Starting problem - electrical

[schnaarf]

Affer about 5 years without an e30, I'm now back in one. The good news, it's a black 325i Touring and the bad- few gremlins to sort.

Windows were only working when the door was open so swapped the relays in turn (no joy) then looked and checked (very gently) that the starter motor green/black wire was tight (it was, no joy). Gave up, decided to go for a drive but decided to try the Windows- they now work! But, now won't start. Only light on the dash is the battery light. Battery power is fine, lights work at full brightness but absolutely nothing when turning the key.

I'm guessing I've disturbed something around the starter motor area but none of the dash needles (eg fuel) do not move with key in any position.

Any thoughts on where to check?!

Many thanks

[Dlb26]

There's a walk through on the wiki page, I had a similar issue turned out I'd disturbed the dme relay removing an lpg system.

[Brianmoooore]

Won't start or won't crank? BIG difference.

[schnaarf]

Cheers for that. Went through it all and its suggesting the ignition switch. But when I turn the key I get 12 volts coming from the green wire on the ignition switch...

ICV buzzes etc

[schnaarf]

We posted at the same time.

It won't turn over

[schnaarf]

Any thoughts ?

[schnaarf]

Still no luck with this. ICV buzzes when the key is turned but nothing else. Silence.

Must be missing something obvious.

Won't start, crank, whistle, moan or anything but will do by jumping the 2 pins under the diagnostic port.

[Brianmoooore]

Fault is somewhere between (and including) ignition switch and the engine loom C101 plug.
Black start signal wire comes from the ignition switch to a multi pin plug and socket half way down the steering column, where it changes to black/yellow. This wire goes across the dash to a single pole plug and socket above the top right of the glovebox area, where the starter inhibitor relay on an auto transmission car plugs in, and from there up through the duct to the bottom of the fuse box, which it just passes straight through, and out to the C101 engine loom socket next to the fusebox.
Just to complicate things, someone may have added one (or more) immobiliser into the wire somewhere along the way.
Find the multi pin plug and socket under the dash, by the steering column, pull it apart, and use a short piece of wire to briefly link the red wire to the black/yellow in the half that heads across the dash. This should make the engine crank.

[schnaarf]

Many thanks for taking the time to reply Brian, much appriciated. Tried linking the red and black/yellow but got nothing... Guessing there is something wrong with the red feed?

[Brianmoooore]

but will do by jumping the 2 pins under the diagnostic port.

Will do what? Just crank, or start and run, assuming the ignition switch was on.
Red wire comes from the fuse box, where it is bolted to the red wire from the battery +, by the hex headed bolt visible on the deck of the fusebox.

[schnaarf]

First chance I've had to check- it runs beautifully starting with pins 11 & 14 but nothing on the instrument cluster works. The only light is the battery light just before it starts. The engine turns off when turning the key off.

So, must be a + wire coming from the engine? Are there any obvious places to start?

Really appreciate your help, I'll be making a donation to the forum.

[schnaarf]

Just to close this off- fuse had gone hadn't it. Ffs

[Brianmoooore]

Just to close this off- fuse had gone hadn't it. Ffs

There are NO fuses on an E30 that will prevent the engine from starting and running if blown, (except the in line fuse near the battery, only fitted to cars with the battery at the rear.)

[schnaarf]

Engine cranked & ran but only with the key turned then by shorting the c101 plug.

Just to confirm, it now starts fine with the key which it didn't until I replaced a blown fuse.

[Brianmoooore]

Engine ran but only with the key turned then by shorting the c101 plug

Then there's still a fault with the yellow/black start signal wire/switch in the car body looms, but it is NOT a fuse.

[schnaarf]

Ah! Could that explain why my blower fan doesn't work and the window switches are always live and illuminated when the car is off? Have to press the isolator switch when getting out of the car otherwise the battery goes flat after a few days. (Tested the blower fan and its fine, just doesn't work from the switch)

[schnaarf]

any thoughts?

[Brianmoooore]

Does the heater fan work on its switch if ypu hold the key in the start position?

[schnaarf]

Nope!