Engine/Transmission (1994 - 1998) 47RH Temp Sender?

[Cummins4Life]

I know this has been beat to death but even after searching I've been unable to find the two pieces of information that I need.



1. What size NPT is the factory temp sender in the hot line going to the heat exchanger.



2. If I wanted to disable the factory sender with a resistor. What value resistor would I use. I've read both 7. 5Kohm and 100ohm.



So far I have tried the sender in the pan and the second test port on the passengers side. The pan yielded hotter temps on average which also fluctuated more than the 2nd test port. So I'm either going to "T" in at the factory sender so both the OE sender and my autometer temp sender can be used or just simply disable the OE unit in favor of of the AM gauge.

 

[Howard Durand]

According to my measurements the sender is a 3/8-18 NPT.



I am not sure what temperature the PCM wants to see coming from the converter but probably around 75 degrees F would be OK since there is no delay in the summer time.

For that, you would need about a 10,000 ohm resistor to match that of the sender.



At 0 degrees, the resistance of the sender is between 29,000 and 35,000 ohms.

At 100 degeees, the resistance is between 5,000 and 5,500 ohms.

At 212 degrees, it is about 700 ohms.



Hope this helps.



I personally wouldn't use a tee because I don't think you can get good fluid flow past the probes of either of the senders.

 

[RBratby]

from what i was told the pcm wants to see about 100* before it will let you go into lock up.

 

[ronco]

When I removed my factory sending unit to install a gauge, I could only find a 670 OHM resistor. This worked fine and allowed the PCM to work normally. HTH





Ronco

 

[Cummins4Life]

Thanks guys, picked up a T and some 1k ohm resistors. Intend to try both and compare.