My Power drivers seat fuse keep blowing. As soon as I stick the fuse in, it pops. I've inspected all the wiring and can't find an obvious short. Under the dash it is a bit of a rats nest as a previous owner installed some sort of an alarm. I have a multimeter, but I don't know how to proceed. I have wiring diagrams for both the Pedal Adjustment and Drivers seat. I'm weak with electrical trouble shooting so I'm looking for some tips. So far I know:
- The fuse obviously has power (blows a fuse immediately upon insert). I have not checked the AMPS or voltage there. Not sure what, if anything that would tell me.
- With the battery disconnected, I have continuity at the fuse (multimeter on the 2 prongs with the fuse pulled). I would have thought I wouldn't thinking that there is a short, yet there is power there.
- The green power wire to the seat and pedals is difficult to trace as it is in the main harness. I did the best I could under the dash and it appears fine (where I could see it).
- I checked continuity at the connector for the Power Pedal switch. With the red probe on the green power wire, I got continuity on all the other ports except the 2 that go the the pedal motor. I'm thinking those are switchable and would need the switch installed to test those. I don't thing the problem is with the Pedals though.
- I lifted the seat and visually inspected all of the wires and connections. No problems. This was before I had the multimeter so I need to get back under there and see what I can find from a continuity perspective.

Anyone with electrical expertise that could offer some help/suggestions? Like I said, I'm weak with electrical stuff, but if I get pointed in the right direction, I should be able to solve the issue. Basic troubleshooting tips are welcome.

Thanks!

 

What fuse number is blowing? What year and model is this truck? The first thing to do is get under the seats(if that's what the diagrams say this fuse serves) and unplug the seats and see if it still blows.

 

Its a 2001 F150 SuperCrew. I did try that when I had the seat pulled. Unplugged the motors and the fuse still blew as soon as I stuck it in.

 

Are you positive that there is NOTHING else tied to the same fuse? If not, the short to ground is somewhere between the fuse and the motor plug. Might be easier to run a new wire to it.

 

According to wiring diagrams the Power Pedals and Power Seat are on the same circuit. There are a bunch of wires under the dash that have been tapped into, but from my tracing so far, it does not appear that any of the wire colors for the components in question are tapped.

I'm liking the idea of a new wire. But tell me if this would tell me anything. I'm thinking of checking from the fuse to the Power Pedals and then the seats for continuity. Which tab of the fuse would I check from? I'm thinking if I don't have continuity to either component, then the short may be under the fuse box or something (at least that would tell me if it is before, or after the splice.

If I choose to route a new wire, would the recommendation be to use the same fuse, making a new connection at the fuse box, or one of the empty fuse locations?

 

Which fuse is blowing? What number is it?

 

It blows the 30AMP fuse #112 in the box under the hood.

 

According to the diagrams, that fuse feeds the switch for the power seats, and also feeds the switch for the adjustable pedal power. You may need to look at the adjustable pedals and try unplugging it.

 

Thanks, that is something I have not tried. I'm sure there is someway to check this with a mutimeter instead of fuses that cost $4 a pop. I did check the voltage at the fuse and it was 12V. I have not checked for continuity between the poles. I'm thinking that I would probably not have continuity in the current state. If I unplug the circuit that has the short (i.e. the pedal switch) then I'd have continuity at the fuse, right? Like I've said, I'm weak with electrical stuff and need guidance on what to look for.

 

One side of the socket for the fuse should have power with the fuse out of the socket. That's the input from the battery.

The other side of the fuse socket is the load going out to the seats and the pedals. Put yuour meter on ohms and touch the meter leads together. This is the reading you will get for a dead short(near zero) since both meter leads are touching together. Then take one meter lead and put it on the load side of the fuse socket, and put the other meter lead to a good ground. See what the reading is. Problem with this is you really don't know what a good reading is and what a bad reading is. If it's near zero, then we can safely say that's a bad reading. But since it's such a heavy(30 amp) circuit, some other reading like 10 ohms may be good, or may be bad, you just can't tell unless you read it when everything is working.

 

OK, I've pretty much tried everything. Unplugged the pedal switch, seat switch, motors and it still blows the fuse. I going to run a new wire. I'm just looking for verification that what I am thinking of doing is OK.

I pulled up the Power Distribution Box and it will be easy to splice into the green wire under the box, enabling me to use the same fuse location. I'd rout the wire through the firewall where I would splice in another wire using one of those T-connector things to run to the Pedal switch, cut the wire near the switch and splice it in, then do the same thing at the seat switch. I'd solder and use heat shrink on all the splices (except for the T-Splice). The wire looks pretty hefty, so I'm thinking 10 gauge. Is that right for a 30 AMP circuit?

I've spent too much time trying to find the short as it is. I just want to get the stuff functional and this should do it. Anyone see any issues with this?

Thanks

 

It works now. For the first time since I have had this truck, the seat and pedals now. I just ran a new wire as described above. The pedals were stuck in the up position. Much more comfortable now that I can move them down (I'm 6'4"). The seat moves up and down fine, but not back and forth. Just makes a rumbling noise (motor working, but not engaging). Anyone had on of these motor assemblies apart? Could it be that the gear has just slipped out of place, or am I looking at stripped gears. Any know if the gears are metal or plastic? I'm thinking metal as it is quite a load to move.

 

Never have messed with the motor assemblies. I doubt you will get much info unless a tinkerer has posted it on the internet. The dealer charges too much per hour to mess with stuff like that, they just change the whole thing out. And don't be surprised if it does have plastic gears. Everything is cheap and light as possible, just enough to do the job.

 

Found a post in another forum where the guy had the same thing happening. He took the motors off, cleaned up and lubed the track and it fixed it. Will give that a shot.

 

Cleaning and lubing did no good, still no joy. Something internal slipped out as there is a little split on the bottom of the motor case that moves when I move the track with a pipe wrench. These motors are not made to be serviceable. Thought about taking the motor apart, but since it moves up and down now, I didn't want to take the chance of messing that up a well.

I was lucky to find another seat track and motors at a salvage yard for a decent price. Once I install that, I will probably take the broken motor apart, see what makes it tick and see if it is fixable. Might help someone else in the future should I discover something.