924 electrical system, stuck in ACC mode

[reallybigbadbob]

ok, going to the battery, there is ofcourse the big red cable, and then 2 smaller red wires, and a blue and red wire. This seems normal, but even with the ignition wires disconnected, the radiator fan and fuel pumps keep running, the only way to shut them off is to disconnect the battery. Now, to try to figure out where the problem is, i disconnected the wires from the relay board, and the proper relays, still, one of the wires turn on the fan. I'm at a loss here, any help would be appreciated, and yes, i have the haynes book, and have retraced them, but cannot figure out what the issue could be.

[reallybigbadbob]

it's a 1980 931, sorry forgot to mention that.

[ideola]

Have you replaced the ignition switch? They are notorious for going bad on these cars. $5 part and a 30 minute job to replace. If you haven't personally replaced it, I'll bet a dollar to a donut it's bad.

[reallybigbadbob]

i don't think that is the problem, i have it completely disconnected. I did pull the fuses for those two circuits, and they are shut. i could toggle switch it, but i would prefer not too, nothing else is turning on when it's like that though, only the fan and fuel pumps. So, it has to be a hot lead turning those on, but no clue which one or where.

[ideola]

What you describe is one of the failure modes of a bad ignition switch. Key removed, but ACC stay on. The only other option is a stuck relay, but if you've pulled them all, that would rule it out. There is a fan switch relay that is part of the A/C circuit. Maybe it's stuck? It's usually attached to the heater core plenum, not in the fuse block itself.

[fmartenies]

If you can unhook the wires to the ignition and manually make the connections the switch would normally make and the car works properly then it is 100% your ignition. That is as simple of a test as you can do and fool proof. Expanding your search to other wires before isolating the problem in what you already have taken apart is a very bad idea. I have gotten many nice things on Craigslist for a song and a dance because of that.

[reallybigbadbob]

Yeah, I got this for a steal, the haynes book doesn't say anything about the ignition switch, and I couldn't find too much online about fixing it. There were also some shorts in the system because the guy rewired it to make it work. So, I had to go through each thing to make sure they were hooked up properly. Everything works now, unlike before, and i have 40 extra feet of wire that the previous owner threw in there. Honestly, people should just fix stuff right the first time, so much easier to make future repairs.

[fmartenies]

If it weren't for idiots we would all pay full price. Look at the wiring diagram in Haynes you should be able to see what connections should be made. An ignition switch is nothing more than a slider switch with a lock cylinder in the way. Electricity aint complicated, just tedious.

[924RACR]

What they said - try unplugging the ignition switch first, before counting it out. We've all had 'em fail, it's like a $10 part.

If not that, then possibly more serious issues with the fusebox, they can and do happen, but are far less likely.

+1 to fixing $hit right the first time...

[reallybigbadbob]

yeah, it was still doing that with the ignition switch all the way unplugged.

[reallybigbadbob]

well, dan, you owe me some donuts or something, got the new ignition switch in, and same thing. Everything looks like it is connected where it should on the relay board, so, i'm just going to end up toggling it. Luckily, I only paid $600 for the car, no rust, runs solid, turbo is in good shape, interior is almost mint, but I do need a few parts, rear body panel, rear bumper and left rear quarter panel. Drivetrain is in pretty good shape.

[fmartenies]

Think about what you are saying. It didn't work, so you replaced the switch. It still didn't work, so you are going to replace the switch. Either your car is magic or there is a huge communication gap in what you are telling us. Either way I wouldn't hold my breath for that donut.

[reallybigbadbob]

the new switch worked, but did not fix the problem. Sorry, I was not very definitive in my choice of wording.

[fmartenies]

Right....the switch isnt the problem. What will th etoggle switch do differently?

[reallybigbadbob]

it keeps the radiator fan and fuel relays from running whenever the battery is connected

[ideola]

Have you SYSTEMATICALLY checked all of the relays? Have you located the aux fan relay? Hint: it's not on the fuse block.

[reallybigbadbob]

where in god's world would they put that?

[ideola]

As I mentioned at the outset, there are two relays not on the relay board: the one for the radio, and the aux fan relay. These are usually under the dash and clipped to the heater box, although who knows what the previous owner did with them.

[reallybigbadbob]

under the passenger side dash? i know the other fuel pump relay has a clip to be mounted on something, but was just tucked behind the center console.