Fuse blowing: On the radio/lighter/dome light circuit

Gbauer · Dec 30, 2013

I'm having trouble tracking down an issue with a fuse blowing and looking for advice on where it might be.

I've isolated the problem somewhat by clipping the wire for the dome and glove box light. Now the radio and lighter both work and the fuse is holding. So the bare/broken/pinched wire is somewhere in the dome/glove box wiring.

I physically traced the glove box light wire back and it looks like it's OK. So I'm thinking it's on the dome light or door switches.

I recently took apart the interior to patch some holes in the floor and add sound deadening. Because of that I think the pinch is somewhere in floor area.

My question is where does the dome light wire physically run? Along the driver's side door, up through the rear quarter and through the sail panel on the driver's side? If so I know where to start tomorrow: Pull the carpet along the driver's side door and remove the flashing (or whatever that piece is called) and check there. Does that sound like a good place to start?

...or am I way off on where this wire runs?

click · Dec 30, 2013

George, the door switches actually are switching the 'ground' side of that circuit. It is common to find rust has gotten into those switches. They are easy to work on, remove the nut that holds them in the door frame and pull out slowly. Inspect both of them and I bet you find a loose wire or bad switch...if the contacts have come together, that becomes a dead short right there.

Gbauer · Dec 30, 2013

Thanks! I'll look there first. Didn't consider that area...

BPOS · Dec 30, 2013

click said:
George, the door switches actually are switching the 'ground' side of that circuit. It is common to find rust has gotten into those switches. They are easy to work on, remove the nut that holds them in the door frame and pull out slowly. Inspect both of them and I bet you find a loose wire or bad switch...if the contacts have come together, that becomes a dead short right there.

Can't really get a short circuit on the ground side. Worst scenario in Jim's deal is that the dome light would always be on or the key buzzer wouldn't shut off. A problem in a door jamb switch shouldn't cause a fuse to blow.

You need to look for a place where the hot side of the circuit is going to ground. The wire is orange, and goes to the clock, the lighter and the courtesy/dome lights from the fuse panel. A fairly common place for a short is in the wiring to the rear console courtesy light (if you have a console) That bulb gets hotter than the hubs of hell and can melt the wiring at the socket, or the hot and the ground can get pinched together between the top and bottom shells of the console. I suppose a defective lighter socket could cause a short as well. Or a bad bulb socket, or clock etc. You'll just have to dig around to find it.

click · Dec 30, 2013

Al is right,, my remedy was only to find if there was a switch issue at all, it would leave lights on and not blow... my error in thinking too quickly. Definately some hot wire is pinched or touching ground somehow.

daverichard · Dec 30, 2013

Have you messed with the console? I had the same problem and I found the wire running to the back of the console light (orange wire) was caught under the bolt that attaches the rear of the console to the floor. The location of the wire makes this very easy to occur.

Gbauer · Dec 30, 2013

I don't have a center console. Just a dealer-installed clock on the hump. I can try that part of the circuit and see if it's pinched there since I had to remove and reinstall it for the floor work.

blue89bird · Dec 31, 2013

I have a similar issue I'm trying to figure out. If I leave any of the doors open for more than a few minutes, the 15a fuse pops that powers the dome lamp, dash lights and radio.

Dome lamp harness is new, no wires I can tell are pinched, etc. I've learned to not leave the door open and keep a bunch of fuses in the console.

Gbauer · Dec 31, 2013

That's pretty similar to mine. It's intermittent.

I'll dig into it today and see what I can find.

rogerh · Jan 1, 2014

The dome light wires and connector should be visible from the trunk. Right under the package tray on the left side. I would start by removing the dome bulb and checking the socket. If its not there check the wires in the trunk and disconnect the connector. That would take the wire going to the dome socket out of the circuit. The rear harness runs along the inside the left side rocker. The rear harness should be protected pretty well until it goes into the trunk.

Roger

Gbauer · Jan 2, 2014

So I dug in today...

tested the dome light circuit at the trunk plug: no grounding there.

Tested the orange wire at the plug right by the fuse block: not open at side facing dome, open at other end. Tested at point where radio and lighter brach off: they're both Ok. Still grounded on other end.

The only part I think that's left is the headlight switch. Tested plug: wire side no grounding. So I think the switch is bad.

