Help! 1965 corvette

[FRED BAUER]

I am working on a 1965 corvette , can anyone tell me where the power for the headlights comes from that goes to the headlight switch?
I have power to the park lights but bot headlights, Thanks Fred

 

[car-nuts]

Looking at the diagram for my '63, it is difficult to trace headlight and headlight switch power to it's source.

Here's how it appears to me...

There are 2 wire bundles/connectors into the large firewall connector on the firewall above the steering column; each connector has 4 pairs of stacked contacts (ie, 4 high by 2 wide).

Power to the headlight switch appears to come from the battery via a blue wire coming from the battery terminal on the starter solenoid, through the firewall connector set (of 4 stacked pairs) closest to the center of the firewall, specifically the top contact on the fender side of that pair; power then goes from the headlight switch to the dimmer switch via a lt blue wire.
Since your parking lights work, the path from the battery to the headlight switch is apparently fine.

From the dimmer switch, power flows to the headlights, parking lights, headlight motors, etc. through the firewall connector set closest to the fender.

- Do the headlight motors work?
- Have you checked to see if the headlights work in either high or low beams?
(dimmer switches can fail)

Power to the headlights and parking lights flows through that firewall connector closest to the driver fender, via the two middle rows/pairs of contacts. The power for headlights specifically, flows through the contact closest to the fender in the pair of contacts above the bottom pair, and through the contact furthest from the fender in the pair of contacts above that (second row/pair down in the connector)... one is for high beams and one for low beams, I'm not sure which is which (see diagram below).

Those firewall connectors, of course, are a frequent source of corrosion problems interrupting power. Since the parking lights work, you should probably concentrate your troubleshooting on the dimmer switch and on the firewall connector set of contacts closest to the fender, specifically the 2 contacts I mentioned at the end of the prior paragraph.
Looking at the connector contacts from the engine side:

X X
O X
X O
X X

 

[FRED BAUER]

C2 headlights

Looks like you have given me a great deal of information.
The headlight motors work. but I will start with the dimmer switch , 7 then check the plugs at the fire wall.Silly how I did not even think to check the dimmer switch. Thanks very much Fred

 

[Toms007]

Wow, it's not often that I get to WELCOME 2 new members at the same time. Funny how you both found one another, but I will say we have some of the best C1 and C2 guys in the country here at CAC. I'm pretty sure that one of them will be by soon to add to what you've already put out here.

 

[FRED BAUER]

C2 headlights

Looks like you have given me a great deal of information.
The headlight motors work. but I will start with the dimmer switch , 7 then check the plugs at the fire wall.Silly how I did not even think to check the dimmer switch. Thanks very much Fred

I do not have a blue wire from thr battery , They are Red & black. The plug going into the firewall from battery has 4 live terminals , 1 groumd terminal & 3 neutral terminals.
I do not have any power at the fuses , eater side ,below the top 3 witch get energized from the key switch.
Possibly they should be energized from the plug coming from the battery?
Or ma by i should remove fuse panel to see if it is oxidized.
I have tried cleaning both plugs & used contact Greece on the terminals

 

[Tom Bryant]

Welcome to both of you

It sounds like you are on the right track. Good luck.

Tom

 

[car-nuts]

I agree, sounds like you are on the right track. By black & red wires, do you mean the thick battery terminal cables? The red battery cable goes to the starter solenoid. There are then multiple positive power wires from the starter solenoid... two of those are feed wires to the car's electrical system; one goes to the firewall connector furthest from the fender, and the second to the horn relay, and both then branch to many places.

The diagram I was looking at for my prior posting is for my '63.
It may not be the same as for your '65, and it's certainly possible the wire colors are different.

Here are links to the two halves of an electrical diagram for a '65:

http://www.oldcarmanualproject.com/...ng diagrams/Chevrolet/MWireChev64_3WD-106.jpg

http://www.oldcarmanualproject.com/...ng diagrams/Chevrolet/MWireChev65_3WD-107.jpg

You may find it best to print the diagrams and use different-colored highlighting magic markers to trace circuits to identify the wire colors and connectors. If you don't have the computer skills to create jpg files from them and blow them up to a usable size, email me and I'll send you enlarged copies.

