I have a 4 wheel drive and my transfer case won’t shift into gear. It doesn’t happen all the time though. Sometimes it works perfectly, and then my rear wiper won’t work or the tow away button won’t engage. And when these happen my truck will not shift gears either. Then I will be stuck in first gear. I don’t ever know when it’s going to happen either. When I’ve taken it to the dealership to be checked out they don’t find anything wrong. I’ve checked the fuses for the transmission, electronics, transfer case, alarm, etc. and everything is OK. I’m wondering if it might be the relay. Then one time I was driving real slow in the neighborhood, and I pushed the rear wiper and the lights lit up, and the car shifted gears. I just can’t figure this out, and it’s driving me nuts. Do you have any suggestions?
There seems to be a deep electrical bug in the vehicle and unfortunately these problems require a case study of the vehicle. Some facilities will offer the service where they will keep the vehicle overnight and drive it in an attempt to have the problem show up. Intermittent problems like these can be caused by unseen corrosion inside of relays and circuit in control modules. Each circuit must be inspected down to the wiring.