Hey guys,

This one has me baffled. I have a 1999 4WD expedition with the A4WD system. The system was working fine last week puts is not any longer. When I swith from A4WD nothing happens. No lights, no relay double click, no 4WD. I cant even get the A4WD to engage on slippery surfaces. I have taken the switch apart and cleaned the contacts and I have checked all the fuses. I purchased a new GEM module today but have not yet installed it. Does anyone have any idea what might cause this. I am going to be out of ideas if the GEM module doesnt do the trick.

Thanks for your help!

Brian

 

Did you check the fuse for the A4WD system? Since you're not getting any lights on the dash or any relay clicking & engagement, I'd check the fuse as a starting place.

 

You may want to invest in a Multimeter. You can find then relatively cheap. I would use it to determine if you have voltage to the A4WD switch (with the ignition turned on). Next I would determine that you have voltage coming out of your switch. If voltage is present in and out, I would next check for voltage at the A4WD switching motor. This will help you rule out possibilities. Reading your post, you stated the dash light doesn't light 4WD, sounds like there is no power to the switch.

Hope this helps.

 

This thing turned out to be a nightmare. The GEM module was fried. They replaced it and still no 4WD. The shift motor was also bad. That was also replaced and now the 4WD works. whew.... What a pain.

Thanks to all for your replies!

Brian

 

Just outta curiosity...How much that run ya to have it done?
Scott

 

all together about $1k. GEM module, shift motor, fluch transfer case and program GEM....

 

ouch...i figured not cheap
Scott