Tailight problem - Diesel Forum

remote · 12-29-2007, 11:02 PM

Have wiring problem, No Taillights. Have headlights and brakelights. Checked for current on taillight terminal but found none. Glitch is when light switch is pulled on completely I have head, turn , stop, but no tail. I can However pull light switch not completely out and sometimes get the tail lights to come on but not the head and tail at same time. Replaced the light switch with carquest # DS268 tonight but changed nothing. I had just replaced switch about three weeks ago from autozone. Anybody got any Ideas?
Thanks Remote

Snotzalot · 12-30-2007, 10:58 AM

Fuse.

Check for proper ground on the tail lights. Did you check the bulbs? Do you have brake lights?

Kaliburz · 12-30-2007, 03:41 PM

Weird.... a few months ago, I ran across a question similar on the Yahoo Ford question section.

So, when you go to the marker light position, first pull, do you have any lights at all? You should have the tail lights and marker lights. Second pull should just turn on the head lights w/out affecting the back. If no lights on the first position, check fuse.

I don't recall what type of bulbs you use (1157?), the ones w/ the two nubs on the bottom for contact (twist in type). Check to make sure the socket contact is 'springy' & to make sure the bulb is tight. Check for the ground contact in the socket (touches the little metal nub on the side of bulb.

Also, if you have a wiring harness for a trailer, make sure the wires are good and not grounding out. (I think that's what it was on that Yahoo question....go figure- poster said the wiring harness was it...)

Discbrks · 12-31-2007, 11:07 AM

I think the tail lights also run thru the turn signal switch.

cdnsarguy · 12-31-2007, 05:47 PM

Correct...... discbrks they do go through the MFS multi function switch.

Remote.. forwarded the MFS test to your email.....

remote · 12-31-2007, 09:26 PM

Truck is 1991 250. Checked the Tailight fuse and it was OK. Which and where is the wire leaving the fuse panel and where would be the places to check on the way back to the tail lights? All help appreciated.

Willie · 01-01-2008, 12:28 AM

Have you checked the plug / harness that connects to the lite switch behind the dash ?

Fozz · 01-01-2008, 04:39 AM

I second WillieTwo. Check the back of the headlight switch. Either the switch or connector might be fried. These switches have been known to do this. There is too much current going through the connector (especially if you have multiple running lights hooked up).

remote · 01-01-2008, 10:29 AM

Switch is 2nd in 3 weeks. That is why I feel problem is elsewhere. Plug/Harness does have burn sign so problem maybe there or between there and taillights because I replaced fried female taillight connector at same time I replaced light switch three weeks ago. Which Color wire leaves light switch and goes to taillights>

Snotzalot · 01-01-2008, 10:42 AM

Start checking things from the tail lights first and then work your way back to the switch!

remote · 01-01-2008, 11:08 PM

New Issue???? I can pull headlight switch out to the first position and no taillights.If I pull Switch slowly going to the second position I will get tail and dash lights to a point then they dissapear and the headlights come on but the tail and dash dissapear. Same thing happened with previous switch???

cdnsarguy · 01-02-2008, 02:10 AM

When you replaced the switch did you insert the knob stalk all the way and did it lock in...... sounds like it is just playing with you. Not sure if yours is a round stalk or a triangle does it need to be located correctly. WAG

Willie · 01-02-2008, 10:46 PM

Perhaps you have a trailer towing package where all the rear and marker lites run thru a small relay located on top of the driver's side fender. I think we need to start a poll for the tricky problem of the year award for 2008 [img]/forums/images/%%GRAEMLIN_URL%%/smile.gif[/img]

remote · 01-05-2008, 11:44 AM

Thanks for help!! Although switch plug had only small burn
indication there was serious melting way back up under the dash.
A real pain to get to. Clipped out melted wire and replaced along with switch plug as best as I could with new. All seems well now but noticed that the cluster lights will not dim.
Thanks, Remote.