High Beams Blowing Fuses

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RPMagoo

Just An Old Motorhead
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When I switch to high beam, on the head lights, I blow a 20 amp fuse. It appears, on My amp gage, that I have a problem with the charging system (alternator / VR), the amp gage stays at Xero ( no charge), or below. I do not blow fuses on low beam. -- My current alternator is , only, putting out 30 amps, And I have a electric fan. Is it possible that if I replace the alternator, and / or the regulator, that My problem will go away ? -- I have checked, all, grounds.
 
When I switch to high beam, on the head lights, I blow a 20 amp fuse. It appears, on My amp gage, that I have a problem with the charging system (alternator / VR), the amp gage stays at Xero ( no charge), or below. I do not blow fuses on low beam. -- My current alternator is , only, putting out 30 amps, And I have a electric fan. Is it possible that if I replace the alternator, and / or the regulator, that My problem will go away ? -- I have checked, all, grounds.

You have two separate problems there.
Sounds like a dead short to ground on the high beam circuit in either the main switch, the hi low switch or wires themselves.

Then you can deal with the no charging issue, and a volt meter and/or a test light will be your best buddies in no time.
Heck you might find the reason for both at the same time.:D
 
There's a dead short to ground somewhere in the high beam circuit. I have started at the headlight switch and diagnosed forward to eventually find a wire lug snapped off the back of a sealed beam, touching the ground lug. If I had been told this car had recent collision repair... Good hunting.
 
When I switch to high beam, on the head lights, I blow a 20 amp fuse. It appears, on My amp gage, that I have a problem with the charging system (alternator / VR), the amp gage stays at Xero ( no charge), or below. I do not blow fuses on low beam. -- My current alternator is , only, putting out 30 amps, And I have a electric fan. Is it possible that if I replace the alternator, and / or the regulator, that My problem will go away ? -- I have checked, all, grounds.

Let's START with this 20A fuse. Mopars DO NOT HAVE a fuse in the headlights circuit

So what IS this fuse you are blowing? Is this something you or someone else added?

See if the fuse holder gets HOT. bad connections in the fuse holder / clips will head a fuse and cause it to blow
 
- Let's START with this 20A fuse. Mopars DO NOT HAVE a fuse in the headlights circuit --
-- This is a 33 Ford Hot rod - Totally re-wired. -- I installed a new alternator, and VR, and the charging problem is gone.
 
Let's START with this 20A fuse. Mopars DO NOT HAVE a fuse in the headlights circuit

So what IS this fuse you are blowing? Is this something you or someone else added?

See if the fuse holder gets HOT. bad connections in the fuse holder / clips will head a fuse and cause it to blow

Hey that's right, there is no fuse for the headlights.
Something isn't wired right, or the headlights circuit is sending power directly to ground through that fuse.
So the high beams go off when the fuse blows, right?
I know that sounds like a dumb question, but it may not be, as it could blow that fuse then the lights stay on and it might tell us something important.
 
-- This is a 33 Ford Hot rod - Totally re-wired. -- I installed a new alternator, and VR, and the charging problem is gone.

OK............As I said look for heat at the fuse holder, and then measure your running/ charging voltage with headlights, etc on and engine simulating low/ medium cruise RPM

If those two seem OK, look for something like a bare wire short. Have you changed headlights, that is, DID THEY EVER work or did this just crop up? In other words what is the wattage rating on the lamps?
 
Change out the headlights. Might have a short right in the bulb. Element burns out, drops across to the other side, dead short.
 
^^That could be, but you should be able to run that down easy. Run with first one, then the other headlight unplugged. Surely BOTH are not shorted LOL. Of course if intermittent it could take some time.
 
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