84 security wont let engine start
 

Hi,
I just recently took out and rebuilt my engine for my 84 C4. It is back in and hooked up and ready to go, or so I thought. I get in the car and put the key in. "Security" flashes on the DIC. I turn the key to run and the "Security" light goes off. When I turn the key to start the engine, the "Security" light comes on and the engine will not start. I did some searching on here and saw people talking about the door locks controlling the security system. So I put the key in, but did not turn it at all. If the doors are un-locked, the "Security" will flash, if the doors are locked, the "Security" will be light solid. I also saw some people saying that the stock radio could be part of the security system, but I don't believe that because when I bought the car, it already had an aftermarket radio and it ran just fine. I am at a total loss. I hope there is a simple solution, but if not I am willing to bypass the security system as a last resort, but I don't quite know how to do that. Any information would be gratefully appreciated.

Adam

The locks do contribute to the system. Mine in my 84 have to be turned in one direction to trurn off the alarm and then turned the other way to unlock the door. I would try to get them moving.

Unlock door with key to disarm.

Does the engine crank over? The theft deterrent system will disable the starter.


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The door locks work fine. I tried that. Locked it un locked it, by key and by power locks, No change.

Thanks for the diagrams. That should be helpfull if I have to bypass the security system. To your question, no the engine does not crank.

There is an extra switch up in the door lock for theft deterrent. If the actual key locks work does not matter. Unlocking with power locks will not disarm.

Try with the key on both left and right doors.

If you open door, lock with power locks, the security should change from flashing to on. Close door and it is armed.

If you don't have one yet, get the factory service manual.
you can find them all day long on ebay.
also pick up the electrical supplement manual.

​​​​​​​It goes into much better detail, and covers locations better.
​​​

check to make sure that green wire with the white stripe running to the theft deterrent starter interrupt relay has power to it on pins c and d when the key is in the start position. If it does not, you have a different problem, like a neutral safety switch. my manual seems to show the relay on the passenger footwell, but I have not gone looking for it yet.