e30 325is crank no start

[regalE30]

Hey guys,

I've been through every crank no start guide and forum I can think of. I have tried everything that I found online and I believe I have narrowed it down to the wiring that goes to the fuel pump from the relay. I'm getting power basically everywhere else except for the fuel pump connector. When put to a power source the pump runs. What I am wondering is how does one go about doing this? I know absolutely nothing about electrical stuff, but I really need to get this car running as its now the only one I have. (I had a e34 540i too but my headgasket went). What kind of wire and connectors do I use? Should I even rewire this, am I barking up the wrong tree? I've swapped crank sensors, ECUs, batteries, jump started it, new fuses, new relays, checked the fusible link, swapped fuel pumps, etc. I don't know where else to turn except to rewire the fuel pump to the relay. I have an extra wiring harness but I could not find the same fuel pump plug on it, I'm guessing theyre on different harnesses? Anyways, sorry for rambling...thanks for any help its much appreciated.

[It's Soda Not Pop]

Do you have a 13 button OBC?

[regalE30]

Yes I do have the 13 button OBC.

[It's Soda Not Pop]

https://www.r3vlimited.com/board/forum/e30-technical-forums/general-technical/49808-obc-immobilizer-bypass

I believe the OBC is your culprit

[regalE30]

That's interesting, I did see a couple threads on it but didn't think much of it because I haven't touched anything to do with it. So should I go ahead and bypass it like the guy says in that thread? My car has a ton of aftermarket wiring for speaker, gauges etc that I didn't do and its been a total mess for me. I'm open to anything to get this thing running

[It's Soda Not Pop]

Unless you can reset the function of the security bit. Then I would bypass it. Again as long as you don't care that it works again in that way. It will still give the time and temp and MPH

[regalE30]

Yeah I couldn't care less about the alarm function or whatever it is. I never set an code though and I'm not sure if the previous owner did. But I just got under there and was looking at the wiring in the drivers footwell and its a total goddamn mess. Looks like a birds nest of wiring and I cannot tell what is what. There are a TON of wires in there and I have no idea what I'm looking at. The OBC also will not display the CODE screen, and when I hold CODE down and the small button to reset, nothing happens.

[82eye]

isn't an alarm supposed to chime after 3 failed start attempts when the obc needs a code ?
i have a 13 button and the PO did not give me a code, nor did he know about one. i'm likely facing this at some point.

[reelizmpro]

Yes. The code is whichever 4 digits you enter before you turn the key off. Apparently, the obc relay can have an internal fault, so that's why people say to bypass it just incase when troubleshooting a no start condition.

[It's Soda Not Pop]

Did you have any luck in figuring out that bird nest of wiring? I know a lot people have no start issues due to the OBC.

[regalE30]

I figured out where the two wires are I just don't have the tools to do it currently