Dome Light Fuse Blowing????

mopower76

Well-Known Member
Joined
Feb 3, 2013
Messages
78
Reaction score
48
Hey All!
I’m having issues with my 1987 Chrysler Fifth Avenue blowing the fuse for the dome light/courtesy lights/trunk light etc.
I’ve tried replacing all bulbs and checking all of the connections and grounds I could trace back while I had the majority of the interior out to no avail.
The only strange thing is the ignition switch, I replaced it as I had no original keys with the car so I removed the tumbler and had keys made from it and the trunk tumbler. When the key is turned back to accessory sometimes it has power sometimes no power… (Radio won’t come on)
Everything else works as it should.
Ideas? Is the ignition switch related to the dome light circuit?
Any help would be appreciated!
Thanks!!!

IMG_9736.jpeg


IMG_9869.jpeg
 

mopower76

Well-Known Member
Joined
Feb 3, 2013
Messages
78
Reaction score
48
BTW… I do not recall if the dome light worked when I first put power to the car. It had been sitting since 2004.
 

mopower76

Well-Known Member
Joined
Feb 3, 2013
Messages
78
Reaction score
48
I just swapped the known good alternator and voltage regulator from my old reliable daily 79 LeBaron and same issue, it’s actually showing 18V before I shut it off.
I have extra grounds to the alt case and to the volt reg.
I was sure hoping that the alternator or VR would have been the culprit.
 

mopower76

Well-Known Member
Joined
Feb 3, 2013
Messages
78
Reaction score
48
I’m thinking there has to be a connection between the dome lights blowing fuses and overcharging…
I’m for fear that the ignition switch within the steering column wiring could be the issue.
I know these GM tilt columns are horrible to change the ignition wiring.
 

mopower76

Well-Known Member
Joined
Feb 3, 2013
Messages
78
Reaction score
48
OK… Lesson learned, try a different voltmeter!
Change batteries in my old fluke voltmeter got a completely different reading then use the neighbors, cheap craftsman voltmeter and it showed 14.98 when running.
 

AMC Diplomat

Well-Known Member
Joined
Feb 14, 2023
Messages
951
Reaction score
450
Location
NY
OK… Lesson learned, try a different voltmeter!
Change batteries in my old fluke voltmeter got a completely different reading then use the neighbors, cheap craftsman voltmeter and it showed 14.98 when running.
14.98 is still too high
 

Aspen500

Well-Known Member
Joined
Feb 14, 2015
Messages
7,002
Reaction score
2,739
Location
Rib Mountain, WI
The dome, trunk, etc lights are constant power and the ground is switched by the door jamb switches, headlamp switch, and so on.

A short to ground in the positive ckt, or socket for any of the lights will blow the fuse. I've seen trunk light wiring short inside the deck lid before. Not on an F or M body specifically, but on various cars at work over 40 years. It'd be worth a check anyway. I'm just assuming the trunk light is in the lid on an '87 5th. If not,,,,,,never mind :)
 

AMC Diplomat

Well-Known Member
Joined
Feb 14, 2023
Messages
951
Reaction score
450
Location
NY
On my 87 diplomat, the fuse for the courtesy lights was the same as the taillights. So if you messed with your taillights recently and now the fuse is blowing, I'd look there first.
 

AMC Diplomat

Well-Known Member
Joined
Feb 14, 2023
Messages
951
Reaction score
450
Location
NY
20240128_185535.jpg20240128_185549.jpg
20240128_185108.jpg20240128_185147.jpg20240128_185205.jpg
I don't know how well these pictures will turn out, but these are the fuses for the car, the connections in the column, and the wiring diagram for the dome light. This is all 87 specific. 88 is different. Idk about 86, probably different too because mopar changed little things year to year.

My tailights were a mess. And the vanity mirror on the passenger side was shorting out inside the A pillar.
 

GregG48213

Well-Known Member
Joined
Sep 28, 2017
Messages
99
Reaction score
46
Location
Detroit MI
Is the ignition switch related to the dome light circuit?
I would look into the possibility that when working on the ignition switch, the wire for the ignition switch lamp got pinched or grounded. It looks like you might be able to deactivate the lamp by yanking the time delay relay.
 

mopower76

Well-Known Member
Joined
Feb 3, 2013
Messages
78
Reaction score
48
I would look into the possibility that when working on the ignition switch, the wire for the ignition switch lamp got pinched or grounded. It looks like you might be able to deactivate the lamp by yanking the time delay relay.
I’ll give that a try!
Thanks!
 

mopower76

Well-Known Member
Joined
Feb 3, 2013
Messages
78
Reaction score
48
So I am finally getting ready to drive the FiFth and just realized along with the interior lights not working my wife told me the brake lights are not working either… Are they related??

I’m pulling the steering column back out to check wiring… Better than being upside down.

I just today sold my 79 LeBaron driver and was hoping to drive the FiFth Ave to work tomorrow…. Not happening without brake lights…
 

mopower76

Well-Known Member
Joined
Feb 3, 2013
Messages
78
Reaction score
48
View attachment 51938View attachment 51937
View attachment 51941View attachment 51940View attachment 51939
I don't know how well these pictures will turn out, but these are the fuses for the car, the connections in the column, and the wiring diagram for the dome light. This is all 87 specific. 88 is different. Idk about 86, probably different too because mopar changed little things year to year.

My tailights were a mess. And the vanity mirror on the passenger side was shorting out inside the A pillar.
Hey!!!! I can’t believe I missed this post!!!
Thanks SO MUCH!!!
 

AMC Diplomat

Well-Known Member
Joined
Feb 14, 2023
Messages
951
Reaction score
450
Location
NY
So I am finally getting ready to drive the FiFth and just realized along with the interior lights not working my wife told me the brake lights are not working either… Are they related??

I’m pulling the steering column back out to check wiring… Better than being upside down.

I just today sold my 79 LeBaron driver and was hoping to drive the FiFth Ave to work tomorrow…. Not happening without brake lights…
See post #9

They're on the same fuse
 

Mikes5thAve

Well-Known Member
Joined
Mar 3, 2020
Messages
1,336
Reaction score
519
Location
Canada
Funny that they put something important like brake lights on a fuse that's a higher chance of blowing with everything on it.
Then again if you know that the brake lights and interior lights are on the same fuse it's a good indication that if your interior lights don't work you probably don't have brake lights too.
 

AMC Diplomat

Well-Known Member
Joined
Feb 14, 2023
Messages
951
Reaction score
450
Location
NY
Funny that they put something important like brake lights on a fuse that's a higher chance of blowing with everything on it.
Then again if you know that the brake lights and interior lights are on the same fuse it's a good indication that if your interior lights don't work you probably don't have brake lights too.
On my car, a "genius" previous owner put a 30 amp fuse in to "solve" the problem instead of checking the wiring
 

Aspen500

Well-Known Member
Joined
Feb 14, 2015
Messages
7,002
Reaction score
2,739
Location
Rib Mountain, WI
Funny that they put something important like brake lights on a fuse that's a higher chance of blowing with everything on it.
Then again if you know that the brake lights and interior lights are on the same fuse it's a good indication that if your interior lights don't work you probably don't have brake lights too.
You hit it right on the head. It actually is why they did it that way. You'll notice right away if the interior lights are out. If the brake lights are out, you would know it until the next time you checked the lights, someone told you or,,,,,the vehicle behind runs into you.
 
Back
Top