5.0v81990f150

I just got home and checked,no running lights up front either

88xlt

That would certainly tell you something. What I'm not sure, possibly an overlooked fuse or relay. I wish I could read wiring diagrams, but they pretty much baffle me.

papa tiger

If you get power to all the light sockets than the ground is screwed up. Test continuity through your schematic to find the corroded splice. Once you find and repair, corrode proof and shrink tube it at the same time. There are wire schematics for it free on line.

95SWB

Daytime running lights module or headlight switch if you swear all your grounds are good all your fuses and relays are good all your bulbs are good all your harness conectors are good and no pinched wires under the bed. Diagram is below for all lights 88-90

5.0v81990f150

Here is the only grounds i know of, i recleaned them to no avail.





I replaced the switch and the pigtail,no difference





Clean new fuses,no change





I know you cant really tell but there is no corrosion on the back





I relifted the bed,only 2 spots that could pinch,and they are clear. I even wiggled the wires before doing so everything was free moving.

Other than that all bulbs are new,i just bought them, i tested for power by taking a multi meter and putting the probes were the bulb would be, i got a reading of 12.2 vdc, on all three metal connectors. Did I do this test wrong? I've retraced me steps like 100times now lol I'm losing my mind

papa tiger

Do you have continuity of the bulb socket ground to ground or is it open or maybe high resistance to ground. Check all your ground wires from each bulb to see if they have continuity to ground. Either all the sockets are dead or the grounds are/ is open. I would remove that ground terminals from the wires, clean up the copper to shinny and put a new terminal ends on them. They are wide open to all kinds of corrosive problems there.
http://cimg8.ibsrv.net/gimg/www.f150...6acea18287.jpg

5.0v81990f150

How do I check that? Ground side to frame...it should read 0 right not batt voltage?

papa tiger

That is what a VOM does. It will read Ohms to ground thru the wire. The cables have really gnarly looking terminals on the wires. Here is where the corrosion is hidden from you possibly. Just open up the terminals and pull them off the wire then clean the strands to copper clean color and clamp on new terminal ends. The picture I copied if magnifies shows what I am talking about. That lower cable with the tape around it looks strange also. Corrosion isn't always blue green in color. As resistance grows in a circuit it sometimes discolors where it clamps on the wire terminal not yet burning but this causes more resistance this happens over a great deal of time sometimes..

5.0v81990f150

Ok I'll give that a try when I get off work, why would it just now act up? I was all working prior to the work I did

papa tiger

A helper may benefit you some in tracing your continuities but I would do those terminals first. Remove them and see if one is open or there is resistance from the wire to the terminal eye. Saves some time here possibly. You should read zero resistance at these 3 terminal eyes back thru the cable. If your meter swings to infinity you have it for sure. I believe you are looking for the open ground circuit/wire, possibly from the multi function switch to where ever it opens/corrodes. Important thing is be methodical and exact. also the fuse block, you can test from the fuse holder back to the insulated wire past the connections with your VOM set on Ohms and car battery disconnected.