water temp sending unit??
 

are the sending units for electrical gauges the same????is it a merc part or do you need to get the one that goes with your type of gauge???

You need one that matches your guage, water temp are mostly of the 240-33 ohm type but there are others. VDO are different as are some other brands and there are dif ranges 220degF 250 degF etc. Oil temp senders have even more flavours.

Depends on the gauges your useing. I know the merc stuff should work with the Gaffrig stuff. But VDO wont. neither will the OMC senders with Gaffrig. I found that out after redoing the dash on my dads deck boat. Gauges were acting WAY goofy. And i thought OMC was a division of Merc or maybe they used the same stuff here and there! Oh well... :cool: