Subject: [FlyRotary] Re: EM2 users

 

        I recently installed a set of VDO sensors in these inputs to measure oil pan & coolant in. Neither are working. I've input the scale factor & offset from the other liquid temp sensors, but these both read 281F regardless of temp. I've switched sensor inputs to confirm sensor operation. I've measured the circuit resistance and found both aux. liquid circuit inputs to be ~450 ohms, while the main liquid temp input circuits are <100 ohms. I've been meaning to call Tracy about this, but I've just been too damn busy.

S. Todd Bartrim 
 

Stand by.  I may know this one.  My previously mentioned failing memory (we think the MRI magnets do this) seems to recall something special that had to be done to some of the inputs.  If I'm correct, the aux temps were the ones that needed a pull-up resistor added.  I'm heading to the hanger in a few minutes, so I'll look through my info at the hanger, and try to find the details.  I sure hope I didn't throw this away when I got the new manual. 

Cheers,

Rusty (at least mine work)  

My results were the same as Todd’s.  I’m using a VDO temp sender for oil before the cooler.  Tracy specified 200 Ohms in series and 200 Ohms in parallel to ground.  It still reads 279 at room temp.  Aux LT3 is grounded – it reads 281.  I tried changing scale factors on LT2, and the reading changed on LT3

Anyway, it’s good to know that it is not just on mine.  I’m sure Tracy can straighten it out.

Thanks,

al