no power to accessories

[markjdinger]

I am not getting to power to any accessories. No spark when key is turned in ignition. Completely dead dash, no starter clicks.

Have checked battery, fuses. All normal Dismantled steering column. Put multimeter on ignition switch. Get 12+ volts on wire from battery. As soon as I turn key to Acc, ON or start, get 0 volts in all positions.

Suspect faulty ignition switch, but when I disconnect connector to ignition switch and try to hotwire car, I get same result (12 V to main line, 0 when I jump).

I can get starter to spin if I jumper across posts on the solenoid and bypass ignition switch.

Problem showed up with no prior signs of electrical problems. Just parked on day and woke to find problems in the morning.

'94 Sub legacy. AT.

I only have power to door locks, dome light, hazards. Anything that needs to have key in ACC is dead.

Not sure where to go from here.

[markjdinger]

Does anyone know whether a malfunctioning relay or switch would cause this problem? I get power to the ignition switch but as soon as I turn key it goes to 0 volts. If I disconnect the B63 connector and try to jumper power from the Black yellow wire (12 v) to any other wire in the connector is reads 0.

I'm assuming this is being caused by a short somewhere in the accessories.

Anyone have troubleshooting ideas.

[vrg3]

Yeah, it does kind of sound like a short circuit -- when you turn the ignition one, something's drawing sooooo much current that nothing else gets power.

That's kind of scary; if that's true, then that's a heck of a fire hazard.

You might try removing all the fuses in the car except SBF-4 and the fusible link. See if the problem goes away. Of course, the car won't start, but you can still measure voltages and/or see if the starter spins.

Then try putting in fuses one at a time until you figure out which one is causing the problem. You may have a bad fuse that should have popped but didn't, so it actually might be a good idea to replace at least the ATO ones that are cheap.

[markjdinger]

vrg3 - Thanks for your help. Great work on the scan tool, by the way...

I pulled all the fuses from under the dash. I get 0 volts after pulling every fuse, EXCEPT fuse 2. When I pull that one (windshield wiper/washer), I get 1.11 V to the ignition and the ACC.

So, it seems clear this is where the short is occuring (20 amp fuse, so maybe that is why it is not blowing?). Is it now just a matter of testing each wire to the wiper motor and washer motor looking for a break or wire grounding out on the ground?

Thanks again for your help in steering in the right direction.

[vrg3]

Thanks.

1.11 volts is still really low... Unless your battery is that low too? Or was it a typo?

You'd have to draw way more than 20 amps from a healthy car battery before its voltage would drop near zero (or near 1.11 volts, for that matter).

If the short is in the wiper circuit and you're lucky, it's in the motor or something else removable. If it's in the car's harness it'll be more painful to deal with. So the next step is unplugging the motor and seeing if the short disappears; if it does, just replace the motor.

[markjdinger]

It was not a typo. I get 1.11 V at the ignition switch when I pull fuse 2. I disconnected the wiring harness to the wiper motor and it didn't change anything.

Could the short be BEFORE the fuse, thereby not blowing it. It looks like power routes directly from SBF-4 through the RY wire into connector B63 on wiring diagram. Or should that blow SBF-4?

I'll grab the DMM and poke around some more trying to isolate. Any other ideas would be great. It is helpful.

[markjdinger]

Here is a little more info from this mornings readings. Battery 11.66 V. At the ignition switch (with all fuses pulled from under dash fuse box), I get 10.30. Doesn't make any difference whether wiper motor is plugged in or not, same reading. Get same reading in OFF and ACC position.

If I pull connector B42 out of fuse box, I get .72v at the ignition with key in ACC position. Same reading on the ACC wire at the ignition switch.

I'll charge battery this morning, as it is starting to drop.

VRG3 - I can't figure out what it means when there is line going to a box which reads FB-1, FB-2, etc on the wiring diagram. What does FB-1 mean. (Far right side of power supply routing diagram).

[vrg3]

Any fuse should pop with the current required to drop a healthy battery's voltage down that far. I don't get it.

The FB-x indications are references to other pages in the electrical manual. Every other circuit in the car gets its power from FB-something.

Wait -- did you not pull all the underhood fuses?

[markjdinger]

I just discovered the problem. The BY wire from the engine fuse box that supplies power to ACC was totally corroded in the fender well. Looks like someone in the past had a splice on it.

That is why no fuses were popping.

Thanks for all your troubleshooting help. Your suggestion that fuses should be blowing with that huge voltage drop led me to check the wires from the engine fuse box to the under dash fuse box.

Now, on to my knock sensor issues.....

[vrg3]

Wow. Nuts, man. I'm glad you solved the problem.