QuestionThanks Roland for any and all assistance you may offer.
My mother-in-law has given me a 1991 Chrysler Fifth Ave. because it quit running. It has set for about a year. She tells me she was told that the anti theft system will not allow the car to run. I'm guessing the battery is unusable. I have no other ideas where to start. What do you think?
Feel free to ask questions if you need to.
I'd like to see if I can get this thing running so I can give it to my son.
Thanks again.
AnswerHi Mark,
Yes the theft alarm system if armed and then violated will put the engine controller in a mode that prevents the engine from running more that a second or two. And you have to disarm the system by locking and then unlocking either front door with the key. Similarly, when you disconnect the battery the same shut down will occur so you have to use the key in the door lock approach to defeat the shut down. However, if there is a problem with the switch sensor or its wiring in the door(s) then it won't defeat the shut down. There is an on-board way of testing all the sensors and switches of this system, the failure of any one of which is then a reason to look into that component and repair its function. I typed up the self-diagnostics earlier for another questioner and here it is:
"Let me type in the System self-diagnostic test for possible help to you and the shop:
A diagnostic mode is available in the system to verify operation of all monitored switches or circuits. To enter diagnostics, cycle the ignition key to the accessory position 3 times, leaving the key in this position.
Upon entering diagnositics, the park and tail lamps will begin flashing to verify their operation. In addition, the horn will sound twice to indicate that the trunk key cylinder is in its proper position. Returning the ignition to the OFF position will stop the lamps from flashing while keeping the system in diagnostics.
While in diagnostics mode, a horn pulse should occur at each of the following events indicating proper operation:
(1) Beginning with all doors closed, open then close each door. The horn will sound when the door ajar switch closes, and then again when the switch opens. There must be a 1 second delay between closing and opening the switch.
(2) Open, then close the hood. The horn will sound when the hood is opened, and again when it is closed.
(3) Activate the power door locks in both the lock and unlock directions. The horn will sound after each activation.
(4) Rotate the key in each of the door lock cylinders to the unlock position. The horn will sound as the switch closes, and again when it opens. There must be a 1 second delay bwtween changing switch states, or the horn will not sound.
(5) Cycle the key to the ignition RUN position. A single horn pulse will indicate proper operation of the ignition input. This will also take the module out of diagnostics mode. For any of these tests, if the switch does not remain open or closed for at least 1 second, the horn will only sound once.
The lack of a horn pulse, during any operation, indicates a switch failure, the lack of that input in the Vehicle Theft Security system module, or a failure internal to the module. Check for continuity at the switch, if this is good, check for an open or shorted wire between the switch and the alarm module. Also, check if the SBEC (engine control computer) has been replaced recently. Vehicle Theft Security System will not function until 20 engine cranks."
There is also a fault tree drawing of the step-by step in the manual which I could copy and snail mail to you as I don't have a scanner, so if you want it let me know via a follow up question giving me a postal mailing address. So I would try to recharge the battery or get a new battery but then you do have to deal with the issue of defeating the theft system by analyzing what part of it isn't working the way it is supposed to and thus preventing the disarming.
Roland
