Ford Truck Enthusiasts Forums

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- 1997-2006 Expedition & Navigator (https://www.ford-trucks.com/forums/forum27/)

- - A4wd Light (https://www.ford-trucks.com/forums/106629-a4wd-light.html)

iam taking my expy in tomorrow morning for a scan to find the prob. and also have the codes cleared i will let you know whats wrong...mech. says sounds like speed sensors

Hey Tommy, let me know how you make out with it. My E-mail is the4by4freek(No Email Addresses In Posts!). I'm a little curious as to what they find. I don't have time to bring mine to the shop, between working a full time job and side business this truck never sits still long enough!

4by 4, i spent 5 hrs at the shop today they are not charging me anything they found that i had no 4 wheel drive.the drive shafts were engaging and spinning but the fronts would not spin. he found a vacumn leak on the front the lines sit on top of the front drive motor which is vacumn operated the line was broke...it worked after that but no fix on the blinking light.....it scanned out to be green wire from sensor behind the trans case sensor maybe part two next week on tues we are closer just have to find where the loss of ground is...he told me to go ahead and get the sensor that is behind the transfer case up by the shift motor..it is called speed sensor at the transfer case part number YL1Z-7F293-AA
SW-5586

Thats good news tommy. My 4x4 works fine, just no A4WD. You never mentioned that you had none at all, if you had I could have told you about the vaccuum lines. They run fron the passenger side firewall to the front axle. There is a splash shield over the canister that controlls the front axle. The speed sensors that he told you about were the same ones I mentioned in a previous post. If they are bad it will not work either. Keep me posted! Thanks

hi 4by 4, i was suprised also that i had no 4 wheel drive for i never use it now it works great all new lines...now if we can get the a4wd to work which would make the a4wd lite stop blinking..if we can just get someone who has had this problem..it is prob this sensor i bought

Like I said before Tommy, There are 2 sensors that run this system. There is one for the rear drive shaft and one for the front drive shaft. If either one of them is bad it will not work properly. They sense the speed on the shafts and if the rear spins faster than the front then it will engage a ball ramp valve in the transfer case and compensate for the diffrence. It will continue to compensate untill both drive shafts are spinning at the same speed. I found this info on a Ford Tech site. The guy was a master technician, and relayed this info, I hope this helps you out!

4by4, well its all fixed the a4wd light stays on now and all 4 wheels turn....it was the sensor on the transfer case the one that is easy to get too on the cone...the old one showed a rsistance of 133 ohms the new one showed 20 ohms...here is the part number to get at ford....YL1Z-7F293-AA...please keep me informed of what you do and find...

you have to clear the error code also the mech. can do that...this took about 20 min. to do the whole job

Thats great news Tommy. Now if I can just get mine into the shop I'll be all set. It seems that it never sits still long enough. It's my busy season, and the phone is ringing off the hook! Everyone wants to remodel thier homes!

I had a similar problem on my 97 EB. The A4WD light would blink. the 4WD Hi would come on steady. the 4WD Lo would come on steady and you would hear the motor engage the Lo gear. However, I had no 4WD in none of the 3 modes.

I took it to the dealer and they replaced the front axel speed sensor. Said that when spinning it by hand it was very erratic. That fixed the blinking A4WD light and I assumed everything else.

You would think that the dealer would test their fix to ensure the 4WD was engaging properly, but alas, they did not. The next snow we got, the *&$#(^@#( 4WD was not working. I was about to take it back to the dealer one day when I remember finding some smoked vacum tubing several weeks earlier. I wasn't sure what it was, but I did some investigating after I found the 4WD not to work and it was a vacum line from two solenoinds on the fire wall that went down to the front transfer case. According to the parts guy at the dealer, these vacum lines are used to lock the front hubs. They wanted $75 for the two moulded tubes, one blue and one pink. I went down the street and bought some normal rubber line and voila!, I got 4WD again.

A lesson learned: Correcting one problem with a system does not mean there aren't others in the same system. Make sure the dealer checks it next time after the "fix" it.

when my a4wd kept blinking, in trying to find the problem ,they also found no 4wd at all even when those lights stayed on so he checked all the working parts and they were all good so the problem was a leak in the vacumn line that goes to the front axel and connects to the mods on the pass. side fire wall he just replaced the bad line and tested the other one...that fixed it i had 4wd...
now for the blinking a4wd light he checked the resistance on the transfer case by the cone there is a sensor it was bad so he replaced that and that took care of the problems.....they didn't chg me a thing..i bought the sensor for 32 bucks at ford from a friend of mine.

Sounds like me and boxcar_tommie22 had the same problem.