Technical Frustrated........

[Hooli 76]

Hi folks, new to this but here goes........have a 1979 124 Spider which keeps blowing a fuse when I turn the lights on. Have searched, chased, cleaned & replaced everything I can get my hands on but to no avail! Everything works fine when no lights needed, brake lights etc but hit that light switch & we have our very own mini firework display!

Incidentally, have recently replaced all the headlamp bowls, gaskets & adjuster screws on both sides for less than £30 if anyone's interested, they are the same as a certain old british classic, let me know if you need any info (my trump card to get the info I require!)

 

[GeorgeT]

Did you replace the headlights themselves with brighter lamps?

The best solution to this is to install a pair of relays for the headlights (one for low beams and one for high). The relays will take the high current load off the fuse, light switch, the high beam lever and the ignition switch. You will then have a low current going through these components to the relays. The relays should be powered off a 10 or 12 gauge, fused wire from the alternator or the starter relay.

 

[MN Spiderman]

hopefully you got this fixed by now.. But i will put in my two cents. the ground wires on a fiat are not soder'd to the anchoring clips. They are just crimped. They get corroded, even if they don't look like it. Water is attracted to bare wires. So the problem is (maybe) that your headlights don't have a good ground anymore. Why is this so important? because if you put 12 volts to your headlights, your headlights have to be able to discharge 12 volts at the same speed it accepts it. Same as anything on your car. slow blinkers, dim tail lights, dim headlights, etc. they all work but poorly, all because of a bad ground. Electric needs an even flow, 12 in 12 out, 4 in 4 out, etc. people run 0 gage for their big ass amps, and then only use 4 gage for ground. not proper. So when your headlights can't discarge the full 12 volts, the voltage backs up and overheats your fuse and blows it. just like that.