[C2] Headlight Issue
#1
Le Mans Master
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Headlight Issue
Here’s an interesting issue. Last night I had to go out in my 1964. I turned the headlights on and in about 30 seconds they flickered and went out. If I turned them off, waited a few seconds and turned them back on, same thing.
So, typically this is the headlight switch circuit breaker. Thing is, my tail lights weren’t working and I traced it to a short in one of the tail lights caused by the wrong bulb jammed into the socket grounding the circuit. That would blow the fuse so someone put a larger fuse in. That also blew, but burned up the tail light power pin on the headlight switch, so I just replaced the switch last week. I then took it in for state inspection and it passed. My wiring harness was also replaced about 10k miles ago. In fairness, I haven’t had a chance to troubleshoot it, yet, but I was wondering if there are any other Corvette unique potential issues that could cause this that might save me some time. Thoughts?
So, typically this is the headlight switch circuit breaker. Thing is, my tail lights weren’t working and I traced it to a short in one of the tail lights caused by the wrong bulb jammed into the socket grounding the circuit. That would blow the fuse so someone put a larger fuse in. That also blew, but burned up the tail light power pin on the headlight switch, so I just replaced the switch last week. I then took it in for state inspection and it passed. My wiring harness was also replaced about 10k miles ago. In fairness, I haven’t had a chance to troubleshoot it, yet, but I was wondering if there are any other Corvette unique potential issues that could cause this that might save me some time. Thoughts?
#2
Team Owner
If you used a repro headlight switch they are pretty prone to this problem...they just don't handle the current load that the originals did (do). You can try to find an original/NOS or put relays in to take the load off the repro switch...
If you're a bit handy with crimping tools you can add the relays off the dimmer switch circuit without butchering existing wiring... Mad Electric offers a kt as so other vendors or you can "roll your own" with Radio Shack parts...
If you're a bit handy with crimping tools you can add the relays off the dimmer switch circuit without butchering existing wiring... Mad Electric offers a kt as so other vendors or you can "roll your own" with Radio Shack parts...
Last edited by Frankie the Fink; 10-15-2018 at 09:39 AM.
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Factoid (10-15-2018)
#3
Team Owner
If it's the circuit breaker, the lights will come on and go off, then repeat over and over. It will typically do it more on bright than dim, unless a short has occurred somewhere. If the headlights flicker and go off and stay, I'd be suspicious of the floor dimmer switch. When it happens, switch the dimmer and see if it brings them back. If so, it's a cheap and easy fix. Dimmer's are available at local auto parts stores and replaced with two screws and a connector.
A very likely cause, specially if this issue just started, is the aftermarket headlight switch you bought has a weak circuit breaker. That would be very typical of the replacement headlight switches.
A very likely cause, specially if this issue just started, is the aftermarket headlight switch you bought has a weak circuit breaker. That would be very typical of the replacement headlight switches.
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Factoid (10-15-2018)
#4
Le Mans Master
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If it's the circuit breaker, the lights will come on and go off, then repeat over and over. It will typically do it more on bright than dim, unless a short has occurred somewhere.
A very likely cause, specially if this issue just started, is the aftermarket headlight switch you bought has a weak circuit breaker. That would be very typical of the replacement headlight switches.
A very likely cause, specially if this issue just started, is the aftermarket headlight switch you bought has a weak circuit breaker. That would be very typical of the replacement headlight switches.
Thank you both, I know exactly where to start.
#5
Le Mans Master
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Drew up a schematic and ordered a couple relays and a circuit breaker. I’m going to split the feeds in the bundle that runs across the driver side inner wheel well. When I’m done, it should blend right in.
Frankie, I plan on taking my 12v feed off the load side of the horn relay. This will preserve my ammeter accuracy, correct?
i added the schematic to the wiring diagram in my 1964 shop manual supplement.
Frankie, I plan on taking my 12v feed off the load side of the horn relay. This will preserve my ammeter accuracy, correct?
i added the schematic to the wiring diagram in my 1964 shop manual supplement.
#6
Team Owner
Drew up a schematic and ordered a couple relays and a circuit breaker. I’m going to split the feeds in the bundle that runs across the driver side inner wheel well. When I’m done, it should blend right in.
Frankie, I plan on taking my 12v feed off the load side of the horn relay. This will preserve my ammeter accuracy, correct?
i added the schematic to the wiring diagram in my 1964 shop manual supplement.
Frankie, I plan on taking my 12v feed off the load side of the horn relay. This will preserve my ammeter accuracy, correct?
i added the schematic to the wiring diagram in my 1964 shop manual supplement.
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Factoid (10-16-2018)
#8
Le Mans Master
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Thanks, buns, just ordered the connectors!
#9
Le Mans Master
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The connectors showed up and I built my harness. The three connectors plugged into the stock harness, the relay bank and circuit breaker attached to the inner fender, and the red and black wires to the horn relay (via the CB) and ground respectively. Everything now works perfectly and I swear the headlights are brighter!
Of course the wife wasn’t happy with the wire harness on her kitchen counter, but I call that collateral damage!
Of course the wife wasn’t happy with the wire harness on her kitchen counter, but I call that collateral damage!
#10
Le Mans Master
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Since I’ve had several questions, I thought I would update this thread and answer the most common questions.
The connectors I’ve marked on this ‘64 wiring diagram are the two that are disconnected. The headlight wiring harness is only used to control the relays. The blue highlighted connector from the bulkhead connector plugs into the new harness I made below and the two red connectors plug into the pigtails that go to the headlights.
The blue connector is the control from the bulkhead connector and the two red are the connectors for the headlight pigtails. If your engine bay headlight harness runs down the passenger side, mount the relays on the passenger side, run the two red wires to the circuit breaker and then to the horn relay and the black wire to ground or driver side if on the driver side.
The connectors I’ve marked on this ‘64 wiring diagram are the two that are disconnected. The headlight wiring harness is only used to control the relays. The blue highlighted connector from the bulkhead connector plugs into the new harness I made below and the two red connectors plug into the pigtails that go to the headlights.
The blue connector is the control from the bulkhead connector and the two red are the connectors for the headlight pigtails. If your engine bay headlight harness runs down the passenger side, mount the relays on the passenger side, run the two red wires to the circuit breaker and then to the horn relay and the black wire to ground or driver side if on the driver side.
Last edited by Factoid; 02-07-2021 at 05:19 PM.