Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: len.barron on October 17, 2020, 04:58:16 pm

Title: Transmission Temperature Sender Resistance
Post by: len.barron on October 17, 2020, 04:58:16 pm
My coach has the originally outfitted Stewart Warner gauge set. Transmission temp(150-350 gauge range) is reading excessively high, when compared with an IR gun it is reading 80-100dgs high. Normal flat land driving is registering 240dgs (everything shifting perfect, engine coolant temp below 180dg) . You can pull the dipstick and wipe the fluid in your fingers and tell it's maybe 140-ish.. The sender (at 75dgs) reads 2300ohms, I've disconnected it and simulated some differing resistance values to the guage and it seems to track really well from 600ohms (close to 150dg) down to 150ohms (275dgs). Does anyone have the actual sender resistance specs? or the actual sender part number?
Thanks
Title: Re: Transmission Temperature Sender Resistance
Post by: gracerace on October 17, 2020, 05:27:46 pm
My coach has the originally outfitted Stewart Warner gauge set. Transmission temp(150-350 gauge range) is reading excessively high, when compared with an IR gun it is reading 80-100dgs high. Normal flat land driving is registering 240dgs (everything shifting perfect, engine coolant temp below 180dg) . You can pull the dipstick and wipe the fluid in your fingers and tell it's maybe 140-ish.. The sender (at 75dgs) reads 2300ohms, I've disconnected it and simulated some differing resistance values to the guage and it seems to track really well from 600ohms (close to 150dg) down to 150ohms (275dgs). Does anyone have the actual sender resistance specs? or the actual sender part number?
Thanks

I don't have spec's for your trans, but went through this with the retarder sensor on ours.

No matter how much I bench tested, it OMH'd fine. I just bought a new one, and it solved the problem.

Chris
Title: Re: Transmission Temperature Sender Resistance
Post by: len.barron on October 20, 2020, 10:51:42 am
I found what I believe to be the closest Stewart Warner sender(280EE-F) available. It is a 140-320dg sender, my SW gauge is 150-350dg. $20 shipped from ebay so it's worth a shot.
Title: Re: Transmission Temperature Sender Resistance
Post by: len.barron on October 25, 2020, 10:58:51 am
Installed the new SW 280EE-F sender and that fixed it. I tested the resistance of the new unit and compared it to the old, about 73dg yesterday, new sender was 8200ohms, old sender was 2300ohms...with the resistance decreasing as they warm up it's pretty easy to see why  I had 80-100dg higher than actual temp display.
I also found the original part number on the old unit, it is a Datcon 02025-00, it also is listed as a 140-320dg sender.
Title: Re: Transmission Temperature Sender Resistance
Post by: gracerace on October 25, 2020, 12:01:10 pm
Good job, thanks for leaving all the info and part numbers, it will help people in the future.

I wish others would post resolves.

I have read  long posts, with no resolve.

CW