Immobilizer fries when the key is used to unlock doors
 

Car had and aftermarket alarm on it, wife hit the unlock button nothing happened. So she hit it again same thing. Took the key unlocked the door, then the Volvo alram (which we had never heard) started going off. She immediatly put the key into the ignition to reset the system and it did nothing, alarm still going off and car would not start. When I returned home I figured the aftermarket alarm had failed so I had it removed by the same shop that had installed it. That did not fix it, but after much effort found the immobilizer box ( alarm box ). It was fried, you can smell it when you open the case. Went to a few salvage yards found one put it in. Car fired right up as if nothing had ever happened. Drove it to church and locked the doors (duh) thinking nothing of it. Came out afterwards turned the key and whamooo... Alarm goes crazy and it again fries the box. Found another box it is in the car and I am driving it now, I just will not lock it until I believe it is fixed. The only thing that I have been able to relate this problem to but not solve is the fuel door release stopped working a few days prior to the first time this happened. The door release test good with 12v to it, and I replaced the switch just in case. Please tell me some one out here has a clue about this. ANY AND ALL HELP IS APPRECIATED. Not really a good plan to leave a car unlocked in Houston.:confused:

Has to be something that messed up due to aftermarket alarm being installed.
They must still have something messed up.

That is what I thought as well. Of course that is the reason I had it removed it by the same shop. That alarm had been on the car for 14 months with no problems until that day.
Is there procedure for test the fuel release door componets. At least if it where working I could eliminate it as a possible cause. Appreciate it tech, you share a lot of knowledge on this forum. Thanks RT

What year is the car?

Sorry about that, all that info and no year.
1998 V70 GLT

Ok the 98 cars are well known for the fuel door release to stop working.
If you pull the switch do you have power at the motor in the back?

Used a test light and found we did not have power at the motor. I bought a new fuel and trunk release switch and installed it, same result, no power, so it must be in front of the switch. Fuses are all good, any idea on what to do next?


RT

Check wiring in the door jam plug. You will see a little torxes screw. Loosen it and turn the outer ring and then seperate the harness make sure one of the pins did not back out.

Thanks I will take a look when I get home, it will be saturday.