compustar problems in ’91 bmw

1991 bmw 325ix 5spd
Compustar p2w9000-as

Installed alarm/keyless entry/remote start. Alarm works well, keyless will not.

I accessed the central locking unit and can make doors lock/unlock by grounding the appropriate terminal. However, when I connect the lock/unlock wires from the cm4000 (brain) it doesn't lock/unlock with arm/disarm.

I wouldn't think I need relays since 2 are built into the central locking unit, but I'm not sure.

The low voltage outputs of the Compustar doesn't have enough power to trigger the central locking systems of the BMW. Use this link for a negative to negative relay trigger

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA

First off, thank you. Second, do I use a relay for both the lock and unlock wires. Third, if so, are the two relays connected at all?

Okay, I'm begging for help now. I'm very good at wiring but unexperienced in car alarms.

I've tried to add relays to boost the output to the door locks, but no success. Here's additional info to ANYONE who has ideas. PLEEEZ!

The locks work by grounding them. When the doors are unlocked, the lock wire at the central lock unit reads ~9V and unlock wire is 0. When the doors are locked, the unlock wire reads ~9V and lock wire is 0.

The lock & unlock output on the compustar CM4000 read about 20 mV. When triggered by the remote they increase to ~4V. I don't see any difference in the output voltage between changing the jumpers between negative or positive output.

What the heck do I need to do?

I just tried the diagram to convert positive to negative output (although I had already tried that by deduction). Nothing! I just don't get this. The locks all lock and unlock if I ground the appropriate wire. The relays are fine (tested them). I AM LOST!!!

Assuming this is an E30, there should be no "issues" at all with the locks, I disagree with Jeff, that model used very low current switching on the lock/unlock wires.  If its an E36  make sure  your door contacts for dome lights are working properly, and these were pos going. Try to emulate whats happening with the doors shut. Personally I think the problem is with the alarm, also if E36, if the alarm locks are not relay driven, i.e. 2 not 6 wire lock outputs, then diode them as well.

It's an e30. I just cannot figure this out.

Your in Seattle? Why don't you call firstechnd ask for tech support.

Dont forget your outputs on the compustar brain only generates a 250Ma ground.

206-957-3780  Ask for either

Wade, Mikey, Ray, Nic, or Bert

All four can help you.

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"dont ground out!"

Thanks dswift. Howie II was right. The alarm was defective. I sent it in for a replacement.