2002 Ford Explorer inertia switch keeps tripping.

[jgianettino]

I had replaced my radiater a few weeks ago, when I went to start the car it ran than stalled, I looked though my book, and found my inertia switch tripped, I reset it, and everything has been fine ,about three weeks later I stopped at a local store when I came out the car would not start again, The switch tripped again, has anyone ever had this happen to them, ? Is the switch bad? I would think that this type of switch would be very durable and would last forever,, or is there another underlying problem?

 

[RKH58]

Welcome to the Forums

Could be a number of things. Until someone a little more in the know shows up try searching "inertia switch", lots of threads there, you might get a headstart on your fix. Good luck!

 

[jgianettino]

I called Foed and they stated the switch is bad, 29 bucks, it may be worth it, but I have also read it may be a short in the front wireing harness??

 

[BrooklynBay]

Welcome to this forum! I've renamed your thread, and moved it into the stock 2002-2005 section. This is an odd problem. These switches aren't supposed to trip except in a crash. Even then, they don't always trip when they should. I don't know if this is true or not, but I read some place that these were originally designed for bombs. They would trip on impact, and detonate the explosive. This is the opposite of the way they are made for our vehicles. They are normally closed (electrically), then open the circuit when the internal ball strikes a target. The button on the top resets the mechanism. They were designed by a company called First Inertia, and have been in use since the early 80's. Bombs now use accelerometers similar to air bag crash sensors. Each one is designed for a specific "G" force. Analog Devices has a part number ADSL50 to represent 50 as the G force of this part. The inertia switch is very basic in comparison. It could trip if you hit a hard bump, but an accelerometer is usually able to make a distinction. I know somebody that hit a bump, and his air bag deployed, so not everything is false trigger proof.

 

[jgianettino]

Thanks, for the info, I just find it hard to belive that this switch would be bad, funny right after removeing the rad, and then again a few weeks later being triped, some other threads I read stated after a guy was done draining his trans oil the same thing happend, almost like there is something esle under the hood that if something gets wet it trips it, I will replace it first and see how it goes, for 29 bucks that is not a bad start...

 

[BrooklynBay]

Any junk yard with a Ford vehicle will have one. You could probably get it for a few dollars. The style might be different, so just compare the one you have.

 

[jgianettino]

Yea I know, but the few extra bucks at least I know the new one is working, and if it trips again i will go from there, If I get if from the junk yard my luck that one would be bad also and then I would be replaceing something else... thinking that one is ok,,, I just hope it is not a short causeing it to trip out, then I have to find that...

 

[BrooklynBay]

It is very rare for one of these to go bad. Most yards will give you a week to return it if it's no good anyway. You could also contact KBabiak. He's a vendor on this site for used parts. Torrie is a new parts vendor. His site is WWW.FastPartsNetwork.Com. He might have one for less than the dealer. One more vendor to try is WWW.RockAuto.Com. There is a coupon code in the vendor's section for them. They usually have good prices.