My newly acquired 97 4X4 is not shifting into OD. Any ideas? IF the OD button on the gear selector lever is messed up will that cause it? The OD OFF light on the dash is NOT illuminated either.

What's the temp outside?

It has to meet a minimum temp to go into OD. I forget the exact number, but given the temps in AK right now (I saw a video of your 5 hour day couple days ago) I highly doubt it's getting to operating temp.

I wish we had a 5 hour day!! The 21st was the solstice, with a possibility of 3 1/2 hours of sunlight.....Maybe 5 hours with dawn and dusk thrown in. nevertheless, I'm sure when the motor has been running for a while it would bring the tranny up to temp enough for proper operation. IF the OD unit is malfunctioning would it throw a code? The other shifts seem smooth enough. Do you know what the RPM's should be at specific speeds?

I believe it's 100°F, I read somewhere.

I'm sure if the actual OD unit was messed up you'd get a code. As everyone else said, the trans won't go into overdrive until warmed up to a certain temperature. Mine does it all winter long. I think that most likely the actual switch on the shifter is bad.

I just pulled it apart..........The wires were NOT even hooked up at all! As I sat in the driveway with it running I touched the wires together and the OD OFF light came on. Then touched them together again and it went off. So IF the switch was hooked up properly it should work better?. it still doesn't explain while driving it's still not shifting into 4th, even with the OD light off. I did notice just tonight that right where it SHOULD shift the CEL flashes for a few times then goes back to constant ON. Is there a way to get the codes from how many times the light flashes? I've heard with the 97's you can do that.

Well if the CEL is flashing there may be something going on with the OD unit. But still hook up the switch, see what happens when you do so. It certainly can't hurt.

As far as checking codes, put the key in the ignition, turn it to the position just before start and then back off. Do that a total of 2 times and then the 3rd time turn it to that position just before start, and the codes should come up in the odometer. Post those codes on this thread and one of us can tell you what they mean. Or just google the codes lol

Tried the key thing and nothing came up on my odometer but what is always there?? BTW my odometer is not the green LED it's the black dimmer ones. Maybe that trick doesn't work on 97s?

So, the CEL was never on initially. You fixed the wiring in the switch and now the CEL flashes and stays on. Sounds like the one that sold it knew something was wrong(?). You say newly acquired.

The key switch trick works on my '01, not sure of same Gen or not. You have to do it quick like. I forget the sequence fully since I purchased an OBD tool.

Good luck!

I forgot that the 97's have the older odometer so no, that method won't work. If you can, go to your local auto parts store and they'll be able to tell you what code(s) it is throwing. If not, order an OBDII scanner from somewhere online and then you'll have it (it's a pretty handy tool to have around, you'll use it more than once).