4wd Flashing Lights

[RammaR]

I hardly ever use the 4wd auto setting on my '96, but yesterday we had a ton of rain so I figured why not. After serveral miles the 4wd and 4wd LO lights started to flash 6 times and then go out for a few minutes then would flash again. No strange noises... and it still felt like I was in 4wd auto at the time. I switched back to 2wd and everything seems fine.

I've done some searching here and found several threads about the O/D flashing lights and replacing the GEM if the windows don't work. Mine work fine and the O/D light never flashed - so I hope I'm safe there.

Did find part of one thread that said something about a "transaxle speed sensor". Anyone know how to tell if this might be my real problem? Do you have to get them from Ford, any idea on how much it is? I hope there's only 1 a few weeks ago I had to replace and O2 sensor and discovered there are actually 4 - thats gonna hurt later i'm sure.

Thanks for any advice you can lend. Going out of town with it next week, anyone think its going to hurt things if I keep it in 2wd?

 

[yob_yeknom]

It won't hurt anything to leave it in 2wd. When there is a problem with the system, it defaults itselft to 2wd.

 

[TPLYNCH]

The # and frequency of the flashes relate to a code. If it comes back, you can use that to diagnose the problem. Do you put the system in 4-lo at least once every couple of months?? Have you tried since the flashing lights started? It's good to do this just to keep the system lubricated so you don't get stuck when you need it most. When the lights flash in Auto, it probably indicates a problem with a speed sensor.

 

[RammaR]

Thanks.. i've tried it it again the the 4wd light comes on normal for awhile - thought I was out of the woods - but then started flashing again. I have to put it in 2wd and restart to clear the flashing problem I think.

Both lights blink 6 times then delay for a minute or two and blink again. I haven't had it in 4-lo but maybe once since I bought it over a year ago. Just broke 100K miles so I should have the trans fluid changed probably. Any idea on how to tell which sensor it is? I think I've read there are two. Or how hard it is to replace.

Thanks again

 

[Fred Garvin]

Before you take it in to have it looked over, reset the computer by disconnecting the battery, waiting a bit, and then reconnecting it.

Start the beast up, and see if the flashing stops.

Sometimes, the computer gets a goofy signal from somewhere and needs to be reset.

Also, you really should engage the 4WD at least once a month to keep the shift motor from seizing.

 

[Jason_25]

Yeah definitely throw it into low range and drive for a few feet once every month or so. The wheel speed sensors on your transfer case are probably bad.

 

[GaryGnu]

Any luck?

RammaR, any luck with this problem? I'm having the exact same problem with my 96...

 

[RammaR]

After checking with Autozone for a replacement sensor, they said there were 2 for each postion (front and rear) so I'd have to pull it out and bring it in. Since that was still just a guess at what the problem was I ended up taking it into my local dealer and had them run their diagnostic check. It turned out that the rear speed sensor was showing 5 mph slower than the front so that was what was triggering the light. It was $75.00 for the test but if I wanted them to replace the sensor they would apply that. So it was about $130 total I think out the door.

I don't know of a good way to test if a sensor is or not so if you want to tackle the job yourself you'll probably have to pull out both sensors. Then take them to a parts store so they get match up the part numbers. I want to say they were about $26.00 each from Autozone so it would be a little cheaper.

Oh, one other thought - if the number of flashes is specific to the problem. Just swap out the rear speed sensor first - its easier to get at anyway.

Its been several months now and my 4wd system works great. So that was definately the problem.
Good Luck