Car won’t start - battery fine.
Discussion
ian332isport said:
I found this picture of an E36 318is engine loom...
Latest installment...In the pic that you've posted there is, as you pointed out, a chunky cable which separates into three. One goes to the diagnostic port, the other two go to two separate plugs, X20 and X69.
On mine, the chunky cable "1", only separates to two smaller cables.
"2" goes to the diagnostic port and "3" goes to the oblong unit that's mounted on the strut. I believe this is the ignition coil.
The boot on the plug at the end of cable "3" does contain a yellow wire, but I can't tell if there's a thin black stripe on it. I certainly couldn't see one but I'll admit that I couldn't look all round it without pulling at things and risking breaking something.
Edited by MitchT on Thursday 17th June 21:28
Still scratching my head with this but did make an interesting discovery tonight...
I read that if you turn the headlights on and they dim when you try to start the engine, it's the starter motor or solenoid that's the problem. If the lights don't dim it's a bad earth somewhere. I tried and the lights didn't dim. What I did discover in the process is that the nearside sidelight isn't working. I took the bulb out to replace it but on close inspection it's clearly fine. As an experiment, I swapped it with the offside sidelight bulb. Still the nearside sidelight wasn't working, so the bulb is fine but the sidelight doesn't work. Could this be part of the same electrical issue that's stopping the starter motor from working?
Also, I noticed some corrosion on what I believe is the earth strap where it connects to the positive battery terminal - see pic below. Could this be a part of the problem? NB. Ignore the yellow crap in the pic - that's the foam from the padded battery jacket that's disintegrating.
I read that if you turn the headlights on and they dim when you try to start the engine, it's the starter motor or solenoid that's the problem. If the lights don't dim it's a bad earth somewhere. I tried and the lights didn't dim. What I did discover in the process is that the nearside sidelight isn't working. I took the bulb out to replace it but on close inspection it's clearly fine. As an experiment, I swapped it with the offside sidelight bulb. Still the nearside sidelight wasn't working, so the bulb is fine but the sidelight doesn't work. Could this be part of the same electrical issue that's stopping the starter motor from working?
Also, I noticed some corrosion on what I believe is the earth strap where it connects to the positive battery terminal - see pic below. Could this be a part of the problem? NB. Ignore the yellow crap in the pic - that's the foam from the padded battery jacket that's disintegrating.
MB140 said:
Have you taken a jump lead and connected it between a clean metal part of the engine and the negative on the battery and tried to start it.
If you have a bad earth somewhere this would show it up as the engine would start. Have you tried this?
I don't have a jump lead. Is there something else that would be suitable?If you have a bad earth somewhere this would show it up as the engine would start. Have you tried this?
steveo3002 said:
you'd think they would help you out by making them in bright red and marking the post +
no offence but if you don't the difference between +/- id step away before you do some damage to it
I know which is the positive and negative terminal on the battery, I can see the +/- symbols, however, the negative terminal only has the one cable attached to it. The positive one has two cables going to the terminal and a third cable attached to the top of the bracket that holds the main two onto the terminal, hence why I thought that might be the earth strap.no offence but if you don't the difference between +/- id step away before you do some damage to it
paintman said:
Usually there will be a single wire from the -ve to an earth point, usually on the body in the vicinity of the battery.
Yes, there's one wire coming from the -ve. I'm not sure where it goes - I'll have to look - but there is a cable bolted to the suspension strut "dome" in front of the battery, so that could be it.Just a case now of establishing if I have something I can use to connect the -ve to the chassis (as I don't have any jump leads) so I can see if I can start the engine. Once I've done that at least I'll know what to tell whomever I call in to fix it.
Still trying to find someone with jump leads. In the meantime, I looked at the connections again.
Thick black cable from the -ve on the battery is connected to a tab on the "dome" containing the suspension strut. There's another black cable connected to the same dome which disappears under the fuse box and continues under the battery. I can't tell where it goes after that.
Nothing else to report!
Thick black cable from the -ve on the battery is connected to a tab on the "dome" containing the suspension strut. There's another black cable connected to the same dome which disappears under the fuse box and continues under the battery. I can't tell where it goes after that.
