Popping Fuses

[BigT]

Here's the short story:

Working on the front passenger door window motor I believe I overloaded the circuits and caused some damage. I was pulling up on the window (stuck) and using both up switches, drivers and passengers, trying to get the window up (much longer story as to why). Passenger switch got hot and I felt a little shock.

Now my #6 fuse in the fuse box keeps popping when I turn on the ignition. I've replaced it 5 time now. I have disconnected both switches and the right front window motor, but the fuse still pops (short somewhere).

I think I may have damaged the Window Safety Relay (Chilton's Manual), but the manual doesn't tell me where it's located.

Where is the window relay located? Should I be looking anywhere else to see what I damaged to fix this?

[BigT]

Fuse still pops after unplugging 4 different relays in the passenger's kick panel, but none of them look like what the relay should look like according to O'Reillys site. Still on the hunt!

[87gtVIC]

I believe on my 87 I actually have a circuit breaker especially for the window motors mounted directly to the starter solenoid.

[gadget73]

the circuit breaker is the power feed to the windows, the fuse I believe feeds power to turn the relay on. Sort of need the EVTM to diagnose this just to determine exactly what else is on that fuse.

[BigT]

I checked my 86 model, but could not find any circuit breakers connected to starter solenoid. Only fusible links. None of them look bad. I did find a circuit breaker in the fuse box, but it looked OK when I pulled it out. I did not try the fuse after though. Guess I'll try it tomorrow. I think I shorted something out. It's seem like the only thing that would cause a fuse to pop like that.

According to O'Reilly's I'm looking for a relay that looks like this:

http://www.oreillyauto.com/site/c/detail/BWD0/R250/01800.oap?year=1986&make=Mercury&model=Grand%2BMarquis&vi=1199415&ck=Search_power+window+relay_1199415_1152&keyword=power+window+relay

Still haven't found it.

[85crownHPP]

If it helps (if my 85 fuse panel is the same as yours)...

fuse #6 lists:
cornering lamps
speed control
AC clutch
heated back-light control
trunk release
police circuits
illuminated entry
power window relay
digital clock
tripminder
fuel tank filler door release

[85crownHPP]

My 85 evtm also shows the window relay in the passenger kick panel, a little down and back from two lock/unlock relays that are together.

It shows the power feed for the relay as a yellow wire with green hash coming from a circuit breaker on the starter solenoid.
The other wires for the relay are black, white/pink, and light blue/black.
So, if you find those colors going to a lone relay, there's a good chance that's it.

But, yours is an 86 - they tried all sorts of new and different things that year, so this info may not apply at all...(but wire colors should be the same, I'd think. They don't seem to change much)

[BigT]

If it helps (if my 85 fuse panel is the same as yours)...

fuse #6 lists:
cornering lamps
speed control
AC clutch
heated back-light control
trunk release
police circuits
illuminated entry
power window relay
digital clock
tripminder
fuel tank filler door release

Yep this is what I have. So I'm thinking that if the power window relay is shorted out that would blow the #6 fuse. Yes? No? And if I remove it and put in a new fuse and it doesn't pop, then I found the short...I hope

I remember yellow and red wires. For some reason I remember red with little blue dots. But I'm tired and could be hallucinating!

[sly]

I had this issue... the parking brake had crushed one of the cornering lamp harnesses and shorted that out. My car is not equipped with cornering lamps, but the harness is still there.

I'm actually not sure about the relay, but if the switch got warm, then you probably have a shorted switch now. This may also mean you have a shorted out power window motor.

[BigT]

Thanks for the tips! I'll check around the parking brake. So far I've disconnected the switches and right front window motor. Still pop's the fuse. I found this guy on YouTube (Scotty Kilmer):



I ordered the ECT2000 on Amazon for $122.00. I figured it would cost around $100 bucks to have a shop find the short, if not more. I also have a F-150 with an open in the starter wiring somewhere and plan to use it on that too. After two jobs I figured it will pay for itself.

[tjc78]

If you pull the passenger switch, does it still blow the fuse? You mentioned it got hot, I'm putting my money on the switch being shorted.

[BigT]

If you pull the passenger switch, does it still blow the fuse? You mentioned it got hot, I'm putting my money on the switch being shorted.

Yep, both the driver's and passenger's switches are unplugged and the fuse still blows. I also looked at the switch wiring harness, but every thing looks OK. No burnt ends.

[sly]

definitely NOT the switches then. could still be wiring somewheres (melted through and contacting metal) or one of the other issues mentioned.

[BigT]

Here’s an update. I have taken the dash apart and unraveled the wiring harness. I have traced it to a Pink/Lt Blue wire. It belongs to the back side of fuse #6. I traced all the connecting Pink/Lt Blue wires and unplugged any devices they are connected too. The short is still there. The only thing I found that was weird so far is where the connection plugs into the ignition switch has 3 melted ends. But these wires do not come near to the wire that is shorting. Or at least not near to any of the hand traced wires I followed.

Here are some pictures and a short video of what I found so far. I’m still at a loss and would appreciate any help and ideas!

[jaywish]

Do you have the wiring manual? If not you should get one for your car on EBAY. Ford used two, hand in hand, for electrical and vacuum. The EVTM which is a book and the Wiring diagrams themselves which are large lose-leaf pages. This will help you in the future.

Hopefully someone will post up with some specifics and confirm if you have unplugged everything on that circuit. That really is the best thing to do first.

I assume the fuse it out for the test.

If you cannot figure anything else out, this is what I would do. It is crude and heavy handed but works for my simple mind.

1) Make sure you have the appropriate size insulated butt splices either blue or red depending on wire size plus dielectric grease. Also buy a good crimp tool, not those crappy $6 combo everything tools. When you are ready to put it all back together, lightly fill the connector with grease before inserting & crimping the wires. I like to use liquid electrical tape to seal them after crimping, just in case. You could use the heat shrink kind of butt splices and eliminate the grease and liquid tape but sometimes it is hard to get in with a torch and not burn anything else.

A tool like this, make sure it does insulated, some only do non-insulated.
http://www.amazon.com/Channellock-90...hannellock+909
They usually have them at home depot.

2) Cut the shorted wire in the middle of the run. See which end has the short. Make sure to check both halves just for shits & giggles. Concentrate on the half with the short. Look at it closely for cuts etc.

3) If you can not find the short. Cut it in half it again to localize it further.

4) repeat as necessary.

5) when there are no more shorts, crimp it all back together.