The original owner of my '95 2500 had a car alarm installed when he bought the truck. I bought the truck in 2001, but stopped using the alarm 15 years ago. A month ago the alarm went off in the Walmart parking lot when I opened the door after I did some grocery shopping. I had not armed the system in 15 years! The alarm disabled the starter and I had to get a tow home. I rummaged around until I found the old clicker, put a new battery in the thing, and disarmed the security system. Truck started right up. Then a few days ago it wouldn't start again--turning the key all the way on did nothing. The first thing I tried was to hot-wire the starter, but that didn't work. So I decided to un-install the car alarm. It was a JOB. It took me hours to find the alarm box. Eventually I figured out it was right under the alarm horn. It took more hours to find the alarm relay. I pulled the knee bolster and began clipping zip ties until I was able to locate the relay. The way my alarm worked was like this: The alarm installer cut the wire (blue with yellow tracer in my truck) that sent 12 volts from the ignition switch to the starter relay in the fuse/relay box under the hood. The relay would then be activated, and send 12 volts to the starter solenoid, and the engine would turn over and start. So in total it probably took me 9 hours total, over 2 days, to find the alarm box and also find the proper relay. But the engine still wouldn't start. It dawned on me that I probably had 2 distinct problems. I pulled the Denso starter, tested it and it was bad. Took that bad boy to my rebuilder this morning, along with a set of LarryB plunger/contacts, got it back a few hours later, spent another 40 minutes getting the starter back on the engine and.... IT WORKS!! Yippee.

 

I not a expert on them . I like to watch the utube videos that show how to diagnose automotive problems. Paul Danner for one. I seen several times a alarm system way the problem. Including systems added to cars by a dealer in case the owner misses a payment . A lot of times the new owner was not aware of the alarm installation..

 

That's how I found out I needed to find the right relay--I watched a YT video. Once I found the relay, and saw the blue wire with the yellow stripe that the relay had intercepted, I looked in the service manual and saw the blue/yellow wire was the correct wire to energize the starting circuit. I just soldered the blue/yellow wire back together and, BINGO, it started!

 

thanks for sharing the solution

 

You are welcome! It was SUCH a relief to get that old alarm out.

 

Glad you got it fixed ..

 

MEE TOO!!!! I had been worrying about that damm old alarm for years, wondering when it was gonna screw things up. Now I don't have to worry about it ever again.