ISSPRO Trans temp sending unit trouble

[Matt400]

I have an ISSPRO trans temp gauge 100-280 that I have never been able to get a reading from,

needle always stays pegged on 100 yet I know the transmission output line is hotter than that.

Anyone have a resistance measurement for the sending unit so I can test it?

 

[Pliska]

Matt,

If you want to check the resistance, it should be as follows (hopefully the formatting comes out okay on this):

Temp°F Resistance Tolerance (ohms)

100 1115 ±22

160 1393 ±31

220 1723 ±120

280 2076 ±163



You should also check the electrical connections, both at the connector by the sensor and at the amplifier box (the little screw terminals). If you check these things out and it appears to be malfunctioning, definitely send it back. Our warranty people ask that we process it through the dealer you purchased it from, so their tracking system doesn't get screwed up.



Thanks,

Michael Pliska

 

[Matt400]

Just what I needed, thanks Michael!

 

[Matt400]

Update-

Since the resistance goes up with heat shouldn't the gauge peg with the sensor disconnected?



I tested from room temp up to 212 and the resistance is right in there with those specs.

On the truck I had it "in the fluid" using the output line till the line started leaking then switched to this:

#ad




The instructions say to use anti-seize between the line and adapter for heat transfer which I did but nothing about inside the adapter. I filled the empty cavity inside the adapter where the sensor tip screws into also with anti seize.



I will double check the amplifier box.

 

[Pliska]

Matt,

The circuit design responds with a zero value display for drastically out-of-range signals (either low or high).



I agree the cavity in the adapter should be filled with some type of thermally conductive compound. Using that adapter, the reading will definitely be lower than the actual fluid measurement. How much lower will be dependent on the thermal conductivity and ambient temperature. I may have to pick one up and run some lab tests on it.



Regards,

Michael Pliska

 

[Matt400]

You should also check the electrical connections, at the amplifier box (the little screw terminals).

Thats where I found my trouble, original install error- all working well now. Thanks!

 

[PSteinis]

Same problem but I don't have an amplifier box. Does this come with the gage and sensor?

 

[Pliska]

Are you having a similar problem but with a gauge which does not use an amplifier box? What part number is the gauge?



Thanks,

Michael Pliska

 

[PSteinis]

Yes,it only reads 100* and barely moves. I don't know the part # of the gage as it has been awhile. I just checked,it is a lunar series temp gage by Auto Meter. If my memory serves me correct,there was only one wire between the gage and probe.