Temporarily Bypass Starter Relay/Neutral Safety Switch?

[Cinnabar325is]

In two days, I'm going to pick up a '91 325i sport package car. It's been sitting awhile and it is an automatic. It ran well when parked, but we tried to jump it when I went to look at it the first time and it wouldn't crank. The owner said before it was parked, he was having to fiddle with the gear selector to get it to start. Sounds like maybe the neutral safety switch is failing.

I'm driving two hours to get the car. The way it is parked and the layout of the driveway basically means there is no way I'm getting the trailer in to where the car is. I'm basically counting on getting the thing running just so I can drive it onto the trailer.

What is the method for temporarily bypassing the starter relay on an automatic car?

Somewhere I read jumping pins 11 and 14 of the diagnostic plug. Is that correct?

Thanks.

[nando]

Look up the wiring for a 5 speex swap. You can do it all right at the shifter from inside the car. Definitely not at the diagnostic plug.

[Cinnabar325is]

I did find Yoshi's 5 speed swap write-up and his method of bypassing the neutral switch. The thing is, that isn't really temporary because you have to cut the connector off and crimp wires together. I just want something that allows me to get the car on the trailer and then I can fix it for real when I get the car home.

If I look at a pinout of the diagnostic connector it says pin 11 is the starter/start signal and pin 14 is battery positive. In my mind, it makes sense that if I jump the two with the car in the ON position, the starter should crank.

But maybe I'm forgetting something.

[dnguyen1963]

What's wrong with pushing the car out of the driveway and onto the trailer? E30 is not that heavy.

[Cinnabar325is]

If you saw the driveway, you'd know. Besides, have you ever tried pushing a car with rusty rotors up trailer ramps by yourself?

[nando]

I did find Yoshi's 5 speed swap write-up and his method of bypassing the neutral switch. The thing is, that isn't really temporary because you have to cut the connector off and crimp wires together. I just want something that allows me to get the car on the trailer and then I can fix it for real when I get the car home.

If I look at a pinout of the diagnostic connector it says pin 11 is the starter/start signal and pin 14 is battery positive. In my mind, it makes sense that if I jump the two with the car in the ON position, the starter should crank.

But maybe I'm forgetting something.

then use a paperclip or some jumper wires.

or, take it as step 1 to the 5 speed swap every E30 deserves. :p

I didn't think you can start the car that way. Unless the neutral lockout is really dumb and lets the fuel pump & ignition run. Maybe it is..

[dnguyen1963]

If you saw the driveway, you'd know. Besides, have you ever tried pushing a car with rusty rotors up trailer ramps by yourself?

One person is tough. I assumed that the seller can give you a hand. I have done this before. Jack up the wheel and spray PB blaster all over the rotor (you are going to replace everything later anyway). Spin a few times to break up the rust and she should be good to go. Bring some friends...beer or pizza can be good incentive.

[Cinnabar325is]

For future, reference I want to update this. Pins 11 and 14 did indeed get the car to crank when nothing else I tried would.

However, as Nando noted, it still may not have allowed fuel and spark. I pulled a plug and there was no spark, nor was the plug wet after cranking awhile.

The only catch is that much more had been disconnected and removed on the car than I previously thought, so I had quickly cobbled the engine back together to attempt a start. So the reasons for no spark/no fuel may lay elsewhere. Didn't have time to troubleshoot.

Ended up pushing, then using straps and a come-along to get the car on the trailer.