Gem modules aren't working for long. I want to put toggle switches on my dash for hi and lo 4wd. I've heard it done. Could anyone give me some advice or on which wires to plug into by the t case. 99 f350
It could be done, but it would probably be more work and cost more than replacing the GEM. You'd have to wire in the feedback (position) switch on the t-case motor somehow to be able to be sure the motor stopped in the gear you were aiming for. It's not just flip a switch and it goes to the right gear. The position switch turns the motor off as it reaches the correct position based on what the GEM tells it to do.
You'd have to duplicate the logic in the GEM with switches and relays.
I've replaced the gem once from a eBay seller. Came off a automatic so I didn't have 4lo... After awhile it did what my old one did. Drive down the road and the 4wd drive dash light would be on without me touching anything or it being engaged.
Also, does anyone know where I can get a new t-case electrical connector. I guess it would be the "female end". The plastic is broke and doesn't give me the best connection. I would have to turn on 4wd then go under the truck and bump the connector. After that I'd hear it go into gear.
Ford should be able to get you a replacement pigtail for the t-case motor connector. They have a catalog of pigtails with pictures in it so you can match them up. http://www.fordservicecontent.com/pubs/content/connectors/images/connectorcatalog.pdf
If your connector isn't making good contact, that could be the root of your problem. It needs to send signals to the GEM, and if it can't do that, then the GEM (which may be just fine) won't know what to do.
You should go thru a structured troubleshooting procedure to find the actual problem.