wiring ? - Hi, On my 1999 silverado 2500 i just put a rebuilt transfercase. Now my speedometer is stuck on 100 mph also shifts very hard. Did not have ...

Hi,

On my 1999 silverado 2500 i just put a rebuilt transfercase. Now my speedometer is stuck on 100 mph also shifts very hard. Did not have these problems before the swap. I am worried i have the three 2 wire sensor wires messed up. But not sure which sensor is what. Thanks for any help need this truck for plowing.

Are you sure you did not pinch a wire between the transfer case and the transmission?

Thanks for answering. Yes there are no wires pinched i have checked that also have tried switching plugs but nothing changes. I am thinking maybe i should put sensors out of my old transfercase into the new one. Does anyone know where i can get a wire diagram to tell me what color wires go to each sensor. Thanks again.

I don't know where to get a wiring diagram, however, yours being a 2007 the wires should be kind of "moulded" to the spot the origionally went to. I would definatly try usuing your known good sensors.

I don't know where to get a wiring diagram, however, yours being a 2007 the wires should be kind of "moulded" to the spot the origionally went to. I would definatly try usuing your known good sensors.

Ok i will swap them hopefully tonight after work. But this problem is with my 1999 not my 2007. Thanks i will let you know.

In that case the wires should really be formed to where they went.

Checked wires and they seem to be where they layed since 1999. Swapped out all three sensors from my old transfer case and checked to make sure connections were all good. Also put in a new transfer case motor. Now speedometer is back to 0 but will not read when moving. In 2wd service 4wd light stays off and no codes. When i put in 4 hi service 4wd light comes on code 0300 rear prop shaft malfunction. Also if i try to put in 4 low it will not go in all lights go out on switch. Code 0387 unable to complete shift comes on. I have to pull fuse to be able to get switch working again. I guess I am really lost on this one. I had none of these problems until i switched transfer case. Old transfer case was slipping. Front shaft would not turn under load.Do you think it has to be reflashed because of the different transfer case and motor? Thank you for any help.

It kind of sounds like there is no signal coming from the vehicle speed sensor. I'm pretty sure that is located on the output shaft to the rear shaft of the transfer case. I'll bet that there is a problem within the new case. Maybe they forgot to install the pulse generator onto the output shaft. I'd bet all of the symptoms are related to one problem.I'm sure you would not have to reflash a computer for installing a new transfer case.

Thanks for all your help. I went to my local gm dealer and they gave me a wiring diagram. Armed with that I re traced all the wires and found the mistake. Boy do I feel dumb now. That fixed the speedometer problem.Now I just have to put front driveshaft back in and make sure it shifts ok. Hopefully its good to go. Thans again.