Hi all. I've watched for a while, but am now excited to start sharing/gaining info here. I have an 88GXL w/stock alarm and the only time it works is on a really hot summer day. I searched but didn't find much info on this system. Why does it only work like 4 hot summer days out of the whole year? I want to try to keep this system intact.

 

Sounds like cold solder joints in the alarm CPU, you would want to pop it open and check.

But first; are you sure you are arming it correctly?

Turn the key off, with the drivers door open lock all the doors with the lock tab at the handle inside the car.

Hold the drivers outside handle up, while closing the drivers door. the system should arm.

On the 88's the system will not arm if you open the truck or passengers door within 2 minutes of arming or they are the last opening closed.

 

I think I'm using it correctly, as it works really well when it works, and it works just like you said. Do you know which connections in the cpu are for the alarm? It makes sense to me that the expansion in high cockpit heat might make the connection. Is there a good cpu diagram available here that show me which is what?

 

On the '88 the alarm CPU is by itself located just under the glove box. It is not integrated with the body CPU as in the series 5 and 6 cars.

There is a 88 shop manual online, it has the electrical connections in it.

It won't have the board schematic though, just the wiring connections to the car. But that is all you will need to troubleshoot it.

This guy on Ebay has brand new ones for sale ocassionally: autopartauctions

And if anyone knows where I can find the actual internal board schematic of the alarm CPU I'd pay money for a copy.