Speedo, Tacho, Clock and Radio not working

[e30Brah]

Hey guys,

I've got a 318i which I'm fixing up, I've got an issue with the speedo, tacho, clock and radio not working. I bought the car with these issues from the PO, and I believe him saying something along the lines of the radio suddenly not working about 6 months back. The coincidence of these all not working makes me think fuse or SI board - I've taken the cluster out, and need some help!

I really want to narrow down what's causing it; since I can purchase a used working cluster (odo isn't working, should be an easy fix with new gears) but I don't want to if it's a fuse that's gone haywire and the cluster actually works.

I've really got no idea about the wiring, so a detailed diagram with some help as to what to look for would be great!

One more thing, the speedo does work, however it is a little behind as in you'll be driving at 60km/h but the speedo reads 50km/h - I haven't driven it in a while, so it may not be working at all now.

But as mentioned, the clock and antenna do not work, it has an after market radio, and the antenna is up and won't go down obviously.

Thankyou!

Oh and it's probably worth mentioning that this is a different cluster to the one the car originally had, the PO replaced the old dashboard and cluster with the current one.

[Gregs///M]

Replace fuses 10, 12, and 21 with 7.5A fuses.

[e30Brah]

Replace fuses 10, 12, and 21 with 7.5A fuses.

I've had a look inside the fuse box, 10 and 12 are fine; both 7.5A. I had a bit of a play with 21 and it's blown three 7.5A fuses, even with the car off. Had the radio working for about ten seconds until it blew again - so now the issue is finding what is causing the short and the fuse to blow.

I've got the glove box light to work despite #21 being blown which is odd, is it on another fuse?

But the real issue is the fuse blowing the second I put it in contact with 21. I've looked under the gear stick cover for the wires, they're not rubbing so I'm not sure what is it.

Could this be causing the tacho and speedo to not be working?

Also had an issue today with the car dying. I jump started it, it runs, then rumbles, then dies on it's own - happened a few times and I can't get it to keep running :/ - could it be because I was just playing with the fuse box and keeping doors open, etc - so the battery needs a charge?

Thanks

[Gregs///M]

If fuse 21 is blown, tach and speedo will not work. Unfortunately, fuse 21 has a ton of things associated with it.

You'll have to narrow it down. Check under the rear seats, behind the rear seats, the harness near the tail lights inside the trunk, etc. Also check the power antenna and radio. Unplug them both for now.

[e30Brah]

If fuse 21 is blown, tach and speedo will not work. Unfortunately, fuse 21 has a ton of things associated with it.

You'll have to narrow it down. Check under the rear seats, behind the rear seats, the harness near the tail lights inside the trunk, etc. Also check the power antenna and radio. Unplug them both for now.

Alright, quick update.

I had a check around the trunk hinge and the shift cover, as well as the lighter. Removed the whole lighter, there was a couple of screws and metal hair clips around which may have caused it, but fixed that back up. And shifted the trunk wire over, long story short - #21 hasn't blown! I've got the tacho working, interior dome lights working, glovebox light, as well as service lights, etc. Haven't checked if the speedo is working since the car died before I got a chance to test it with the dash in.

Still got the issue with the car dying though. Today it wouldn't even crank, pushed it around to the service station, he charged my battery up and I drove it home. Turned it off, tried the tacho, worked fine, and tried to drive it into the garage, and it died again. Tends to start up fine, idle a bit and eventually die OR dies trying to drive it.

This sound like an alternator or battery issue?

Thanks!

[golde30]

If a jump to the battery allows you to drive for a little bit before dying, sounds like an alternator.

[e30Brah]

If a jump to the battery allows you to drive for a little bit before dying, sounds like an alternator.

Anyway to confirm? Or should I take it off to the mechanic?

I jumped it again before and it seemed to start fine and run fine on idle, I turned it off, ran again, etc. I haven't tried driving it though, so I might try that tomorrow and see what happens. I just want to know if the speedo works! :D

[Todd Black 88]

Get it started and measure the voltage at the battery. Should be above 13v when running.