extra water temp sending unit? Do you mean attaching two wires to the same sending unit will affect the accuracy of the signal?! My car does not have an EFI setup like yours, do you think I would still have the same issue? I had been planning to have my SPAL fan piggy back on my Autometer temp sender unit instead of installing a second temp sending unit. When I test fit both senders on the intake, I did not like all the brass fittings (t-fitting, a male-male adapter & both senders) on the polished intake. Sounds like I may have to give it some more thought... hhmmm, maybe i could install one temp sending unit in the radiator drain plug hole? Any other ideas? Does anyone make a thermostat housing with an additional hole for a sending unit?