Electrical: 1955 conestoga wagon headlights popping fuse

[keithwahl]

Can someone refer me to the wiring diagram and give me some pointers to trouble shoot my headlights
Headlights and dash lights work when i put in the new 30 amp fuse
when I turn on engine (this is a 289 car with blower) seems like fuse pops
Any thoughts here on how to trouble shoot
I think my switches are ok
Turn signals all work as do rear lights
thanks Keith

[bezhawk]

There should not be any fuses in the headlight system. They are supposed to be circuit breakers. Perhaps the tail lights is what's blowing THAT circuit? Is this aftermarket wiring? Something is grounding out to blow a 30 amp fuse as soon as you turn it on.

[StudeRich]

If starting the Engine blows the Fuse, I would check the Charging System.
Is it a Generator or some kind of Alternator conversion? Could be a Serious Overcharge!

[Jeffry Cassel]

The headlights ought to be on a circuit breaker-they are not fused. One would think a short to ground would blow the breaker or fuse regardless of whether the engine were running or not. Have halogen lamps been installed? They draw power. If you aren't pulling more than 30amps, isolate and check every branch of the light system 'til you find the culprit. If you have a fuse, someone not too knowledgeable has been messing with the wiring ; there is nothing more frustrating to try to unravel. Don't forget to carefully check every light socket and both headlight buckets and grounds---they corrode and offer a lot of resistance. Best of luck.

[Lark Hunter]

Headlights and dash lights work when i put in the new 30 amp fuse
when I turn on engine (this is a 289 car with blower) seems like fuse pops

The headlamp circuit should not be on a 30 amp fuse. I think a 20 amp breaker is what was specified. I will guess that someone "uprated" the circuit indiscriminately at some point in time... like stepping up to a higher amperage fuse each time until it doesn't blow anymore... or the wiring finally blows to protect the fuse.

I don't have 1955 wiring diagrams at the ready, but you can get yourself pointed in the general direction by eliminating different parts of the lighting circuit. First, replace that fuse with a 20 amp (we can figure out why you've got a fuse in place of a circuit breaker later. In the mean time, perform your tests when headlights suddenly going out won't leave you in blackness). Turn dash lights off, and just parking lights on... see if you can replicate the fault this way. Next, add the dash lights back to the mix... Then, turn on the headlights on whichever beam was not in use when fuse was blowing... So, if you had them on low beam, try try high beam. This will at least narrow it down a little bit.

[Lark Hunter]

Have halogen lamps been installed? They draw power.

almost exactly the same as the standard tungsten source they replaced . Even if someone unscrupulously used a lamp with a 100/130 watt H4, x2= 260 watts. A 30 amp fuse will provide you with 360 watts (I'm assuming the car has 12 volt electrics with the 289 swap).

[keithwahl]

HELLO EVERYBODY AND THANKS FOR THE INFO. This car was built by Bob Halgren and he knows what he is doing
The car was completely rewired. We did wire led turn signals into the back up lamps which are on a separate circuit.
I have Fender spears with LED turn signals. Original style Headlights were used. I do not know about a circuit breaker.
I went and turned the car on and ran scenarios with the lights and everything is working.. but we will go through the system. The car has air conditioning and an alternator.. Appreciate any other information...
Keith

[doofus]

Check out the oft overlooked dimmer switch.Luck Doofus

[keithwahl]

Bob Halgren Built this car. He knows what he is doing. He chose a fuse and not a circuit breaker.
I may have an issue with my left parking light up front. Will be checking
Does anyone use an audible circuit tester for shorts>?
Keith

[keithwahl]

good thought doofus!