Why are all my fuses popping?!

[1979-square-body]

My head light fuse keeps popping fuse after fuse.

I've gone through a few just to make sure it wasn't the fuse itself. Was fine a few days ago. Using 30 amps...

Any ideas??

[1979-square-body]

Should I up my amperage? Use a paper clip??

[dfrank]

This may sound stupid but check inside your cigarette lighter if you have one. I had a penny get stuck in the bottom of the cigarette lighter in my truck while offroading once and it kept blowing fuse after fuse as soon as i put them in. Drove me nuts trying to figure out why it was doing that. Lol

[1979-square-body]

Hmmm I'll have to check. I just opened and closed that the other day, maybe messed something up

[wilkin250r]

The best way to chase electrical gremlins is by process of elimination, and it's MUCH easier if you have and can understand a wiring diagram.

Basically, you look at the wiring diagram and find ALL the components in the system. For example, let's say the radio, dome light, and cigarette lighter are all on the same fuse, and it keeps blowing.

First, you disconnect the radio, and turn the circuit on, and the fuse still blows. Reconnect the radio, and then you disconnect the dome and interior lights, and the fuse still blows.

Reconnect the lights, and disconnect the cigarette lighter, and fuse doesn't blow. Eureka, the problem is in the cigarette lighter.

[greg64]

One other tip... Instead of feeding fuse after fuse into the circuit until you find the problem, connect the high beam filliment of a head light bulb across where the fuse normally would be. If the circuit is operating normally, the bulb will be out or glow dimly. When a dead short occurs that would blow the fuse, the bulb will glow brightly.

[1979-square-body]

I understand the wiring diagrams and can chase them down which will come in handy here soon. I was just making sure this wasn't the result of a common occurrence IE the cigarette lighter thing.

Next issues is, when I bought the truck (as a running project) the head lights, high beams, blinkers and tail lights worked. And that was it. Literally. The truck was wired just enough to make it road legal. All the interior, dash and license plate light are non existent due to the Painless wiring system only being hooked up under the hood and the exterior lights. So at this point, I have no idea if any of the gauges work or any of the interior lights, ac/heat or even if the radio wires are working. I have a radio hole with all the ends of the wires hanging through and zip tied. Good thing is I have a lot of experience wiring up custom motorcycles and building wiring harnesses. I just don't really like to chase them down.

Next step is order a switch because the one I have is what I believe the culprit to be. They worked last week, tried to use them last night after I pulled the gauges out of the dash to have a look see. I'm gonna need a whole new cluster, just done know if I am going to use the existing gauge shroud or make one.

[Gregski]

Originally Posted by wilkin250r

The best way to chase electrical gremlins is by process of elimination, and it's MUCH easier if you have and can understand a wiring diagram.

I stopped reading here, LOL

[Gregski]

Originally Posted by 1979-square-body

All the interior, dash and license plate light are non existent due to the Painless wiring system only being hooked up under the hood and the exterior lights.

there it is, someone messed with the wiring harness / replaced it, plot thickens as this is no longer stock, funny thing about them Painless wiring kits, my buddy just picked one up for his '73 Challenger and it don't look Painless at all, it came with what looks like a kitchen freezer bag full of the cheap yellow and blue connectors you get in a variety kit at AutoZone, just sayin'

[franken]

First, fuses burn because too much current is flowing through them and they melt. This is what they are designed to do so the wires don't melt and cause a fire.
Next, you need to find what causes too much current.
All current goes from the battery/alt + to the battery/alt -. Its a circle. The same out, the same in.
The headlights draw a certain amount of current. If the circuit burns fuses, you have a short.

[Liberty]

I thought headlights weren't fused?

[1979-square-body]

On my 79 she has a spot with a 30 amp.

[1979-square-body]

Well looks like I'm gonna have to use what I have and make the painless work. I really do t want to have to buy another harness. I can get a stock schematic and go through that and the painless system and make it work.

[wilkin250r]

Originally Posted by 1979-square-body

when I bought the truck (as a running project) the head lights, high beams, blinkers and tail lights worked. And that was it. Literally. The truck was wired just enough to make it road legal. All the interior, dash and license plate light are non existent

I feel your pain, it sounds EXACTLY like my 79, even down to the gauges. When I got it, it ran, the headlights and tail lights worked, and that was it. I think the only gauge that was functional was the speedometer, and probably only because it was a mechanical connection and not electrical.

I swapped out the entire cluster with a decent unit from the local junkyard, and I'm now in the process of a complete HVAC overhaul.