325 M/T starting wiring issue Essex

[jarques325]

Hi everyone, newbie and new owner of a 325i Coupe I’m trying to get back on the road. Trying!!
I have removed the carpet to have some welding done. It has run since but briefly. I removed the alarm thinking it’s plying up seeing that it’s old. She still won’t start. Turns over but main relay is dead. Presuming electrical. Does anyone have a E30 stripped with bare wiring to send me a video or can anyone recommend someone in the Essex area that knows these E30, any help will be greatly appreciated.

[Brianmoooore]

I'm neither in Essex or have any video that might help, but I do know my way around E30 electrics, so should be able to help if you perform remote tests for me.
Test equipment consists of a small 12 volt lamp of about 5W, connected to two short bits of wire.
Switch the ignition on, connect one wire from the lamp to body earth (terminal on RH suspension strut) and the other to the + terminal of the ignition coil. Does the lamp light?
Remove fusebox lid and remove fuse 11. Connect one lead of lamp to good body earth (rear bonnet bracket), and push the other wire into the inner socket of fuse 11. Crank the engine over. Does the lamp light?

[jarques325]

Hi Brian, I hope it’s Brian. Thanks for the reply. I’ll try that over the next few days and let you know. When I removed the alarm there was a white connected behind the glovebox I couldn’t find a home for and I suspect that might be part of my problem but I will start with the coil checks. Thanks again. Where about dare you?

[jarques325]

Drivers door has some sort of barrel presuming for an alarm, this I don’t have and or never had, what does that do? If anyone knows.

[jarques325]

Hi Brian, managed to get the E30 out again, I have checked the coil and it gets neither an earth nor a live, nothing on both wires, fuse 11 checked but I haven't got a bulb, I use a power probe, how is best to test?

I have also checked the main relay and it is not getting a signal earth, it does if I ground it to earth but it still doesn't start, only cranks over.

Any ideas if you have or can make any recommendations, after spending 4k on mechanicals I just want to drive it....

[Brianmoooore]

If there's no power on the + terminal of the ignition coil with the ignition switch on, then there's a break of some kind in the plain green wire that runs from the ignition switch to the coil.
Th wire runs from the ignition switch, to a plug and socket half way down the steering column, across the car behind the dash, to the immobiliser plug behind the glovebox, through the bulkhead behind the glovebox, up through the duct into the fusebox, and out (without connecting to anything inside the fusebox) to the C101 engine loom socket near the fusebox, and from there, through the engine loom to the coil, with a branch inside the loom to the ECU.
Since you've removed an alarm/immobiliser, check the plug for it that I mentioned above. It's a two pin plug with two plain green wires, one to each pin, found behind the glovebox, near the top. For the car to work without an immobiliser, there should be a plug connected to it with just a short loop of green wire between the two pins. If the immobiliser was dealer fitted, the plug and wire loop should be tied up to the loom nearby. Failing that, the plug on the old immobiliser loom can be used, which should have one plain green wire and a green/red wire. Cut these a couple of inches from the plug, and join them together to form loop.

[jarques325]

Hi mate, I actually replied yesterday but I am not sure where it went, anyway mate I only said yesterday that it must be great knowing what you know, the Green wire loop worked a treat, I have a spare loom I bought ages ago and knowing where to look now all I did is fitted the loop and it started, she moves and I drove her all but a few minutes, tell you what I seem to have although I remember this been the case before, it is the idling, on start up the car revs really high, as in over 4000 rpm it does drop down quickly when you blip the throttle but does go up the minute you touch the accelerator again, just l wondered if you know what contolls the idle?

[Brianmoooore]

Idle speed is set by the software in the engine ECU, and is increased slightly if the coolant temp. sensor says the engine is cold, and/or 12 volts is applied to the 'aircon. on' pin on the ECU.
The throttle butterfly, controlled by the accelerator pedal, is set so that with the pedal fully up, the engine would idle very badly at around 500 - 600 RPM or so.
The ECU controls the idle control valve which is plumbed across the throttle butterfly, so that if it opens its internal valve, it allows more air into the engine, exactly the same as if the throttle butterfly was opened slightly more, so increasing the idle revs.
The amount the internal valve is opened is determined by the ECU comparing the intended idle revs. with the actual engine revs. until they are the same.
First things to check are that the screw that sets the closed position of the throttle butterfly hasn't been 'adjusted' (look for burrs on the nut of the slot in the screw) and that the throttle cable isn't too tight, and holding the butterfly slightly open.
Next, check that the idle switch on the throttle position switch is clicking as soon as the butterfly leaves its stop, and that it is working electrically.
The insides of the ICV could possibly benefit from a clean with a throttle body cleaning aerosol, but sometimes they can stick slightly as a result of slight wear, but this normally only results in the idle being marginally higher than it should be.

[jarques325]

Hi mate, thanks again for the help, idle air control valve seems to have done it, bought a cheap one online to see if it will rectify the idling and it looks okay, I feel terrible asking questions but I do appreciated the help, hopefully some day I might be able to help you in return.

I have a a few things that have been popping up with use, firstly the triangle shaped clips holding the wiring in place running on the inside of the sills on both sides, where can they be found? Secondly my sunroof is dead, are they prone to fail? Lastly is the speaker wires, I cant seem to find them or a connecter?

Many thanks,

[Brianmoooore]

Answering (E30 related) questions is what the tech help forum on here is for, so ask away.
Part numbers for the triangle clips will be in the ETK somewhere, an may or may not be available from BMW. Never needed to buy any, so I can't help further on that one.
Very unusual for an electric sunroof to fail as in 'dead'. Quite common for them to stick shut if not been used for a while. Is it completely dead, with the switch not lit up?
Speaker wires, if fitted by BMW, are twisted pairs, so quite distinct from other wiring. I think the ones to the rear are supposed to run back the sill with the other looms, but they are dealer fitted, rather than at the factory, and I've found some running back the centre of the transmission tunnel.

[BenHar]

The wiring clips maybe on here: https://www.realoem.com/bmw/enUS/showpa ... Id=61_0533

Ben

[jarques325]

Thanks so much, I actually found those clips from Leebmann24.de thanks to those numbers!!!

[jarques325]

I have another question please, these two might be unrelated but I will try, I have a brake pad warning light on which I can assume is pads although they are new but one can assume the wear indicators are faulty or not plugged in somewhere, equally in the drivers kickpanel by the speaker (lower A pillar) there is a grey wire about the thickness of a TV antenna cable and about 8-10" long, unplugged. The plug is strange as it is a round plug about 1.5" long with very fine pins inside, reminds me of a 90's CD changer plug. Any ideas to what this might be, the irony is there was an old CD changer in the boot but not fitted,

[BenHar]

Best to post questions like this in the Technical section.

Pad warning is likely to be a broken wire at the front left or rear right.

Grey wire is to do with the factory alarm, I think.

Ben