I need help with 4 wheel drive!

I live in northern Minnesota and the 4 wheel drive on my 1989 GMC Jimmy stopped working. I leave it in 4WD all winter, it was fine until it sat in a heated garage for a weekend. Is there fluid or anything that I have to check? Help!

Full-size or S-series Jimmy?

Is this electronic 4wd or is there a shift lever on the floor? If this is a full-size it’s definitely not electronic.

You shouldn’t leave it in 4wd all winter; You have to take it out when on high traction surfaces like dry pavement or concrete.

There is a shift lever on the floor. I rarely find dry pavement in my town, so that’s why it’s always in 4WD. I think it’s an S-series.

I live in northern Minnesota and the 4 wheel drive on my 1989 GMC Jimmy stopped working. I leave it in 4WD all winter,

This is a part-time 4wd system right??? Am I reading you correctly that you leave it in 4wd ALL the time during the winter??? You NEVER shift it out of 4wd??

If so…then you could be destroying your transfercase.

I only take it out for long trips and in the spring when the roads get clear. We don’t have freeways and our road are not traveled enough to get them dry in the winter. It’s in 2WD all spring, summer and fall though.

Unless the roads are very slick or covered in snow…then what you’re doing can easily DESTROY a transfercase. I suggest you find the owners manual and read the section on how to operate the 4wd system. Minnesota doesn’t come close to amount of snow the town I grew up in (they don’t even get as much snow as we do here in NH)…and I couldn’t run my 4wd vehicles in 4wd all winter long without doing serious damage to the transfercase.

What are the symptoms that it “stopped working”? Is there a light on the dashboard that went off, or maybe by driving it around?