Full Version: Headlight Wiring
Just installed fuses that have been missing on my low beams and noticed the tabs under the fuses get hot when my headlights are on. I'm guessing this was the case since I bought the car because I seldom use the headlights. I pulled all four fuses and reinstalled them one at a time. Every one gets hot. This leads me to believe it's a grounding problem but everything visible looks good. Any common problem areas to look at first?
see what headlights you have installed, maybe h-4 with 100 watt beams? That would make the fuses hot
Just installed fuses that have been missing on my low beams and noticed the tabs under the fuses get hot when my headlights are on. I'm guessing this was the case since I bought the car because I seldom use the headlights. I pulled all four fuses and reinstalled them one at a time. Every one gets hot. This leads me to believe it's a grounding problem but everything visible looks good. Any common problem areas to look at first?
QUOTE(twistedstang @ Aug 6 2019, 01:00 PM) 
Just installed fuses that have been missing on my low beams and noticed the tabs under the fuses get hot when my headlights are on. I'm guessing this was the case since I bought the car because I seldom use the headlights. I pulled all four fuses and reinstalled them one at a time. Every one gets hot. This leads me to believe it's a grounding problem but everything visible looks good. Any common problem areas to look at first?
Are the fuses getting hot or just the tabs holding them in? Do the headlights work? If they do work then chances are you don't have a short. A short would blow the fuse.
It's likely not a grounding problem but an oxidation problem on the fuses and the tabs. Heat comes from power dissipation and power dissipation is PD = I x I x R where R is resistance. If you have no resistance, you have no power dissipation and no heat. Clean the fuse ends and the tabs. I just did this with my dremel tool with a wire wheel. The fuse ends and the tabs should be nice and shiny.
It's likely not a grounding problem but an oxidation problem on the fuses and the tabs. Heat comes from power dissipation and power dissipation is PD = I x I x R where R is resistance. If you have no resistance, you have no power dissipation and no heat. Clean the fuse ends and the tabs. I just did this with my dremel tool with a wire wheel. The fuse ends and the tabs should be nice and shiny.
QUOTE(Spoke @ Aug 6 2019, 04:30 PM)
Are the fuses getting hot or just the tabs holding them in? Do the headlights work? If they do work then chances are you don't have a short. A short would blow the fuse.
It's likely not a grounding problem but an oxidation problem on the fuses and the tabs. Heat comes from power dissipation and power dissipation is PD = I x I x R where R is resistance. If you have no resistance, you have no power dissipation and no heat. Clean the fuse ends and the tabs. I just did this with my dremel tool with a wire wheel. The fuse ends and the tabs should be nice and shiny.
I steal an emery board out of Betty's nightstand and sand down the tabs.
Thanks guys. Those will be the first two things I check today.
I gave everything a once over yesterday. I cleaned up the connectors on the fuse panel and also made sure the connectors at the headlights looked good. I discovered the taillight fuses were also getting hot as well as the ground tabs near the headlight boxes. Checking out the taillights, I found a few connectors that were pulled off maybe 2/3 of the way. I'm guessing from years of stuff bouncing around in the trunk.
Concerning the headlight wattage, I didnt find anything on them stating the wattage nor could I find anything online when I googled it. Is it traceable to the part number stamped on the lens?
Anyhow, looks like it was some overdue maintenance that may have prevented a fire.
Thanks again for the help everyone.
Concerning the headlight wattage, I didnt find anything on them stating the wattage nor could I find anything online when I googled it. Is it traceable to the part number stamped on the lens?
Anyhow, looks like it was some overdue maintenance that may have prevented a fire.
Thanks again for the help everyone.
QUOTE(twistedstang @ Aug 8 2019, 07:05 AM)
Concerning the headlight wattage, I didnt find anything on them stating the wattage nor could I find anything online when I googled it. Is it traceable to the part number stamped on the lens?
Often times is it on the back of the headlight, you may need to pull them to know for sure.
Glad you caught it before something undesirable happened.
Measure your headlamp amp draw to solve. A x V=W 
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