Hello. Please be patient with this novice. I've determined all the fuses in the power distribution box and within the cab fuse panel, connected to the left power windows are good. There is no voltage coming to the motor, even while wiggling the harness coming through the door hing or coming from the motor, switches, etc. I tested this with key on, with and without engaging the auto switch. If done correctly, where do I look next? This is very difficult because the Hanes doesn't even match wire colors I have on the motor. I have red and yellow. Hanes shows org/blk and wht/blk. Please help.

ETA: at first driver's window had difficulty going up and down then soon after no windows work at all from any switch.

 

Is it just the master switch that's dead or do no switches at any door work? I have found many times it's a broken wire in the drivers door jamb. Take that boot and push it back into the door so it's out of your way. Inspect the wires for breaks or brittle spots. If thats not it, its just gonna be a matter of tracing down wires until you find the culprit. And don't neglect to check your grounds.

 

Applying external power to motor allows the left window to work. Applying that power to the master switch allows operation of all three other windows but not the LF. I've pulled back the door jam boot and don't see an obvious problem there, but it's really hard to see. I'm not sure how to go about checking wires, since I don't have a circuit finder and don't know where to access the beginning of each line so I could use a multimeter. Any idea? One manuel I saw online said the main ground is under the seat. Is that true on this vehicle? Thanks for your reply

 

I'm leaning toward a bad ACC Delay Relay or the driver's windows switch since the power first goes there, then to the other 3 switches. Here is the 1999 diagram which might help you.

 

Thank you, Alloro. I'd seen this while searching the web but couldn't tell if it was for this vehicle. It looks like the former owner has changed the motor wires. When I get access to the vehicle tonight I'll look further. Thank you much.

 

But if you have no power to the switch you need to start there. Find that wire in the door jamb. You don't need anything but a dvom to diagnose this. You can set it for ohms and check for continuity. You'll need to cut off the tape that's holding them together so you can sort through them properly.

 

Thanks, Sycoholic. During the short time I had access to the vehicle I rechecked the 15A fuse 14-Accessory Delay Relay (power windows), Relay 4-one touch down and relay 5-ACC Delay, which all appear fine.

• I tested for continuity on wires 1-Grnd-Black and 2-Acc Delay Power feed-Lt Bl/Blk, switches in all positions. All were good except Auto Up, closed circuit when should have been open. I think that is 5-Grey wire-master control One Touch Command to Gem? (Ground wire to door Ground showed continuity)
• Checking at rest, 4-RF Dwn output to 3-RF up output, showed open when should be closed circuit.
• Again at rest, 5-Master Ctrl one touch down command to GEM open when should be closed.
• LF window circuit 2-ACC Delay Power Feed and 6-master window down control command to GEM input-tan/lt bl showed closed when down pushed, which is good but, also closed when in up position.
• LF window circuit 2 to 7-master window ctrl up command to GEM module input-WH/Blk on up is a good closed circuit.

The vehicle is gone again so I'll have to look again at hinge area later. But I did find where insulation had been nicked and taped on the terminal 4 wire, the White/Yellow, where the bundle was hooked to the door. I took the tape off, cleaned the nicked area with alcohol, taped back up and got a good reading on one of the checks, that was bad before. It think it was to the ACC delay Power Feed wire, #2.

 

For others that might be reading this, it looks like the schematic attached above isn't for the 1999 Ford Expedition 5.4 4x4, at least not mine. The receptacles have the function printed inside and the up downs are opposite of the schematic. Ex: schematic says Tn/LB wire is LF window up but it is the down control command to GEM input according to my master switch.

I looked closer at the hinge area inside the boot and I don't think it showed a problem directly related to the window power. All of the larger gauge wires look fine and don't seem to bend sharply when I manipulate. I see some small wires that appear to be melted to a small black wire. At first I thought it was solder, the way it reflected light. But after the sun got to a different position, it is very shiny black and about the same size as the small black wires going to the lock and mirror. It is melted to pink/tan near the door and to green and LB/Rd near the body. The wires involved could be going to the mirror but that is working well. They are likely going to the door lock. None have been working. But, this wouldn't affect the switch wires, would it? (unless there is some melting to the power line I can't see somewhere along the way)

I also checked to see if there was voltage to fuse 14 and there was over a volt when testing with from ground on the door to terminals on top of the fuse, key off. Did I do that right or should it have been both probes to the fuse?

Anyway, it looks to me like it is a wire problem hidden either in the harness within the body going to the relays or GEM, or somewhere else I can't see.

 

Maybe this can be of better use for wiring http://www.bbbind.com/free_tsb.html

 

Thanks, Sycoholic. It is the same as the other one. Strange, it doesn't match. I might think it is only because someone replaced and did it differently but the fuse panel diagrams don't match the owner's manual either. That diagram says #14, a 15A fuse inside, is the vehicle speed sensor but my manual says it is Power window Accessory Delay Relay, along with rear wipers, running board lamps, battery saver relay, interior lamp relay. It is a fuse though, not a relay??? I made sure to select the 5.4 engine in case their were differences. It looks like this is not an easy fix.

 

I would go with whatever matches your vehicle. If the diagram says fuse, and your truck has a fuse there, go with that. Maybe the manual is wrong.

 

If you have ANY wires melted together separate them from each other first. Then I would use a test light (make sure that you have a good ground for the small clip) and check for power to the master switch. By the wiring diagram above it should be lb (light blue) and bk (black). All of the windows are powered from the drivers door switch so if there is no juice at the main switch then none of them will work.
Since you said that the problem came in stages either there is no power to the master or the master switch is kaput (you did check to see that the window lockout switch is not set on didn't you?)

 

Yes I did. Thank you. It looked pretty bad under the dash so I think there could have been a problem due to a leak somewhere. Actually the vehicle recently started blowing black smoke then died completely so we sold it for parts. So, consider the problem solved, LOL! Another one bites the dust.