Silver

I have searched the DTR forums, and also Googled, for an answer, but I am simply not finding an answer that matches the situation.

My truck, 1992 D250 (2WD) A-518 trans... when cold, it will not stay in overdrive. It sort of acts like it is searching for it (hope that makes sense). If I lock it out until I start seeing transmissions temps above 150-175 it will stay in, and will drive all day without any issues. I have read about the throttle position issues, but that just doesn't seem to jive with this issue. The transmission is a fresh rebuild, but it did this before, and the rebuild had no effect on it. It runs fine, and I can live with it, but I would like to know if there is a simple remedy such as possibly a temp switch replacement that thus far I have been unable to find. Thanks in Advance!

dodgenstein

There are two temp switches. One is in the engine head below the intake horn, this is the low temp cutout. The high temp cutout is in the trans cooler line just forward of the bell housing on the drivers side. The engine temp is an engine coolant sensor that allows OD after 120 degrees IIRC, the cooler line shuts things down at some ridiculously high temp of 270 degrees or so.

Silver

Thank you sir!!! The high-temp switch was a no-brainer. However, I am unsure as to the other one. I snapped a couple pics. You stated "below the intake horn" so I assume neither of the switches in the first photo (sw1) are what I am looking for. I snapped another at the best angle I could get of what I assume you are calling the "intake horn". Can you get me a little closer to what I am looking for? Again, Thanks in Advance!

torquefan

It's not either of the two pointing up in the first picture, it's lower than that. You'd be more likely to see it in the second picture, but I can't remember exactly where it is.

BC847

The Engine Coolant Thermal Switch related to the transmission is located in the head, just above the head/block seam (gasket), to the upper/right of the fuel filter/heater. It will be under the intake log of the head.










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j_martin

It's not inconceivable that the TPS would act up when cold, then be normal when warm.

Get some Deoxit-D5 into it through the pin hole that the end of the return spring is in. The connector to the TPS would benefit from the same stuff.

Get it at your local music/guitar store. They use it on the connectors to their audio equipment.

Rat Shack has small quantites at a big price.

Silver

Thanks for all the help guys... especially the diagrams!!! I saved them and will get back at this next chance I get. Gone to see the Doc tomorrow and it looks like maybe some elbow surgery coming... by spring I hope me and Old Betsy (Dodge) are both tickin' like a new Timex.