Nothing else to report!
phumy said:
Cheapest I could find and are probably rubbish too but come on, you have to borrow some? Go buy a set
https://www.ebay.co.uk/itm/100-AMP-CAR-JUMP-LEADS-...
Happy to buy some - just won't be able to do it until the weekend.https://www.ebay.co.uk/itm/100-AMP-CAR-JUMP-LEADS-...
Not much to report until I've picked up some jump leads on Saturday, though I'll speak to my local garage guy on Friday anyway.
In the meantime, I discovered that you can test for bad grounds by putting the multimeter into continuity testing mode and attaching the black probe to the -ve on the battery, then touching the red probe on the various earth points. I did this and tested the four ground points that I could find, all of which returned 001, which I believe is as it should be. The engine block, however, which I understand can also be treated as a ground, returned all sorts of random numbers. Maybe the earth cable running from the engine to the chassis is the culprit, but I can only see the end that's attached to the engine block and I can't even reach that.
Anyway, we'll see what Friday brings.
In the meantime, I discovered that you can test for bad grounds by putting the multimeter into continuity testing mode and attaching the black probe to the -ve on the battery, then touching the red probe on the various earth points. I did this and tested the four ground points that I could find, all of which returned 001, which I believe is as it should be. The engine block, however, which I understand can also be treated as a ground, returned all sorts of random numbers. Maybe the earth cable running from the engine to the chassis is the culprit, but I can only see the end that's attached to the engine block and I can't even reach that.
Anyway, we'll see what Friday brings.
Just had the guy from the garage out...
Booster pack on battery: Nothing.
Jump lead from -ve to block: Nothing.
Attempt to bump start: Nothing.
He's now arranging to get it towed so he can get it on his ramp.
Odd how a car can be parked working fine and a month later, be completely dead, even though the battery is fine!
Booster pack on battery: Nothing.
Jump lead from -ve to block: Nothing.
Attempt to bump start: Nothing.
He's now arranging to get it towed so he can get it on his ramp.
Odd how a car can be parked working fine and a month later, be completely dead, even though the battery is fine!
Sheepshanks said:
On the upside, at least it has a definite fault. It's a nighmare when these things are intermittant.
Definitely. I was concerned that it would suddenly and inexplicably work again and then I'd be worried that the fault would return when I'm out somewhere. I'd sooner something is broken and is then fixed, even if it means spending some money.Garage called and said they couldn't find a fault anywhere, so maybe the key's not talking to the immobiliser - have I got any more keys? I was already using the spare master as the main master had broken - it was one of those fancy (but relatively fragile) ones with a built in torch and it had disintegrated years ago when I used excessive force on a stiff lock. Funnily enough I'd bobbed into a BMW main dealer last weekend for a quote to get that replaced. Anyway, I went down to the garage at lunchtime with the valet key and bingo - engine started! Perhaps if the car hadn't been sat for a month, thus prompting thoughts of battery failure or a seized starter, I might have thought to try a spare key in the first place!
Facepalm.
Facepalm.
I didn't think I had another key at the time.
The casing on the main master key had broken apart a few years ago when I used too much force on it in a sticking lock. The spare master key - which I'd be using since - was the one that wouldn't start the car. The other key which I have - the valet key - I mistakenly though that one would unlock the car but not start it. Turns out it does start it but won't open the glove compartment or boot.
At least I know what all the keys do now!
The casing on the main master key had broken apart a few years ago when I used too much force on it in a sticking lock. The spare master key - which I'd be using since - was the one that wouldn't start the car. The other key which I have - the valet key - I mistakenly though that one would unlock the car but not start it. Turns out it does start it but won't open the glove compartment or boot.
At least I know what all the keys do now!
Sheepshanks said:
The valet key is for a parking valet to use - you obviously don't frequent the right sort of places. 
I thought by "valet" it meant someone valeting your car, who would need access to the interior to do the inside, but not necessarily need the ability to start the engine. I think the chances of me ever frequenting those kind of places, when my income restricts me to driving a 22+ year old shed held together by little more than duct tape and hope, are vanishingly small!Gassing Station | Home Mechanics | Top of Page | What's New | My Stuff