Hey everyone, I'm brand new to this site and looking for some assistance on my 1991.5 dodge d350, I just got it and it's my first diesel, I'm actually looking for a wiring diagram if anyone has one. the problem is I have no overdrive. I've checked the tps and it looks to be operating perfect, checked each wire at the od module and it seems good. It's getting 12v to the od solenoid. While checking the connector while unplugged from the trans temp sensor i'm only getting about 1v, I believe it should be 5v, correct? I ohmed out the red/white wire from the connector up top to the trans temp sensor plug and I have continuity, then I ohmed out the orange/black wire, I think I got around 8 ohms of resistance, so i'm assuming I have a short. If anyone has a diagram or some feed back i'd appreciate it, thanks.

 

try dropping the trans pan, the wires for the od sensor run across the valve body and can rub on it and ground out, happened to me on a 90 dodge that i had.

 

I thought i had a wiring problem to the trans temp sensor but after tracing some wiring found that the coolant temp sensor is in series with the trans temp sensor, still trying to figure out the od problem, does anyone have a diagram for at least the overdrive circuit and related components or know where i could get a diagram, i've been searching the web with no luck, i'm going nuts trying to figure this one out, any help would be appreciated.