Starting Issues

[BackinBlack]

Hi, I have an '90 cabbie 320i (with a b25 engine).

Every now and then I have problems starting the car. I turn the ignition key and nothing happens, usually after a couple of tries the car starts up no problem. Sometimes though it takes popping the bonnet and the use of some wire - always looks a bit suspicious!

The battery is less than a year old and fully charged up. If I short the starter / use the diagnostic plug it starts up no worries - so I'm thinking its got to be an issue somewhere between the ignition key and the starter?

Looking at the wiki it suggests the problem might be the ignition switch itself.

How can I test the switch properly? As the fault is intermittent, I could test something that is the problem, but is working when I test it (if you see what I mean).

Also, can anyone shed any light on fitting a push button start temporarily so I can at least get it going without looking like I'm nicking it!

Thank you for any feedback

[Brianmoooore]

The wiring from the ignition switch goes to a multi pin plug and socket which should be clipped, in a stack with the column switch plugs, to a bracket half way down the steering column.
You are right that the ignition switch is likely to be the problem, and if you connect a 12 volt bulb between a good body earth and the black-black/yellow wire at this socket, you will be able to see the bulb light when you turn the key to start.
If it still lights when the car refuses to crank, then the switch is not the problem, and I'd start looking for a faulty immobiliser. If it doesn't light, and the dash warning lights remain on, then the switch is the problem.
Short the plain green to the black-black/yellow with a push button.

[BackinBlack]

Brilliant, thank you Brian.

Something for me to do at the weekend.

[Skinny89]

Hi im needing some advice to, im having the same problem with my e30 but i was getting it to start by crossing the red wire and the black wire at the back of ignition switch, but now wont start by crossing wires but will start at the plug under bonnet.

[BackinBlack]

I have now wired in a push button start following BrianMoooore's info above (thank you again Brian) -

From the bottom of the ignition barrel;

I followed the wires to its connecting block (cable tied to the steering column)

I then took the thick green wire's pin out of the block and attached a wire to it (and replaced in the block),

Then ran this attached wire to one connector on my button

Then ran a wire from the other connector on the button back to the black/yellow wire on the loom side of the block (its a single spade ended wire).

Its a bit of a fiddle getting to the block and then attaching wires, but it worked a treat

PS: To be honest the hardest part I found was it took me a while to realise that the steering wheel will not come off without the ignition key in !!

[Skinny89]

Haha i done the same even had pullers on the steering wheel lol, im in my e30 now with a button wired up to black/yellow and green still wont start, had a button wired up to black/yellow and red nothing even tho was starting with this the other day.