Fuses getting hot

[mxl556]

Hi All,

I have been working on the electrical system, replaced ground straps and cleaned the connections. When I was testing things I noticed that the headlight fuses are getting hot when headlights are on, hot enough to burn yourself. Fuel pump fuse is little warm, but both headlight fuses got very hot just after a few minutes. Any ideas why?

Fuses are old but they are not loose and there is no obvious corrosion/oxidation anywhere. Nothing seems to be out of ordinary and all the connections seemed OK inside the fuse panel. I am planning to replace the fuses with new and double check the connections underneath. Is it possible that 55W Hella lights (vs 35W sealed beams) cause this? I would think if the load is too much, it would blow the fuse, but maybe I am missing something.

Thank you.

[jakub421]

I would say it's normal. I've definitely felt the fuel pump fuse get hot, assuming it would be the same on the headlights as well.
You can increase the value of the fuse, with 2x 55w vs 2x 35w you're pulling over 4 more amps.

[320iAman]

The fuel pump relay is overtaxed in these cars and this is why it gets hot, runs both fuel pumps, warm up regulator, air auxillary valve, and the main relay, I did the Hella upgrade some time ago, now the fuel pump relay runs both fuel pumps and the main relay( supplied with 100-300 milliamps) and stays a lot cooler and has longer life to boot. Yes pulling more amps thru 8 amp fuses than stock causes them to get hotter.

Randy

[DavidF]

Hi All,

I have been working on the electrical system, replaced ground straps and cleaned the connections. When I was testing things I noticed that the headlight fuses are getting hot when headlights are on, hot enough to burn yourself. Fuel pump fuse is little warm, but both headlight fuses got very hot just after a few minutes. Any ideas why?

Fuses are old but they are not loose and there is no obvious corrosion/oxidation anywhere. Nothing seems to be out of ordinary and all the connections seemed OK inside the fuse panel. I am planning to replace the fuses with new and double check the connections underneath. Is it possible that 55W Hella lights (vs 35W sealed beams) cause this? I would think if the load is too much, it would blow the fuse, but maybe I am missing something.

Thank you.

I would say you need to check all electrical connections in the headlight circuit...clean them all and ensure they are tight. Dirty or loose connections cause amperage to increase. Grounds and 12v supply need to be clean and tight. Fuses that burn you can or will eventually damage the fuse block (i.e. melt plastic).

[mxl556]

Getting rid of H4 lights helped a lot. Replacement of fuses and lightly sanding the fuse holders solved the problem.