Expert: Rob Painter - 2/10/2009

Question
QUESTION: hi i have a 95 deville that will power up when the key is turned over but it wont kick over could this be a negative ground short or the starter thanks for your responses

ANSWER: Hi Anthony,

I really don't understand your question. Do you mean the lights come on in the RUN position, but the engine won't crank? If so, the first thing I would consider is the factory anti-theft (anti-owner) system.

Riddled with problems and being an antique, that little resistor controlled junk with the "chip" in the key is notorious for no crank problems.

I am not saying that absolutely is your problem, but 95% of the time it is.

Just for fun, try tiltling the steering wheel up and down a bunch of times and try to start.

If that doesn't work, try shifting through the gears.

The only reason I say this is that if the engine starts, you have broken VATS wires in the steering column and it is just best to bypass all together and at the same time install a HIDDEN starter kill switch.

If you find that to be the problem, the VATS is easy to bypass.

Rob

---------- FOLLOW-UP ----------

QUESTION: ok like ill stick the key in the ignition and turn it over all of the dash lights come on but it wont krank over so i was wondering could it be a ground or possibly the starter?

Answer
Hi,


You description of the symptom, of where the engine will not crank is consistent with the GM VATS Anti-theft system.
This has nothing to do with a short as you put it, in the starter circuit, and the common problem I am referring to is located in the steering column.

In order for the engine to crank, the vehicle's computer needs to see the use of the correct resistance key.
The ignition lock for this vehicle has a 2-wire harness in which one wire feeds up the column with a contact on one side of the lock keyway. There is another contact inside the front of the lock cylinder that runs down the steering column. When you insert the key into the lock, the resistor chip on the key blade (Commonly incorrectly referred to as a computer chip, which it isn't) completes the circuit.

The two VATS wires are very thin and commonly break inside the plastic casing. Once broken, the circuit is open and the vehicle's computer cannot read the resistance from the key and the engine won't crank.

The reason I told you to tilt the steering column and shift the gears, is that it is possible that the broken wire will reconnect allowing the engine to start.

The most common complaint with these VATS equipped vehicles at the dealer was "engine starts at times."
If you replace the over priced ignition lock, the problem will just show up again. It is better just to bypass this junk.

The only problem with the bypass and if the car is stolen (takes as little as 30 seconds to defeat a steering column where the engine can start without a key), the insurance company will deny your theft claim, because of the ignorance and arrogance of the insurance company, because according to them, a vehicle so-equipped is "Unstealable."

This is the reason that you would now have to install a hidden starter disable switch for security.

Many believe thieves will not steal old cars. This is not true. These cars are great for joy rides and to commit other crimes, and since they are older, they just blend in.

Unless there is obvious damage like a broken window on a cold day, or the trunk lock being ripped out, cops rarely pull these cars over.

Try playing with different tilt positions and shifting the transmission and trying to start the vehicle.

If it starts, you know that is the problem. I have seen people far too many times replacing starters and everything else, but finding the actual problem--the VATS.


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Rob Painter http://www.autotheftexpert.com


Good luck,

Rob