525e No Crank

E28 technical advice asked and given! Troubleshooting, modifications and more.
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tomman7531
Posts: 4
Joined: Mar 26, 2023 6:13 AM
Location: Southampton

525e No Crank

Post by tomman7531 »

Hey All,

New here, so hello to all :)

Pulling my hair out with my 1985 RHD 525e, we get no crank when trying at the key, the starter has been replaced, and the car does start when jumping the pins on the diagnostics port.

I have 3 relays under the steering wheel, they have been tested elsewhere and tried moving them around to see if that helped, it did not. Relief relay in the engine bay is clicking when pins are jumped, I'm at a loss here.

When you put the key into the crank position the red (!) symbol comes on in the cluster and stays on for however long you hold the key in cranking position, not sure if that's normal or helpful?

If anyone can help it would be very apricated, fairly new to the car so learning as I go.

Thanks,

Tom
Mike W.
Posts: 26872
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: 525e No Crank

Post by Mike W. »

Welcome to the group!

The red ! doesn't sound familiar, I don't think it came one US spec cars. Do you have a link to a wiring diagram? I've got all the US ones, but yours is obviously different.

Anyway, is it an A/T car? If it is it could be the neutral safety switch. Try neutral and wiggling the shift lever. It could even just be a bad ignition switch, but that red ! suggests a different problem.
Aldo525
Posts: 276
Joined: Mar 24, 2021 3:04 PM
Location: CHILE

Re: 525e No Crank

Post by Aldo525 »

The cluster symbol (!) is euro red light to "Brake Fluid" in US specs, same position at cluster.
tomman7531
Posts: 4
Joined: Mar 26, 2023 6:13 AM
Location: Southampton

Re: 525e No Crank

Post by tomman7531 »

See trouble is I don't see why the brake symbol would stop the car starting, brake pedal doesnt need to be pressed, fluid is full, and when the engine is running there are no lights on dash.

As for natural switch, it does read the correct gear on the dash but I assume that not relayed by the neutral safety switch.

Could someone let me know where it is and if there's a way to test it?
Aldo525
Posts: 276
Joined: Mar 24, 2021 3:04 PM
Location: CHILE

Re: 525e No Crank

Post by Aldo525 »

tomman7531 wrote: Mar 28, 2023 11:00 AM See trouble is I don't see why the brake symbol would stop the car starting, brake pedal doesnt need to be pressed, fluid is full, and when the engine is running there are no lights on dash.

As for natural switch, it does read the correct gear on the dash but I assume that not relayed by the neutral safety switch.

Could someone let me know where it is and if there's a way to test it?
So your car is Auto trans like mine (euro 525i). If the selector is showing the right gear I believe the switch is ok, but check the wire that goes to the starter....a simply black wire connected same area where all the battery cables reach the starter. Maybe is unplugged (due to the starter replacement) or rusted. I had that problem and this loose wire was the culprit.
Mike W.
Posts: 26872
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: 525e No Crank

Post by Mike W. »

I've got to think it would be a separate contact and wire for the neutral safety switch and the indicator lights. The ETM shows the contacts as bridged between park and neutral which wouldn't work for the indicator lights. The neutral safety and lights are incorporated into one switch assembly right at the handle. I've had success before spraying contact or electrical cleaner down into the slot where the lever moved thru the switch, then moving the lever back and forth a number of times which cleans the switch contacts.

There is also the start relay under the kick panel somewhere which probably has black and black/yellow largish wires attached to it.

And it's even possible it's the ignition switch itself.
tomman7531
Posts: 4
Joined: Mar 26, 2023 6:13 AM
Location: Southampton

Re: 525e No Crank

Post by tomman7531 »

So I patched the two wires as shown online for the natural safety switch and no difference, so I guess that leaves the barrel or this black wire on the starter
tomman7531
Posts: 4
Joined: Mar 26, 2023 6:13 AM
Location: Southampton

Re: 525e No Crank

Post by tomman7531 »

Sorry for the late follow up, it was the ignition switch!

For anyone with similar no crank issues at the key, this is how you test the ignition switch:

Remove the drivers side lower dashboard cover so you can see all the dash wiring and steering stuff

Remove the 3 phillips head screws that hold on the black plastic covering the lower steering column (Two long screws at the steering wheel end, 1 small one behind the steering wheel reach adjustment

With that removed, you should be able to see the ignition barrel, on pre Sep 1985 cars (I think its clips thereafter) there is a very very small flat head screw thing, mine has yellow markings on it, that when removed allows you to remove the ignition switch from the back of the barrel (cant be a bit fiddley but will come out.

Then inspect the switch, try to turn the switch with a flat object or the key itself, if it starts then great, new ignition switch, at the time of writing, about £80 from BMW (has to come from Germany so takes about a week)
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