Main relay issues

[equate975]

Im having issues with my main relay. I checked the bentley and I am supposed to get a constant voltage between the red wires pins 30 and 86 all the time, I am not. Where do these wires end up going so I can make sure they are connected properly?

Also, what relay model is the main relay supposed to have? I have a green one I have 6136-8373700 in there which does not seem right.

[DEV0 E30]

The 3 relays? Shouldn't matter what color.

2 are 4 prong, 1 is a 5 prong however.

[Rev Engineer]

According to the Bently, the red wires are powered all of the time. They go to the B+ terminal which I believe is the primary battery connection under the hood.

[equate975]

Yeah, I was doing it wrong. I think I have the wrong relays in right now, but I cant confirm the models that should be in the main, o2, and fuel pump. Anyone know the P/N for them?

[Rev Engineer]

I'm pretty sure the fuel and o2 relays are interchangeable, unless one has a higher contact rating - they are both electrically the same. The main relay has 5 prongs. I'd be interested to know too, if the fuel and o2 relays are different. Have you checked realoem?

[equate975]

Everyone says that, all ym relays are 5 prong and the main relay and o2 are the same, fuel pump has a different one. If I swap the fuel pump and the main relay like I think it should be, the car wont start,

[Rev Engineer]

Check the Bently again. The main relay is 5-prong and the fuel and o2 are interchangeable 4-prong relays. You can also look down into the socket to find the one that is 5-prong.

[Rocla]

Tried out 3 different relays for main(white), didn't work.

Seems it has a diode inside and can't be replace by "normal" realy.

[aeryk7]

Low Voltage to the DME/Main Relay ...So this is your code right!

Supposedly this has to do with the alternator. I didnt have a snorkel on my alternator and the light came on , i went online and people said this was the alternator. I put a snorkel on my alternator and the code went out , then i made a CAI w/ heatshield which kind of deleted my snorkel then the light came back on. Still have the code and the car still is very strong.

[smokenbaby]

Low Voltage to the DME/Main Relay ...So this is your code right!

Supposedly this has to do with the alternator. I didnt have a snorkel on my alternator and the light came on , i went online and people said this was the alternator. I put a snorkel on my alternator and the code went out , then i made a CAI w/ heatshield which kind of deleted my snorkel then the light came back on. Still have the code and the car still is very strong.

The 5 pin relay is your Injector relay. The 5th pin is the switch pin to turn the Pump back on while cranking. What I found when I did my E30 2.5 conversion was that pin 86 on the pump relay had 12v backfeed when it should be ground. All I did was removed the standard wire going into the relay block for pin 86 and ran a new ground wire. Car started up and has been running sweet. I also reconfigured the standard wiring in the block to allow me to use off the shelf relays from any Auto Parts store. This means instead of using a NZ $60 BMW 30 amp relay I am using a NZ $12 Narva 30 amp relay with a 30 amp Inbuilt fuse. As for the O2 relay, My car doesn't run an O2 sensor so can't help there.

[equate975]

I have power to the main relay.

ALL MY RELAYS have 5 pins, but the o2 and fuel pump plugs have 4 wires going to them, the center pin is not used.

The o2 and main relay are the same, the fuel pump relay is not. If I swap the fuel pump relay and the main relay the car wont start.

[equate975]

Check the Bently again. The main relay is 5-prong and the fuel and o2 are interchangeable 4-prong relays. You can also look down into the socket to find the one that is 5-prong.

I know that, but the bentley dosnt have the part number for the relay that should be in there.

[equate975]

The 5 pin relay is your Injector relay. The 5th pin is the switch pin to turn the Pump back on while cranking. What I found when I did my E30 2.5 conversion was that pin 86 on the pump relay had 12v backfeed when it should be ground. All I did was removed the standard wire going into the relay block for pin 86 and ran a new ground wire. Car started up and has been running sweet. I also reconfigured the standard wiring in the block to allow me to use off the shelf relays from any Auto Parts store. This means instead of using a NZ $60 BMW 30 amp relay I am using a NZ $12 Narva 30 amp relay with a 30 amp Inbuilt fuse. As for the O2 relay, My car doesn't run an O2 sensor so can't help there.

86 should have 12v not ground. Thats what the bentley shows.

[equate975]

http://www.realoem.com/bmw/showparts...61&fg=25&hl=75

#1 is what I have for a fuel pump relay.

#17 is my main relay and o2