All interior lights not working

[AnnDixson]

I found the fuse for the interior lights and when I try to replace it it sparks, so I have a short somewhere. Any ideas on how to track down the short? My map lights, dome light and cargo light all work off this fuse, so no interior lights for me until I find the short.

 

[Jeff_Birt]

Usually, I try to divide the system in half, find which half the short is in and then do the same with that half. Most cases it winds up being from a wire rubbing through or a shoddy previous repair, i.ie wires just twisted and taped together, poor body work, etc. Look for chafing and/or green crusties from corroding wire. Shorts to ground can be tough to locate.

 

[bronco2fan]

Disconnect negative battery cable first. Put fuse back in, start checking for continuity at the furthest point. You may have to drop the headliner to ensure no wires are frayed or broke.

 

[JerryC]

If you want a common place to check first, the dome light.
Check the head light switch and plug for melting. The dimmer in the headlight switch might be bad.

 

[Uncle Gump]

I would start a headlamp switch also.

I've seen more then one that seen to much heat and melted

I'll post some dome lamp schematics in a bit...

 

[Uncle Gump]

Dome lamp only...

Dome/cargo with lamps on warning...

 

[AnnDixson]

The dome light where the bulb goes in is burned out

 

[Uncle Gump]

The bulb is burned out... or the lamp housing is burned?

If it's the bulb... that won't pop a fuse.

If it's the housing... fix that and see if it fixes it.

 

[AnnDixson]

The housing is burned out.I bought a replacement light housing and a new bulb, do I just install that and hope it does not burn out the new one?

 

[Uncle Gump]

That's about all you can do...

Those bulbs get hot... after 30+ years... shit haopens.

 

[Uncle Gump]

The housing is burned out.I bought a replacement light housing and a new bulb, do I just install that and hope it does not burn out the new one?

Actually... disconnect it. Then put a new fuse in and see if it blows.

 

[AnnDixson]

Still searching for the short to my interior lights. Thanks for the photo of the wiring diagram, that helps.

 

[AnnDixson]

Does anyone have the 4x4 switch housing complete with electronics?