Ranger starting problem

[XTechRep]

Sister-in-law has a '94 Ranger with just under 100K miles. It will turn over fine but sometimes not start. It matters not if hot or cold or morning or evening. She has a factory anti-theft device. If she wiggles the connector or wiring harness connected to it, the truck will start. Maybe a coincidence? Headed up this next weekend to check it out, but I have no experience with anti-theft devices. I will do the normal cap, rotor, plugs, etc checks, but was wondering if anyone has had a problem with their anti-theft system. Is there a safe way to disable or remove it?

thanx

[RobbieD]

Howdy, and welcome. A '94 model sounds a little early for the factory PATS with a chip in the key. Check to see if this truck has an "antitheft" or "security" light as part of the instrument cluster display. I'm thinking that the truck might have an aftermarket, but dealer-installed system, which often are sold as "factory" systems.

The part about "wiggling the connector or wiring harness connected to it" is also throwing me; can you describe better what it looks like? Also, how is this system disarmed- by just sticking the key in the switch, or is a seperate fob of some kind used?

Sorry for all the questions, and it's understandable that you may need to get the truck in front of you before you know any more.

[XTechRep]

The truck has a connector under the steering column. You have to plug in what looks like a connector with a jumper in before key starting. I believe it is factory. I am waiting an e-mail with more visuals from her.

thanx

[RobbieD]

Thanks for the added info. I'm almost certain that it's aftermarket, and the description so far indicates a shaky wiring connection. Whatever this thing is, there's a good chance that it can be fixed or removed. Let us know when you have more, or the truck in front of you. Good luck!

[Zaibasis]

Last Sunday I ripped out my Ford anti-theft system in my 93 ranger. It was Ford branded but a dealer-installed device (not the factory device that controls doors, etc). It got so bad that every time I wanted to start the engine, I had to hit the Deactivate button on the key fob and then turn the key (whether or not the sytem had been armed). It was just weird. This was all fine and fun to have a secret-agent-style ignition system - except for one fact - the key fob fails intermittently for no reason whatsoever (yeah I put in a new battery and cleaned the contacts). Nothing like having a faulty electronic device decide whether or not your ignition is going to work or not.

Anyhow, I found the unit under the dash and located the wires that had been cut and crimped from the dealership behind the drivers kick panel and in the steering column. I also found a deactivation switch by the hood release and wires leading to the siren going through the firewall.

Long story short - I put all of the original wires back together and yanked out the alarm and it starts like a champ every time.

[RobbieD]

Uh oh- you might have voided your warranty!

Just kidding; really sounds like you did a good job determining the problem, and fixing it yourself.

[73john]

What is PATS and how is it wired and how does it work? Sounds like the old chip in the key device. How can you tell if your truck has PATS? My Dad's truck is an 04 with plain key. Thanks in advance!

[73john]

Sorry about the last reply, should have been a thread.

[RobbieD]

Don't sweat it; not a bad followup question to an old thread.

PATS stands for Passive AntiTheft System. It's kind of like the old GM "chip-in-the-key", except that it's a wireless transponder in the key head instead of a fixed-value resistor being read through contacts. Basically, when the key starts the engine, the truck polls the transponder, and if the correct code is received back the PATS controller allows the engine to stay running.

Hope that sheds some light on it.