Tried to start the e30 today. (electrical troubleshooting)

[randomtask37]

[UNHCLL]

Fuse #10:

Seat belt warning system
You have these still plugged in?

SI Indicator
All connections are tight and correct on back of cluster?

Tach/fuel eco gauge
Same as Above

Instrument gauges and indicators
Again

Brake warning system
Cluster?

[b]Backup lights[b/b]
Check tranny switch and connections to rear lights

OBC
THESE WIRES!!!! - you removed your OBC correct? The wires that should plug into this, all are capped/crimped/sealed etc? I'd be wary of this part....

Fuel delivery
Check the Pump to make sure its not siezed

Idle Speed
Shouldnt matter since its not starting

Check Control
Plugged in?

Stop lights/cruise control
Check the bulbs, connections in tail lights, and cruise control wires under dash on column... You removed CC correct?

A bad ground can cause a fuse to pop, for example if a hot wire goes directly to a ground, the fuse will act like a light bulb filament.

Keep us posted

[Jordan]

Pops as soon as the key is turned to the first position forward

You have a bad ground somewhere if this is the case.
What is listed for components on Fuse 10?

Also, just to cover all base's you are running the proper amp fuse?

What makes you think a bad ground, rather then something shorting out?

Yes I am running the proper 7.5amp fuse

Fuse #10:

Seat belt warning system
SI Indicator
Tach/fuel eco gauge
Instrument gauges and indicators
Brake warning system
Backup lights
OBC
Fuel delivery
Idle Speed
Check Control
Stop lights/cruise control

[UNHCLL]

Pops as soon as the key is turned to the first position forward

You have a bad ground somewhere if this is the case.
What is listed for components on Fuse 10?

Also, just to cover all base's you are running the proper amp fuse?

[Jordan]

How old is the fuel pump? They are weak units, it could have died while sitting around.

So grab the multimeter and start ohm out the fuel pump loop.

The pump came out of my parts car, it has been dry and in storage for about a year. It did work fine prior to removal. I will test it tomorrow as I need to fix my multimeter (one of the probes fell off.. ghetto)

[Jordan]

Does it pop when you crank, or when you turn the key to the "on" position?

You have the pump wired up correctly, yes?
All your chassis grounds are good?

Pops as soon as the key is turned to the first position forward

Yes, the pump is wired correctly, the 2 terminals are of different sizes, so it is impossible to mess that up.

I would assume all chasis grounds are tip-top. All of them were hit with a diegrinder to bring to metal (where paint was sprayed) then bolted down.

[Jordan]

Fuse 10 generally blows when the wire for the backup lights shorts out, at least thats what it was doing in my car. I'd see if for some reason or another your wire is frayed and if so replace it (duh)

I made a brand new reverse light harness from scratch for my car (much improved over the stock design, thick plastic shielding over the wires etc)

This is not the problem, that I can say with certainty

[M-technik-3]

How old is the fuel pump? They are weak units, it could have died while sitting around.

So grab the multimeter and start ohm out the fuel pump loop.

[UNHCLL]

Does it pop when you crank, or when you turn the key to the "on" position?

You have the pump wired up correctly, yes?
All your chassis grounds are good?

[boom-monkey]

Fuse 10 generally blows when the wire for the backup lights shorts out, at least thats what it was doing in my car. I'd see if for some reason or another your wire is frayed and if so replace it (duh)

[Jordan]

Checked and double checked everything, finished topping off with fluids, connected the battery and gave it a crank.

It cranked for maybe 2 seconds before the battery died... dammit, forgot to charge it up

Backed the M3 up to me, and connected jumper cables

Cranked it again. No start. And again.. no start.. well it cranks like a champ, thats about it.

After a quick check on the fuse box I noted fuse #10 had blown, I replaced it, and went for another crank. This time I saw it blow

Before checking what it was I took the fuel line off the fuel rail, bone dry. Had my stepfather try to start it while I listened to the fuel pump... not pumping.

ARG!! well I looked up what fuse #10 did in the Bentley, and it does say "fuel delivery" amoung many other items. So I suppose fuse #10 is my arch enemy now.

I have the battery on the charger, gonna leave it on over night. I shall try to track down the problem in the morning, until then does anyone have any ideas?