4 replies to this topic

[Renegade]

Howdy Folks

New here & glad to meet everyone! Hope someone can help me out.

I've got a electrical gremlim that has absolutely stumped me. My pristine 79 F150 2wd which has been in the garage for at least 15 years has a glitch.

If you open the door the dome & courtesy lights dont come on (new switches already) - with the ignition key put to RUN & the heater control slid to the A/C position & with the door left open - you can hear the AC clutch engage & blower fan on its lowest setting run & the dome & courtesy lights will then come on & go off when you shut the door just like its supposed to all the time.

I've got the cluster radio & most all else out looking for any crossed wires bad grounds & so on but all looks in good shape.

Any guidance would be greatly appreciated!

Cheers

[johnfacundus]

Howdy Folks

New here & glad to meet everyone! Hope someone can help me out.

I've got a electrical gremlim that has absolutely stumped me. My pristine 79 F150 2wd which has been in the garage for at least 15 years has a glitch.

If you open the door the dome & courtesy lights dont come on (new switches already) - with the ignition key put to RUN & the heater control slid to the A/C position & with the door left open - you can hear the AC clutch engage & blower fan on its lowest setting run & the dome & courtesy lights will then come on & go off when you shut the door just like its supposed to all the time.

I've got the cluster radio & most all else out looking for any crossed wires bad grounds & so on but all looks in good shape.

Any guidance would be greatly appreciated!

Cheers

[johnfacundus]

Running down a cross feed can be long and difficult getting thru a wiring loom.This is what I would do. Get out your owners manual to locate the fuse for your dome and courtesy lights. Use a test light to see there is power on both sides of the fuse with ignition key off. Both sides should be hot as this circuit is always energized. If only one side hot replace the 15 amp fuse. Both sides must be hot. If both sides are hot remove the fuse then remove the two screws retaining the fuse box. Locate the hot out to the users. Get a jumper wire and connect to 12v then on the back of the fuse box connect to one of the fuse wires. Now try your door lights. If does not work connect jumper to the other terminal wire behind fuse box. Try the door lights again. If they now work the other terminal will be the feed wire. Can you connect a new wire there behind fuse box if not locate the wire in the loom just outside the fuse box and peel it to expose the copper. Connect your hot jumper to it and replace the fuse and try the door lights again. Should work. Cut the feed wire from the fuse box.Connect a new wire to the wire entering the fuse box. Now the other end of the new wire needs constance 12v. The best place for this connection is on the Batt terminal of the ignition switch. Other items are connected to this source like glove box light, cargo light, cigarette lighter. Are they functioning properly? Good luck!
John
PS A/C running on low blower will keep evaporator from freezing up

[Renegade]

Got it going (almost complete)many thanks for the help one side of the fuse block was bad - the fuse was good but after pulling out the fuse I noticed the tabs were very loose & sloppy - after a quick repair thats all in good order - now the hardest part finding the back feed.

Got as good hunch tho as I see a wire at the firewall going thru a grommet that looks as if its pinched at the firewall/heaterbox area & the wire next to it is power to the dome light - now just to get time to fix it

Thanks Again!

[BlackFord77]

I guess the moral is -whenever running a wire make sure it can't get it's casing cut or burnt easily.