'91 sidekick F1 fuse blowing

bushrat1 · 10-31-2009, 06:42 PM

I have a '91 sidekick 8v, 1.6L, 5sp std, 4wd, 4dr, canadian that is blowing the F1 fuse. I am looking to see if anyone has drawings for wiring harness routing and wiring schematics. I have disconnected all the connectors under the hood that are related to F1 and pulled the fuel pump relay. Still blowing the fuse. The only connections that I know of the I haven't pulled yet are the ones to the ECM. I am currently trying to trace the two blue/black wires that come from the main relay contact so I am open to any suggestions.

kick-fix · 10-31-2009, 09:50 PM

you did all the obvious tests.

ALL 91's will fail for ECU caps shorted. ALL.
pop lid, and see shoot.

easy fix.

send me a pm with real email addr and i will give you my full car 91 shematics.

but this will help a little here.
your correct Blue /Black is shorting to ground

http://www.kick-fix.com/ECU/91-95-TB...matic-base.jpg

the large can CAPACITORS all short, they dry out , split and leak,
blow out the bottom is top fail mode.
RUBYCON name is "death name" pure junk they are.

this page will show how to solve it.

My ECU is bad, now what?

bushrat1 · 11-02-2009, 10:41 AM

You can email me at bushrat1@hotmail.com

Bex · 11-02-2009, 02:10 PM

Would this have anything to do with ground connection at left rear tailight? This ground is for fuel pump, etc., and is notorious for being rusty. See common-failures

kick-fix · 11-02-2009, 02:39 PM

sure but , looking at all time takes lots of time.

first find out what dont work.

ECU?
Main Relay
Injectors dead or any not clicking
Pump pressure low or pump makes no sound at all?

but yes, all kicks need that 1 ground lug ,clean bright and the greased with
silicon grease . so it wont do that ever again.

left rear tail light.

runs pump and fuel level.

Bex · 11-02-2009, 02:53 PM

I suppose because I have to pay a mechanic to do stuff, I have tried to learn (thanks to this forum), to start with easy stuff first. F1 fuse blows, start simple, check that tail light ground that notorious for corroding. If your lucky, all may just be 2 minute fix. Reminds me of last year when the injector transistor blew in my ECU. It cost me almost $1000, mechanic searching everywhere, testing everything, loads of hours work. This wizard from this forum (who called himself jtgh at the time...miss that guy..) diagnosed my problem in 2 seconds, one shorted wire, two replacement transistors. All due to logic of where to look, start simple.

kick-fix · 11-02-2009, 08:17 PM

Actually this guy is on target and bad grounds would help in his case.

imagine the brushes in the fuel pump warpped around its little commutator.
now this motor is shorted. 0 ohm motor , infintate current device.
a bad ground to this pump , hides the problem.

he is doing the correct procedures.
pulling fuses, and connectors to isolate the overload path.
once end point is found , problem is easy..

pulling the pump feed conn. on the left kick panel is one such trick
killing the rear of car.

ECU shorted inside.
or wire chafe some where.

he alread pulled the engine bay feeds using the EFI schematic as guide.
the FSM has harness routing plans that make finding the actual paths ,easy.

hope that helps someone.

kick-fix · 11-02-2009, 08:18 PM

TOP fail for FI , blow is ECU. 90% but not all.

CodyJ · 11-03-2009, 12:10 PM

jtgh is kick-fix aka Jerry...

Check Grounds/ECU caps, wires aren't rubbing near firewall or anywhere else?

Goodluck!

bushrat1 · 11-03-2009, 02:16 PM

Here is the low down on the F1 fuse blowing. The car was running fine when I parked it and shut it off. I came back 40 mins. later and when I went to start it, it ran for about 4 secs. and died. I tried again and it did the same thing. Tried again only this time it won't even fire. I checked the fuel pump to see if it was running for 3 secs. when the key was turned on - nothing. I happen to have a test plug and jumper wire so I could check for spark directly from the coil - nothing. About a year ago I had the same situation - no spark and no fuel pump which turned out to be a burnt up ECU. About 10 mths. ago I was hunting when I hit a pot hole and the car quite. This time I had spark and no fuel pump, I was sure it was the fuel pump this time. So I dropped the tank and took out the fuel pump just to discover it checked out okay. Went to this wonderful site (should of come here first and saved myself alot of troubles) and Jerry's to find out the bad connections behind the left tail light in the connector. Cut out the bad connections and resoldered bypassing the connector. Car has been running fine till now. This time I went to this site & Jerry's first, got a schematic. Found out no CEL due to F1 fuse blown. Pulled fuel relay(grn connector) tried new fuse - blew again. Now I know it is the main relay(blk connector) Figured it out to be the blu/blk wire grounded from the main relay contact. I eventually found the ground to be in the harness along the intake manifold in the wire looms - there is 4 of them. Hooray the car is running once more. So far so good. Thanks to everyone for all your help, much appreciated.