Fox Dome light not working

Ryu

Member
Jun 22, 2015
37
1
8
Hey guys I'm having a issue with my dome light in my 93 mustang LX and a battery draining issue and I assume they are related because my battery was dead as I noticed my dome light was not turning on. I checked the #8 fuse which is as far as I know is the corresponding fuse which was fine and I popped the dome light cover off and the bulb itself is not blown, and after some quick research the only other thing I've found was LMR's door jam switch replacement. I was hoping yall could give me some more direction before I assume my door jam switches are the problem and get some new ones.
 
  • Sponsors (?)


Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
39,720
15,495
224
Massachusetts
Do you have 12V to ground up at the dome light when the light should be on?

The domelight grounds itself to the vehicle's roof, so it could be an issue of corrosion on the electrical contacts. If the fuse is fine, next step is to verify if you do have 12V at the light.

If you don't, then i'll see if i can get a pic of the courtesy light diagram for a 93 later today when i get home. The wiring runs around a bit due to going to both door switches and the hatch

Is this a hatch or a coupe?
 

Ryu

Member
Jun 22, 2015
37
1
8
Do you have 12V to ground up at the dome light when the light should be on?

The domelight grounds itself to the vehicle's roof, so it could be an issue of corrosion on the electrical contacts. If the fuse is fine, next step is to verify if you do have 12V at the light.

If you don't, then i'll see if i can get a pic of the courtesy light diagram for a 93 later today when i get home. The wiring runs around a bit due to going to both door switches and the hatch

Is this a hatch or a coupe?
Not to sure about the 12v ground, but I didn’t take apart the dome light more to see it’s internals. but It’s a hatchback
 

Mindseye007

Active Member
Oct 21, 2020
167
21
28
ontario
Hey guys I'm having a issue with my dome light in my 93 mustang LX and a battery draining issue and I assume they are related because my battery was dead as I noticed my dome light was not turning on. I checked the #8 fuse which is as far as I know is the corresponding fuse which was fine and I popped the dome light cover off and the bulb itself is not blown, and after some quick research the only other thing I've found was LMR's door jam switch replacement. I was hoping yall could give me some more direction before I assume my door jam switches are the problem and get some new ones.
You might need a new dimmer switch I had the same problem with the dome light and this fixed it for me.

 

Ryu

Member
Jun 22, 2015
37
1
8
(Can’t figure out how to edit messages so….anyway) the glove box light works just fine and also come on just so everyone knows. As well as my rear view side mirrors.
 

Ryu

Member
Jun 22, 2015
37
1
8
Mustang5L5 said

Do you have 12V to ground up at the dome light when the light should be on?

The domelight grounds itself to the vehicle's roof, so it could be an issue of corrosion on the electrical contacts. If the fuse is fine, next step is to verify if you do have 12V at the light.

If you don't, then i'll see if i can get a pic of the courtesy light diagram for a 93 later today when i get home. The wiring runs around a bit due to going to both door switches and the hatch

Is this a hatch or a coupe?

———————————————

It all looks okay to me
 

Attachments

  • image.jpg
    image.jpg
    801.8 KB · Views: 24

Mindseye007

Active Member
Oct 21, 2020
167
21
28
ontario
You think I would still need a new dimmer switch if its just the center dome light that is not working and when I adjust the dimmer switch the instrument panel dims properly?
Was the dimmer switch ever changed before? It should make a click sound when you turn it all the way counterclockwise that turns the dome light on. Mine did the same thing with the dimming of the dash lights too so after I changed the switch the lights dimmed and the dome light worked again. Did you try installing a new bulb?
 

Ryu

Member
Jun 22, 2015
37
1
8
Was the dimmer switch ever changed before? It should make a click sound when you turn it all the way counterclockwise that turns the dome light on. Mine did the same thing with the dimming of the dash lights too so after I changed the switch the lights dimmed and the dome light worked again. Did you try installing a new bulb?
As far as I know the dimmer switch was never replaced and the dimmer does make a click when I turn the brightness all the way up, and I tried a different bulb that I know is working but still didn't work, but to be on the safe side I'm going to order a couple different bulbs, I would be a little embarrassed if it was as simple as a burnt out bulb but I would also be relieved that its a simple and easy fix, the reason I don't think its just a burnt out bulb is the dead battery issue I seemed to have at the same exact time as the bulb not working, would a burnt out bulb cause a parasitic draw enough to drain a battery in 12 hrs?

Previously I have been driving around with the #8 fuse removed from the fuse box (which eliminated my cars battery dying) and I am going to reinstall the #8 fuse in the fuse box which gives me back my radio which I did install myself....over 4 years ago and never had a problem with it ever before, so I really Highly doubt thats the issue.

And i'm going to take off the dome light housing as a whole to see if my battery dies any time soon, while I wait for the bulbs I ordered to arrive.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
39,720
15,495
224
Massachusetts
Cargo light and dome light are wired together. If you flip the dimmer to dome light on (cargo light come on too) it bypasses all the door switches on wire 53 and the dome light should come on.


If it doesn’t, and the cargo light is on. Check for actual 12v positive to ground on the black/light blue wire. You should have it. If you don’t but the cargo light is on, there’s a break in the wire after the dimmer.

If you do, there is an issue with the dome light itself.

If the cargo light is dining and coming on as it should, the issue is not in the dimmer its after it. Flip the dimmer to the side that turns the cargo light on and check for voltage.
 

Mindseye007

Active Member
Oct 21, 2020
167
21
28
ontario
Hey guys I'm having a issue with my dome light in my 93 mustang LX and a battery draining issue and I assume they are related because my battery was dead as I noticed my dome light was not turning on. I checked the #8 fuse which is as far as I know is the corresponding fuse which was fine and I popped the dome light cover off and the bulb itself is not blown, and after some quick research the only other thing I've found was LMR's door jam switch replacement. I was hoping yall could give me some more direction before I assume my door jam switches are the problem and get some new ones.
did you fix your problem yet?
 

Ryu

Member
Jun 22, 2015
37
1
8
did you fix your problem yet?
Temporary fix so far is just leaving the whole dome light apparatus removed, which seems to be working so far no dead battery, until I get some replacement light bulbs for it to see if that fixes it. Just waiting to get them and I’ll let y’all know.
 
  • Like
Reactions: 1 user

Ryu

Member
Jun 22, 2015
37
1
8
LMR has the best selection of stock bulbs for our foxbodies I just replaced all of mine for my 1991 LX 5.0 Coupe front and rear and they all light up beautifully.

and bought these headlight bulbs so much brighter now over stock.
That looks good I might have to do that cause on another note my headlight bulbs haven’t been replaced since it was made afaik, and they are pretty dim so they could use and upgrade. Next little project for sure.
 

Ryu

Member
Jun 22, 2015
37
1
8
As embarrassing as it may be it looks like the issue I was having was just a burnt out bulb, I got my replacement led some light installed for 2 days now and everything seems fine. The light works and I haven’t woken up to a dead car battery yet. I guess I never knew that a burnt out bulb could drain your car battery. Most importantly the car works so alls well that ends well I suppose.