Will not start back up and the "Theft" light on the dash board flashes and makes a clicking noise?

CAVEMANJB

MEMBER
1999 FORD TAURUS
107,000 MILES

My wife drives a 1999 Ford Taurus. After driving the car will not start back up, and the "Theft" light on the dash board flashes and makes a clicking noise. I removed the positive connector from the terminal, cleaned the minimal corrosion that was there, and when I reconnected it the car started.

This doesn't always work though. Now I have to disconnect and reconnect the positive cable several times before it will start. Everytime I reconnect it power is restored in the vehicle (radio, wipers etc.) Then when I turn the key it loses power immediately and the "Theft" light flashes.

A couple things to note: the car has had an autostart system installed, and they bypassed the security system to do so, though it worked fine for some time since that. Also, I changed a headlight recently. Not sure if that has anything to do with it but thought I would mention.

Any thoughts on what the problem could be?

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

It sounds like there could be a short in the factory anti theft system.
It is possible that the aftermarket start system is crating the fault within the factory anti theft.
Best course of action would be to remove the after market system first then figure out what happened to the factory system. This way it will be a relatively simplified process.
After that you can install the aftermarket starting system if you chose.
You will have to trace the wires for the factory anti theft. To perform this properly you will need a multimeter, which will allow you to check for any short or excessive resistance due to broken wire insulation between two wires.

Here is a guide of how to check wiring on a vehicle:

https://www.2carpros.com/articles/how-to-check-wiring

I have attached the wiring diagrams for your reference.

Please let me know of any questions.

Thank you.

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