Weird 1986 930 problem

[Ringnalda]

Got the car running today, battery was flat so I blamed the trickle charger for not working. Charged battery, and when I connected leads I could hear an oscillator in the engine compartment. Started the car, went for a drive, all OK. Got back, switched the car off. Went to re-start, engine just spins but doesn't fire. Put charger back on again, there is a significant draw on the battery even with the ignition switch off. Suspecting a faulty ignition switch, I disconnected the ignition switch but I still have a draw on the battery when I connect the terminals. Haven't pulled all the fuses yet, did take all of the relays out and the problem is still there. Could it be a bad diode in the alternator? When I try to start the car, my tacho jumps all over the place but when the car runs it is fine. Any advice/help suggestions appreciated,

Jan

[ant7]

Sounds like you have an Alternator Fault! did you disconnect the battery positive before putting the battery charger on ? if not, then you may have damaged the Alternator!
Hope this helps.
A...

Originally Posted by Ringnalda

Got the car running today, battery was flat so I blamed the trickle charger for not working. Charged battery, and when I connected leads I could hear an oscillator in the engine compartment. Started the car, went for a drive, all OK. Got back, switched the car off. Went to re-start, engine just spins but doesn't fire. Put charger back on again, there is a significant draw on the battery even with the ignition switch off. Suspecting a faulty ignition switch, I disconnected the ignition switch but I still have a draw on the battery when I connect the terminals. Haven't pulled all the fuses yet, did take all of the relays out and the problem is still there. Could it be a bad diode in the alternator? When I try to start the car, my tacho jumps all over the place but when the car runs it is fine. Any advice/help suggestions appreciated,

Jan

[T77911S]

with the key off check for the sound in the engine bay, that should have been a given.

its either the frequency valve or the CD is on.
under the car would be the fuel pumps.

[Ringnalda]

So in troubleshooting this a little further, when I tap the ground connector on the battery terminal, I hear a relay clicking, and upon further inspection it is the aux blower relay. I don't think I have a blower back there, but could a temp sensor be bad? And the relay cannot give the high pitch electronic noise (oscillator) which I can only assume to be a frequency valve? Thanks for the suggestion of the alternator, I guess will disconnect that next and see, but even if the alternator is bad does that explain a no-start?

[T77911S]

no, leave the alt alone for now.

if th esound is in the engine bay go listen at the left side where the CD unit is. its a grey box with cooling fins on top. pull the relays on the panel back in the engine bay and see if it stops.

not sure whay aux fan relay you are talking about. is it in the front trunk or the rear?

tighten the battery terminals. dont let teh tapping confuse you. that just means the connector is making a connection.

if you have a test light you can remove one of the terminals at the battery and connect the light between the cable and the battery. when the light goes out, you found your drain.

[Ringnalda]

Ok with the battery connected, and ignition switch off, I have hear an electronic noise coming from the left side of the engine bay. Sounds like it comes from the silver box but tough to pinpoint. If I yank both the 'easy' relays out, the tall fuel pump cutoff one and the round one next to it, the noise stays on. The next relay (smaller of the two) is a silver square relay (this one clicks when I connect the battery). I have to undo a bolt to pull that one, same for the next one which is bigger and if for the rear window defrost, also held in with a bolt. The small one that clicks when I connect the battery is described as an aux blower relay...

[Ringnalda]

When I pull the next relay (930.617.117.01) the noise stops... In online manuals the position for this relay was labelled aux blower relay which threw me off, after checking this is the relay that powers the CDI... Is it not releasing when the ign is switched off, which causes the battery drain problem, but will that give a no-start?

Jan

[ant7]

There are only a few things still powered up when ignition switch is off, the main obvious one is as i stated earlier, the Alternator, however, lights will work without ignition, and from memory, the aditional Air blower in the engine bay [my 3.2 has this] will stay live for a short time after the engine has been switched off on some models to assist in the engine cooling etc, however, the fault you have could just be a relay that the contacts have stuck together due to high current drain, and when the ignition is switched off, the high current contacts inside the relay [which on some circuits are always live] are still connected!
I had this with my 3.2 on the horn, i woke up one night to the sound of what i thought was someone blowing they're car horn, when i went outside, i realised it was coming from my own car! i had to pull the relay before it would stop! shook the relay a bit, put it back in and all was fine, so' if its not a diode fault in the Alternator, it could just be a stuck relay!
A...

[T77911S]

that relay is the delayed power off relay for the CD unit. the cd unit is the silver box with the black sticker on it.

it could be the relay or for some reason it could still be getting power.

pin 30 has power form the alt.
pin "S" is from the ignition. that should NOT have power with the key off.

i have never messed with this relay. if there is no power on S you could try taking it apart and resoldering the pins on it. you might get lucky.
also would not hurt to sand the contacts with a fine (600) sand paper. (if there are any).


all this relay does is keep the ignition on for a few seconds after you turn off the car to burn off fuel.

[Ringnalda]

No power on S. Only power on one leg... Have taken the relay apart, looks OK. Only a diode, capacitor, transistor and a resistor in there with the little relay switch itself. I'm just wondering if this relay staying active for some reason will give the no-start though??

[Ringnalda]

Reinstalled the relay, tried starting, no spark. Does it sound like maybe the CD unit has pooped out?

[T77911S]

you need to check for power at the CD unit first.

[Ringnalda]

It must be getting power. With the amount of noise it is creating I sure hope it's getting power, otherwise the mice have installed a wheel with a dynamo...

[T77911S]

if the CD is getting power and you have no spark it is either the CD or the coil...with a slight chance it could be the coil in the dist.

did you check for spark out of teh coil?