electrical short??

[Bex]

I had originally made an appointment with my mechanic as I had a short somewhere in my 91 Tracker. It started with the radio cutting out when I put on the brakes, indicators or hit a bump. Then the brake lights stopped working completely. In the meantime (when it rains, it pours) my ECU went, so I've attended to that first. I just got my car back, having dealt with the ECU nightmare, and my mechanic didn't have time to look at the brake lights. But now I see that the radio stays on all the time, no cutting out...still no brake lights, and now indicators/hazards don't work either. Fuses and grounds are ok. Any other suggestions as what this could be? I'm tapped out from ECU repair, and would like to fix this myself if it's simple enough. Thanks!

[jtgh]

hi stranger !
radio is on CIG and Radio fuse and
brakes are on STOP horn fuse.
if the stop fuse keeps blowing then the brake circuit is grouned out.
if the fuse is good both lamps are bad.
but.. the emergancy flasher could be fouled up.
or the brake pedal brake switch could be broken.
also many cars have had someone add trailer wiring which is infamous for messing up the works. (opens and ground outs)

see next post
cheers

PS: readers, note this car has blown multiple ECU's 3 or 4. and was caused by injector short circuits (I think it is the wiring)
the Q101 transistor Smoked.
there is a brack light issue too.

[jtgh]

brake road map.

enjoy.

[gj68]

The radio in my '91 Tracker would go off. The problem was the fuse holder was not tight enough on the fuse. I bent the metal a little so it would put more pressure on the blade of the fuse. I haven't had any trouble since.

[jtgh]

that shouldnt happen , someone probably jammed a wire in there for a fuse and wrecked the spring action of the fuse circuit. PO's are great huh?

FYI:
she has a history of shorts , not opens.

( look for wiring hack jobs at both ends of the brake circuit)
1: trailer light is NUMBER 1 !
2: then up front where some dweeb thought he could wire in an alarm or something can couldnt or wouldnt use a road map , guessed and messed it all up.
both of these are very common.

look for evidence of old Alarm, Imobilizer, remote start hack in circuits.

wire nuts, twist wire and tape splices, buttplices (loose) and anything that does not look factory OEM fresh..

[jtgh]

some have 3 brake lite in spare tire bracket look for bad wires there or damaged light assembly.

[Bex]

Strange that you talk about immobilizers. I have one in the car that I haven't used for about 10 years (the key was getting hard to turn, so I just forgot about it). Do you think that after all this time it could suddenly create a problem?

[jtgh]

id ignore that and look carefully at the Red injector wire and its mate.
make sure now one played with the B8 REd wire at the injector
or the B17 at the ECU ( they are located togther at conn)
and at the other end near the injector , examine under bright lights, for any damage to the wires.

[Bex]

The B8 andB17 injector/ECU wires would only affect the ECU and injector, right? Is it right that they would have nothing to do with the other 'intermittent' short that I have had for the past few weeks? So this would mean that I actually have two unrelated shorts in the car? Is that right, or is it possible that the short in the ECU wire could actually affect something else. Actually, now that I think about this, this whole thing may have started quite some time ago. Last year (or longer) when I would hit a bump or something, the fasten seat belt light and buzzer would go on. It would go off after about 20 seconds, so I thought nothing of it. Months later, the radio started to turn off when I used an indicator or put on my brakes (or sometimes windshield wipers). Then my brake lights stopped working completely. Then B8 wire in ECU seems to have a short. Then indicators stopped working. All related or separate problems??

[jtgh]

IF B8 shorts ,the transistor then starts getting real hot.
then the ECU overloads the 12vdc power buss to the ECU , which could in fact blow the fuse to the ECU and kill car as a result. (if not the transistor roasts)

it is best to trouble shoot the electrical problems 1 at a time. starting from the most
important to the least ( only you know that ) but in this case car doesnt run, so brakes lites are useless.

I would bypass the B8/b17 wire pair. if it were mine. ( not worth the expense of blowing a 4th ECU , (count?). IMHO.

getting a new wire pair would shot gun that problem for good.
then you could concentrate on "IS my Injector good or bad ?"

0.8 ohms to 1.2ohms ( not even a tad less , than 0.8 ohms)

the nicer meters Like (Fluke , Washington grown) has low ohms range perfect for measuring low ohms.

ALSO:
some shops have an injector tester.
and all injector cleaning services have a full analysis of the injector just before the cleaning service.
they never clean a bad injector.
so one other alternative is to remove the injector and send it out for professional cleaning. (they did mine here for $20) .

then if it comes back , you know it is not shorted.
they run profiles on the injector for flow , mine had a flow of 456cc/min after cleaning. < data point , no where on earth !

my injector looks exactly like this on a scope:

http://carfix.stufftoread.com/INJECT...ors/my-TBI.JPG

notice the fancy modulation !

Your car is old, having more than one electrical problem is common.