e30 not starting

I'm pretty stuck on this one. About a month ago I started having an issue where my e30 wouldn't start. After trying several times to start it, it would eventually fire up and I'd ignore the issue. Well, now it's just dead. The battery was showing good power and I showed power to the starter so I changed the starter. Nothing. Changed the ignition switch, still nothing. Everything lights up like it should with the key in the on position but when I turn it to start it's just nothing. No trying to crank, no clicks. Any thoughts?

ETA: I bench tested the old starter and it seemed to be working fine.

Ignition switch failed

In reply to Sine_Qua_Non:

Sounds like he already tried that.

DanielCut wrote: Well, now it's just dead. The battery was showing good power and I showed power to the starter so I changed the starter. Nothing. Changed the ignition switch, still nothing. Everything lights up like it should with the key in the on position but when I turn it to start it's just nothing. No trying to crank, no clicks. Any thoughts?

I would try testing for power on both sides of the starter relay and maybe give replacing the relay a shot.

Is there a way to test that? I did change the ignition switch but there's certainly a possibility that the one I put in was bad too.

DanielCut wrote: Is there a way to test that? I did change the ignition switch but there's certainly a possibility that the one I put in was bad too.

Was it new or used?

IIn reply to Sine_Qua_Non: Used

Replace the battery cable or or jumper fro the bulkhead lug. Mine did this when I bought it and it turned out the cable had a shirt. It was shall enough that it showed the full 13v when I tested for power but when I turned the key ..... Nothing.

In reply to itsarebuild: Interesting. I'll have to check that out, that's exactly the kind of ideas I was looking for.

Checked the relay (I think it was the right one) and it appears to be good. I guess next is to check the battery cable. Am I correct in assuming it's probably more likely a connector on the cable and not the cable itself that's bad?

I never actually figured out where mine was broken. Just that it was. For the short term I moved the battery up to the engine bay on the passenger side and ran a really short cable to the junction block on the firewall right there. Long term I bought a battery relocation kit from summit and dropped the battery into the tire well. Long cables are cheap these days so it wasn't worth the effort to find the flaw in the cable.

Gotcha. That's sort of what I was wondering. Wasn't looking forward to pulling carpet up to replace that long wire.

The last time this happened to me with the 2.5L motor from the E30, I fixed it by replacing the distributor cap. Hairline crack that is invisible to me, or some other defect, who knows? But that fixed it.

First I took jumper cables to the terminal box in the front of the car to see if I could start it that way, with a known good battery. The starter turns over, I know I don't have a problem with the power feed. If it hadn't turned over, I would have replaced the starter feed cable before I went after the trunk feed cable.

Something about your sitch makes me think something is shunting your power to ground.

Is it a manual trans with a safety switch on the clutch pedal?

Finally got a helper over and was able to read voltage with someone turning the key. No appreciable drop from the battery, junction on the firewall or at the starter.

The M42 uses coil packs so no distributor but grounding out somewhere seems plausible. Next free day I'm probably going to go back in and pull the new starter just to make sure it wasn't bad out of the box.

This is a manual car but I don't think e30s have clutch safety switches.

They do not. You either have a bad ground, relay, ignition switch or starter. Was the starter used too? Old used German electrical parts are always a gamble...start by checking for 12v at the starter solenoid wire when the key is turned to the start position. If it isn't there, check the relays that power the solenoid wire. If it still isn't there, your ignition switch is likely the culprit.

It was a new starter. I'm getting 12v at the starter. But that's why I changed the starter in the first place and the old one bench tested fine.

I'm assuming you're getting 12v at the main starter wire that runs to the battery. My question is, are you getting 12v from the thin solenoid wire when you turn the key?

This pic is of a VW starter circuit but it's roughly analogous to yours. 12v at the starter from the battery (big wire) won't do anything if the starter isn't also getting the switched 12v signal (little wire) to do its thing. You need to follow the solenoid wire back to the relay and ignition switch until you are getting 12v on that wire with someone turning the key. Then you will know exactly where your problem is.

Found a ground that had come loose. It cranks now. Cool thing though, it just cranks but won't start.

Jk, we're all good now. Thanks everybody for all of your input!