Help! RFI: I'm stupid - where's the headlight breaker/fuse on a '75?

[WayneLBurnham]

After a series of alternator malfunctions on my highly modified - I only have the "no headlight option" still eneabled. I pulled the breaker on the panel and got a new one, only to find out "Acc" means "Power Windows".

When my dysfunctional alternator hit 19V the other day it popped the headlights (the brights were on also.)

Now, after a few days of stupidly trying to put together one decent 80+ amp one-wire alternator out of three parts, I found a cheapy at NAPA for 70ish amps until my replacement aftermarket 140 -200A returns.

Now that that fire is out, does anyone know just where they hid the relay or breaker to the headlights? I found the breaker for the windows - that's not it.

'Preciate any input!

 

[petes74ttop]

Where's it at?

On my 74 it's just to the right of the emissions sticker. It has one large red wite on each terminal.PG

 

[wishuwerehere82]

Courtesy of JohnZ:

"There's no fuse for the headlights - that circuit is protected by a self-resetting thermal circuit breaker that's internal to the headlight switch. With your other lighting issues, sounds like you need a new switch."

That was in reference to a 79 Vette.
I am going to pass it along to you.

 

[petes74ttop]

Courtesy of JohnZ:

"There's no fuse for the headlights - that circuit is protected by a self-resetting thermal circuit breaker that's internal to the headlight switch. With your other lighting issues, sounds like you need a new switch."

That was in reference to a 79 Vette.
I am going to pass it along to you.

You are correct, the CB next to the sticker is for the power windows.
Sorry about the misinformation, my bad! PG.

 

[WayneLBurnham]

IT turns out I really *DID* blow all four headlights at once

I posted RFI's nearly simultaneously at two 'vette sites, and CAC responded with the most detail, so I'll put the original here first.

The wiring and switch are intact...after pulling and testing all four headlights, I really *did* blow all four bulbs at the same instant, as the beastie passed 19V or so. All other systems, mainly having been altered by me seem really capable of taking aircraft voltage as I specced, but I never redid the main headlights to HID or something like that. (The fuel pump was interesting though - had to dial the regulator way down or I got 12 psi.)

You can bet, shortly after I get the vacuum pump system on line, I *will* be correcting this absurd design defect and the headlights will be fed through two 40-50A breakers like the fan array is now, relayed to a main source like the starter or the alternator power stud, and the switch will only handle the minimal voltage.

Really, after seeing (again) the mess the fuse box is when I pulled and changed the window breaker, I should go ahead and redo the main fuse box too (it's been 33 years.)

That reminds me - how many others have eliminated the window relays and route main power through the switches? I wondered why they burn out so quickly when I found what had once been the window relays near the dash, disconnected and unused since long before I was inflicted on this poor mutant car. ....another upgrade (this time return to original design) I have to do sometime....

...after the vacuum pump and new valve cover, t/c and oil pan gaskets, the new Gear Vendors speed sender and control boxes and the QA-1/Carerras up front to match the back....I really hate no overdrive....