I just bought this 02 f-150 supercrew 4x4 from a friend. Th e problem just started today. The 4x4 light started blinking and the radio and pwr windows stop working when I put it into drive. When I put it back into park, everything works again. I don't know if this has anything to do with it or not but I had an ac power converter plugged in. I have replaced the battery to no avail. I thought it might be a relay or fuse but don't know which one. Can anyone help.

 

I just had a similar problem where all the dash lights/instruments were flashing and doing strange things. Eventually it wouldn't start unless jumped and then the battery died completely.
It needed a new Alternator and/or voltage regulator (most of the time one in the same).

 

Check for water intrusion in the GEM.

 

I'd ask your buddy if he noticed this problem while he owned it, chances are your not the first person to experience it on this truck. I'd give him the benefit of the doubt that he is an honest person...after all your friends for a reason! If this is a VERY recent purchase/transaction I am sure he will step up and offer to fix problem himself.

 

you never know tho, i bought my first car when i was in high school off of a teacher, and i had all sorts of problems shortly thereafter, and he didn't give a ****. i guess it just depends on the person's integrity. hopefully your friend has a good amount.

 

The guy I bought it from said that while the temps were down in the single digits here and I think we may have had some snow at the time, the radio would not work. He thought it was the battery but it did not act up again. I checked the window seal and the seal appears to be deteriorated around the corner of the windshield. I looked under the dash and can see a little bit of what looks like corrosion from the little crack where the two pieces of the gem or fuse box close together ( I cant tell the difference between the two). The problems are no longer there so should I just replace the seal and or windshield and hope the problems don't come back or should I pull the fuse box and gem and spray some wd-40 on the contacts? If I pull the Gem box can I just plug it back in?

 

I had the exact problem happen to my 02 supercab 4x4 and the issue was a small leak on the driver's side windshield. After every rain/snow I could count on some water being on my floormats. I took it to a local glass shop and had them run a test on the windshield and they verified the leak and sealed the entire windshield for $75. I would get this repair done as quickly as possible because replacing the GEM costs about $1300 and can only be done at a dealership.