Some Electrical Gremlins after M30 Swap

[talltorontoguy]

Hi guys - I'm new to this board but not new the scene. This seems like a great site with a good bunch of folks.

I just finished an M30 swap into my E30. The E34 donor was an 89 E34, my E30 is an 88 convertible / cabrio. The electric windows don't work with the engine running. I've done a lot of research about the unloader relay and the green/black wire to starter but I still can't track this problem down and so I'm hoping one of you can help.

Here's the information:

1. The electric windows don't work when engine is running but do when engine is off but ignition in run position.

2. Heater fan and mirrors do work when engine is running.

3. There is a green/black wire already attached to the smallest terminal on the starter.

If I'm understanding correctly, the heater fan, mirrors, and windows are all supposed to fail at the same if the issue is the green/black wire to pin 15 on C101 from the starter.

Here's what I've tried:

1. I pulled the unloader relay K5 (furthest left in box, closest to left fender when looking at fuse box). Bridged pins 87 and 30, and the windows worked whether the car was running or not.

2. I then swapped relays, but had same issue. I believe that rules out the relay and any wiring past the fusebox to the windows and leaves the wiring going into the fusebox.

3. Despite there already being a green/black wire to the starter, I cut the brown / black wire on pin 15 on the C101 connector (the E34 engine harness side, it matches up to green/black on the chassis side of C101). I spliced a wire onto it and ran it to the smallest terminal on the starter (where the green and black wire already resides). Still no power windows when engine running.

Does anyone have any thoughts on how I can troubleshoot this item?

I remember reading somewhere about some wiring behind the glovebox that is related. Could that that be the culprit? Maybe something there got dislodged during engine swap?

Any help is greatly appreciated.

Thanks!

Rod

[talltorontoguy]

Anyone?

[Brianmoooore]

Your reference to "fender" rather than"wing" suggests you are not in the UK! Your first post was at 2am, UK time, and your second at 4.28 am. Most of us around here tend to have about 7 hours of kip at night, so you're not likely to get many replies at these times!!!
Windows/roof are fed through K5, and mirrors/heater fan are fed through K7. Both relays share the same control circuit through the starter motor, but have different feeds to the 'live' end of their coils. K5 is fed direct from the green ignition switched live wire, but K7 is fed from the same supply, via fuse 10.
Check each relay has power on pin 86 with the ignition on by connecting a 12 volt bulb between these pins and earth.
If this is OK, connect the black/green at the starter motor to the inner large (13mm nut on an 8mm stud) terminal instead of the small one.

[talltorontoguy]

Yes correct that I'm from Toronto Canada, across the pond.

Also correct on the times of posts, however the two posts were 4 days apart, not on the same day - hence my 2nd request for help.

I'm going to try out your suggestion and will post findings.

Thanks much!

TTG

[talltorontoguy]

Relay k5 does have power at terminal 86 when ignition is in "run" .

I moved the green / black wire to terminal 30 on the starter (the 13mm inner one on starter, closest to block).

No change to situation; windows work when in "run" but not while engine is running.

Thoughts? Could it be something else that has become fooled up on the chassis side?

TTG

[Brianmoooore]

, however the two posts were 4 days apart,

Oops! Didn't notice that!
What happens if you disconnect the black/green from the starter motor, and connect it to earth?

[talltorontoguy]

Will investigate and let you know.

[talltorontoguy]

Problem Solved:

On your advice I started playing with connecting the green/black to ground (earth). No difference. In fact, it didn't make any difference if the green/black wire was connected to the top terminal (8mm nut) on the starter.

It got me thinking so I put a new splice into Pin 15 again at the C101 connector and ran a wire direct from pin 15 to ground. The windows worked whether engine running or not (they also worked if I pressed the button while the engine was cranking - not a good thing). That indicated that the problem was between the top terminal on starter and pin 15 on the C101.

So - I decided to start over, put on new connectors and ran a wire from pin 15 on C101 to the top terminal on the M30 starter (8mm nut) where the green/black wire is resident.

It worked! So... I guess one of my connections wasn't solid to begin with and this was the cause of my problem.

It was the suggestion to put to ground that got me thinking so thanks Brian!

TTG