First thing I would check is whether the headlights work in either low or high beam. Also, I think there is a "headlights on"
indicator light somewhere on the instrument panel, as well as a "high beams on" indicator light. If the indicator lights work but the headlights don't, then power is getting to the hi/lo-beam switch but power is not getting through the firewall connector (the one closest to the fender) to the headlights via a tan wire (low beams) or a black w/lt green stripe wire (high beams). If the indicator lights aren't working either, then the problem may be in the fuseblock on the firewall.

It appears to me that power is supplied to the hi/lo beam selector switch via a black wire with a light blue tracer, so with the headlight switch on, I'd look to see if power is getting through that Blk-Lt Blue wire to its connector (receptacle) at the hi/lo beam switch. If so, then jumper that connector to one of the other connector receptacles and see if that powers the high or low beams at the headlights, then try jumpering to the second connector and check again; if either (or neither) works (lights the hi beams or the low beams), it's then a matter of finding out where the path(s) to the headlight connector is broken (tan wire (low beams) and/or a black w/lt green stripe wire (high beams)).

I used the '65 diagrams for the 2 paragraphs above... I'll try to take a closer look at the '65 diagrams when I have some time. But, it sounds as though you are finding and correcting some pertinent problems.

Good luck, following the wiring and checking continuity through those firewall connectors looks like a daunting task.

 

[Glide]

I agree, sounds like you are on the right track. By black & red wires, do you mean the thick battery terminal cables? The red battery cable goes to the starter solenoid. There are then multiple positive power wires from the starter solenoid... two of those are feed wires to the car's electrical system; one goes to the firewall connector furthest from the fender, and the second to the horn relay, and both then branch to many places.

The diagram I was looking at for my prior posting is for my '63.
It may not be the same as for your '65, and it's certainly possible the wire colors are different.

Here are links to the two halves of an electrical diagram for a '65:

http://www.oldcarmanualproject.com/...ng diagrams/Chevrolet/MWireChev64_3WD-106.jpg

http://www.oldcarmanualproject.com/...ng diagrams/Chevrolet/MWireChev65_3WD-107.jpg

You may find it best to print the diagrams and use different-colored highlighting magic markers to trace circuits to identify the wire colors and connectors. If you don't have the computer skills to create jpg files from them and blow them up to a usable size, email me and I'll send you enlarged copies.

First thing I would check is whether the headlights work in either low or high beam. Also, I think there is a "headlights on"
indicator light somewhere on the instrument panel, as well as a "high beams on" indicator light. If the indicator lights work but the headlights don't, then power is getting to the hi/lo-beam switch but power is not getting through the firewall connector (the one closest to the fender) to the headlights via a tan wire (low beams) or a black w/lt green stripe wire (high beams). If the indicator lights aren't working either, then the problem may be in the fuseblock on the firewall.

It appears to me that power is supplied to the hi/lo beam selector switch via a black wire with a light blue tracer, so with the headlight switch on, I'd look to see if power is getting through that Blk-Lt Blue wire to its connector (receptacle) at the hi/lo beam switch. If so, then jumper that connector to one of the other connector receptacles and see if that powers the high or low beams at the headlights, then try jumpering to the second connector and check again; if either (or neither) works (lights the hi beams or the low beams), it's then a matter of finding out where the path(s) to the headlight connector is broken (tan wire (low beams) and/or a black w/lt green stripe wire (high beams)).

I used the '65 diagrams for the 2 paragraphs above... I'll try to take a closer look at the '65 diagrams when I have some time. But, it sounds as though you are finding and correcting some pertinent problems.

Good luck, following the wiring and checking continuity through those firewall connectors looks like a daunting task.

Thanks for the information! Just got my 66 going today, but as I prepared to head out to my first 'cruise in' of the year found my headlights wouldn't light up (although they pop up). I'm too tired tonight but I will go over these things tomorrow.