Does anyone know how to test a non-rs headlight switch? Also does the power for this circuit run through the headlight switch, into the radio/lighter? Where do the other components come into play? Glove box light and door switches?

BPOS · Jan 2, 2014

The door jamb switches and the dome light part of the h/l switch all switch the ground side of the circuit. The orange wire should be hot at all times if the fuse is good.

Check your e-mail - I sent you a couple wiring diagrams - don't know how to post PDF's here.

Gbauer · Jan 2, 2014

Got the diagrams! Big thanks!

so I think I'm on the right track with the headlight switch. All circuits were open to ground until I got to the switch. It's original so it's a good bet it's the culprit. Also a $12 part so cheap enough to try....

yellow69RS · Jan 2, 2014

The H/l switch is the ground side of the dome light circuit. It can't blow a fuse, if you ground it there the light comes on. You keep mentioning the radio.... on the original set up the radio is not on this circuit. I understand newer aftermarket radios have a battery connection to keep the clock and memory alive. I think your problem might be with the radio.

Jeff

Gbauer · Jan 3, 2014

yellow69RS said:
The H/l switch is the ground side of the dome light circuit. It can't blow a fuse, if you ground it there the light comes on. You keep mentioning the radio.... on the original set up the radio is not on this circuit. I understand newer aftermarket radios have a battery connection to keep the clock and memory alive. I think your problem might be with the radio.

Jeff

doesn't blow when the radio is in the circuit. only when the dome light is in it.

the orange wire physically goes to the h/l switch. i traced it there. that said i didn't pull apart the clock. i'll need to test that again tomorrow...

Robs67rs · Jan 3, 2014

Have you guys ever thought of a bulb causing the short ? Not the socket but the bulb it self. I see this happen all the time

Gbauer · Jan 3, 2014

Never heard of that happening.

I'll try the headlight switch first since Autozone has one in stock by my house (and by the pictures it's the correct one). If that doesn't do it I'll get a new bulb. I traced the wires the best I could and all seem to be OK: no frays or breaks.

Hopefully I'll know tonight and will update the thread. I'll try to run some continuity tests on both switches as well to see if I can help others in the future test their switch before replacing (if someone does a search and finds this thread).

rogerh · Jan 3, 2014

Robs67rs said:
Have you guys ever thought of a bulb causing the short ? Not the socket but the bulb it self. I see this happen all the time

You are right but I believe you are talking about the 67 sail panel lights. Those bulbs are double contact bulbs and if you install a single contact bulb in the double contact socket it shorts to ground. I believe George's dome light bulb is tubular and has the contacts on the ends of the bulb.

Roger

Robs67rs · Jan 3, 2014

Gbauer said:
Never heard of that happening.

I'll try the headlight switch first since Autozone has one in stock by my house (and by the pictures it's the correct one). If that doesn't do it I'll get a new bulb. I traced the wires the best I could and all seem to be OK: no frays or breaks.

Hopefully I'll know tonight and will update the thread. I'll try to run some continuity tests on both switches as well to see if I can help others in the future test their switch before replacing (if someone does a search and finds this thread).

Don't need to replace bulbs at the moment, If I have followed correctly you have it down to 2 circuits dome light and glove box correct ? What I would do is first remove your dome light bulb and check to see if short circuit is still present , if so do the same to your glove box bulb. its a one minute test and it can save you hours of headaches .

Robs67rs · Jan 3, 2014

rogerh said:
You are right but I believe you are talking about the 67 sail panel lights. Those bulbs are double contact bulbs and if you install a single contact bulb in the double contact socket it shorts to ground. I believe George's dome light bulb is tubular and has the contacts on the ends of the bulb.

Roger

Sorry for not being more specific and yes have found several shorts caused by
people installing the wrong bulb Lol ,,, I have also found where the actual light bulb filaments thins, weekends or a very small part of the filament that has broken off causing high resistances to a point where it causes a short circuit, And yes bulb would still work .

Fuse blowing: On the radio/lighter/dome light circuit

Gbauer

click

Gbauer

BPOS

click

daverichard

Gbauer

blue89bird

Gbauer

rogerh

Gbauer

BPOS

Gbauer

yellow69RS

Gbauer

Robs67rs

Gbauer

rogerh

Robs67rs

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