'm goin to dig the book out first thing tomorrow. I believe that the brakelight is powered at the fuseblock and then goes to the T/S switch, but I could be wrong. As for the wires on the starter solenoid, the purple is the start wire. The wire on the other small post goes to the positive post on the coil to bypass the ballast resistor while crankin the engine. Any wires on the large post with the battery cable are simply power supply wires for various systems and accesories.

THANKS

any way you could scan it and email it to me?

Originally posted by firebird77clone
naw, not surprised at all. ( grateful for any little bit )

Trying to remember what I traced out today.. the dimmer had two wires, one went to the fuse box, the other went to the dash connector, and to the little bulb in the prnd1. the 'hot' side of the fuse box went out across the wire harness, and I suspect it goes to the firewall connector ( pass side ) with the temp sensor and the starter wires.

Speaking of the starter wires... seems I recall that a chevy starter has one wire to the start solenoid, and two wires on the other lug of the starter. The two other wires were for bypassing the coil resistor during start?

Of the starter wires.. the purple seems to be for the start solenoid, I have also a yellow, and a dark colored wire with hi-temp insulation, and the two sensor wires. Don' suppose you know ( exactly ) what they all do?

Thanks again.

it dont matter where the brake wire comes from as long as its fused and goes in to the turn signal sw. at the right place. the dimmer has 3 wires. one from the head light sw. and one to hi beam ad one to low beam. dont know color, might be LG-hi beam, T-low beam, LBL to head light sw.

you are right on the starter. yellow should be the coil by-pass wire, purple to the "S" on the sol. if the other wires has big ends on them they should go on the big starter bolt, for acc. voltage inside the car.

the connectors are long gone.

it hadn't occured to me to check the hibeam switch. Probably a good idea... heh heh.. just so much else to look at, it's a real mess. The running lights and tail lights are working though, and headlights do come on.

I am starting to think the power for the dash lights sources from the afore mentioned starter wires. I suspect the wire with the hi temp insulation should go on the large terminal for power feed.

I have my 64 C 10 to compare to, but it is a little screwy too.. but everything works on it. Tried to get up there and see what goes where, but the headers are making it hard to see. Looks like I actually have FOUR wires going to my starter.. on my truck I am using the old ignition wire to switch a couple relays for the HEI and the fuel pump, and the fan. No idea what the fourth wire is but everything seems to work....

k.. here is what I found... the orange wire supplies the power to the light switch. The brown wire sends power to the tail lights. The green wire sends power to fuse, then a gray wire sends it to the dash lights..

dam things ( dash lights ) are working now.. dunno why.. think the dam headlight switch is flaky... dunno, gotta check the horn circuit next...

The dashlights are dimmed by rotating the headlight switch knob when it is pulled either halfway or all the way out. Rotate clockwise to dim, counterclockwise to brighten UNTIL it hits a clickstop, the if you rotate it further counterclockwise past the detent, you turn on the domelights. If you need to replace the switch, you will need to release the stem with the knob on it. This is accomplished by pulling the knob all the way out. While pressing the little spring-loaded button on the opposite side of the switch from the harness plug, push the knob slightly in to release, and then pull it free. The dimmer coil for the dashlights is external on the end of the switch nearest the dashboard, and it becomes dirty and corroded over time. If you rotate the knob slightly and the dash lights cut out, this could be the problem.

A lot of the melted and missing plugs are available at Napa and really should be installed. Most good auto parts stores (Napa or commercial grade stores) should have the loose female blade terminals with the lock tangs that go in the stock plugs so you can install the correct color and gauge wire ( they'll have these in compartment boxes in the back usually, so you'll hafta ask!). It's best for wires to run their full length without splices and soldering and shrink tubing are the best way to splice wires or attach ends (after crimping)
I was going to try to send you the 65 wiring schematic I have, but it's actually a booklet that requires you to match up the different systems on different pages. Getting one of these booklets for your truck is the best $5 you'll spend to correct hacked wiring. It even tells wire colors and gauges. Get it from LMC truck

Get the wiring diagram,but remember you need several circuits that won't be in there. You also have a voltage relay which sends power half the way around the engine compartment and also hooks to the horn relay. You're probably going to used a newer alternator which needs less circuits,HEI,which needs a heavier gauge non resister circuit,electric fan etc. It pays to buy the factory type wire ends and the special crimp tool for them. This way llthese extra circuits can be inclued in a harness abnd run through the dash connecter with no extra holes drilled. Hank

thanks lots for all. I got it all straightened out.

I'm an electronics technician by trade, and would rather troubleshoot a poorly engineered industrial circuit than try to straighten out a car after it has been hacked...

All connections were soldered and taped, and even put a layer of shrink over the tape, till i ran out of shrink. After that, a couple drops of superglue on the end of the tape wrap makes sure it won't come unravelled. ( I also do a second wrap... that way the second wrap would have to completely unravel before the first layer could )

I think I pulled out at least 20 feet of wire: everything was straight wired directly from the battery, with toggle switches. I am amazed that the whole thing didn't go up in smoke.

Again, thanks for all the replies.

EG

A wire tie on the end of the tape will accomplish the same result and you don't have to worry about the super glue breaking down.