97 ford explorer blinking 4wd and 4wdlow lights

The blinking 4WD lights is a signal from the computer (the "GEM") that runs the Control Trac 4WD system that things are not well. Basically, the system monitors the speeds of the rear and front driveshafts to see if the rear wheels are going faster than the front. If they are, it means they are slipping and the system will increase the power going to the front wheels. It does this in steps until the front and rear driveshafts are essentially locked together. At that point, if the rear still seems to be going faster, the system figures this just cannot be and shuts off, flashing the lights to indicate the problem. The way the speeds are monitored are with speed sensors in the transfer case that splits the power from the engine between the front and the rear wheels. Usually, this problem is one of the sensors has failed, or the electrical contacts are dirty, or the "tone wheel" that the sensor monitors is crudded up with gunk. It is not terribly expensive to replace any of these sensors, and this can be done without having to remove the transfer case or transmission or anything like that. There are other things that it could be, and that are more expensive to repair, but they are more rare failures. Some less-than-honest repair shops will try to replace the whole transfer case, or the computer, but that is not normally needed.

The blinking lights shouldn't, by the way, cause you any problem except you don't have 4WD.

=Vic= Bear Gap, PA

Vic, Thank you so much for your reply back to me, finally I have found someone who is not out to take my money. Now when I take it to the dealership at least I can tell them what I would like to try first instead of them selling me on the most expensive fix that it may not even need. I will keep you posted on what they say and do, again thank you so much this mom appreciates it more than you will ever know.

thank you soccermomct

Vic Kle>The blinking 4WD lights is a signal from the computer (the "GEM") that runs

The problem is most likely a sensor located in the transfer case. Cost of the sensor is 17.00. Thats what happen to mine last year, it was an easy fix that took less then 15 min. The hardest part is crawling under the vehicle if you do not have a lift as I did.

Searcher

thank you so much you guys are the best and put my mind at ease, I feel like a woman who is informed . Is changing the sensor that hard for me to do?

soccermomct

No, you really shouldn't have a problem doing it yourself. If you are at all mechanically inclined. I believe it is one bolt holding it in there and an electrical plug.

Searcher

Ask around and find an independent honest, competent shop. I'm sure there are some honest competent dealerships but in my experience it's the small mom and pop shops that will more likely repair what needs repair and not what doesn't. I found a great shop I've been happy with for years. Where are you located? Ask friends, relatives, gas station employees, etc.

Hello, Searcher! You wrote on Fri, 17 Mar 2006 23:45:49 GMT:

S> No, you really shouldn't have a problem doing it yourself. If you S> are at all mechanically inclined. I believe it is one bolt holding S> it in there and an electrical plug.

S> Searcher

Not hard to do yourself, but, you need to know where they are. A manual should be available at your local library. My advice is to clean the metallic sludge off of them and reinstall, unless a wire is broken they can't really go bad. The sludge that is on them is small metal bits that have worn off of the gears over the years (they are magnetic sensors). If you want to do this once, instead of every few months, drain and replace the fluid in the transfer case. This will clean out the sludge in the fluid, I think there is an impoved fluid compared to the one that was original. Check the dealer on this though. The new fluid can be put in with a turkey baster, its messy but the clutch packs in the transfer case will thank you for it.

With best regards, Tom Amundsen. E-mail: snipped-for-privacy@comcastAWAY.net