Hi Guys-
I have a 88 iroc that I just finished. The car sat a long time. I replaced the headlight switch in thoughts that’s why I had no gauge lights. Turns out every single bulb had bad connections. Headlights work fine 95% of the time. I had it out last week at night and was almost home when the headlights started cutting in and out. Pulled the switch back and forth a few times, made no difference. Gauge lights stayed on the whole time (not sure of the tailights..was kind of scary) which makes me think it’s not an issue with the switch. Any thoughts?

 

Sounds like it could be a voltage issue. What are the conditions of the battery, battery cables, alternator?

 

The reason your lights were doing the on/off thing is because there is a self resetting circuit breaker built into your headlight switch, and something is causing your headlights to draw too much power.

Are your headlights stock types, or are they high wattage aftermarket ones?

 

Here's a diagram showing why only your headlights blinked, and not your taillights. looking at the headlight switch see where at the top left there are two dots with a curved line instead of just a straight line (wire)? That symbol represents the circuit breaker and it feeds power to the headlights only. The taillights (and dash lights) get their power from the taillight fuse shown at the top middle of the switch.

 

They’re just stock sealed beams.

 

Well that rules out the bulbs themselves drawing too much power, but something is loading the circuit beyond the breaker's limit. A partial or intermittent short where a wire has chafed and is touching the body somewhere perhaps....

 

Years ago, while driving a 3 ton Ford truck, the same happened to me. I knew that Ford, maybe other brands) had a solution, at least short term. I turned the headlights off for about a minute, then turned them back on and all was well for the remaining 100 miles. It was just a rare intermittent problem. Never happened again.

 

Multiple/ many lose or poor Connections for the Light-Bulbs can add up to Over-Heat the Headlamp-Switch.

The Circuit is not like a Modern Vehicle...
The Headlamp-Switch carries the Load of the Circuits that run through it.

As OrangeBird correctly mentioned, the Headlamp-Switch contains it's own Bi-Metal Strip (Circuit-Breaker) Heat-Switch.
It is the same with the Power Window Motors.

I do a ton of New/ Modern Power-Distribution Systems (and Wiring-Harnesses) for Our Vehicles...
I usually will create a New Set of Exterior Lighting Harnesses that are powered by Relays in a Bussed Electrical Center
(removing the Load from the Headlamp-Switch).

 

You know something I just thought of here? There IS one possibility we hadn't considered. Husky83 said he replaced the headlight switch because he thought it was causing his gauge light malfunction(which it turns out it wasn't), and we never asked; Had the headlights ever cut in and out with the original switch? Because if not, perhaps there is nothing wrong with his wiring at all and the real problem resides in the new switch having a defective breaker that trips at a slightly too low of current than it's supposed to? It's not like we've never seen brand new parts right outta the box be defective, right? (Insert the standard rant about offshore manufacturing here ) .

So my suggestion to Husky83 here would be that if ya still got the original switch put it back and see if the flashing stops....

 

Thanks for all the advice guys. Quick run down on the car.. I bought it as a roller, no engine/trans. Car was clean and straight so I found a parts car for the roller that had all the misc f body drivetrain parts needed. Bought a 383 crate engine and jegs 700r4. This thing had obviously sat for quite a while. Put the headlight switch in as I said bc I thought that was why I had no gauge lights. The switch came from Napa so I figured it was probably better than a Autozone one. The twist dimmer didn’t seem right on the old one. It was functional however (as much as I used it…which was literally enough to start the car and pull it out of our shop before our work day). It never had to function for more than a minute or 2. The strange part of the light issue I’m having is there is no rhyme or reason. The last time I had it out, it was completely fine for a good 45 minutes of driving. And then all of a sudden it started acting up.

 

That Dimmer Design pretty much always ends up with Dead-Spots.