Log in

View Full Version : Wiring Question MIV with Holly Sniper



JL1744
07-03-2021, 11:10 AM
Basic question I am sure but.. The wires for the sending unit / Electric choke that come with the F5 harness, they include
Oil temp-
Oil Pressure-
Water temp-
Fan Thermo switch
Electric choke.

I am not sure what to do with all of these wires. I am running a Holly Sniper. My guess is...

Oil temp - not needed
Oil Pressure - not needed because I have an oil pressure sending unit that goes to my Vintage Pressure gauge
Water temp - I have a temp sensor that also goes to my Vintage water temp gauge
Fan Thermo switch - Not sure about this as the Sniper has a temp sensor as well
Electric choke. - Not sure about this

Any advice is appreciated, I'm so close to firing the motor up...150303150304

phileas_fogg
07-03-2021, 11:30 AM
With the Speedhut gauges & the Sniper controlling the fan, you don’t need any of the wires in the Sending Units harness.

Oil temp: not used (use wire provided with gauge).
Oil pressure: not used (use wire provided with gauge).
Water temp: not used (use wire provided with gauge).
Fan thermo switch: connect to the Fan #1 wire on your Sniper system to have the Sniper control your fan; otherwise connect to the sensor provided with your kit that goes on the radiator. Note that there are two Fan thermo switch wires…one behind the dash (that’s the one you want) & one in the Sending Units harness (that you’ll remove if you want Sniper to control the fan).
Electric choke: repurpose for power to something else, like seat heaters. I can’t remember if this wire has power at CRANK; if it does, you can use it to power your coil or CD box.

Note that you need two water temperature sensors…one for the Sniper & one for the gauge. You can’t use a single sensor to drive both. You want the Sniper sensor to be located at the front left of your intake. The gauge sensor goes “somewhere else”; I put mine in a port in the thermostat housing. Doing so I don’t get an accurate temperature reading until the thermostat opens up, but I’m OK with that.

John

P.S. For the unused wires, either de-pin them from the connector & remove them from the harness, or fold the end back on itself & cover with heat shrink. You don’t want a loose copper end to have any chance to create an electrical gremlin.

JL1744
07-03-2021, 12:07 PM
John, Thank you!! For some reason I have been hung up on this for to long..
Time to get back in the garage.

Thanks again.
Jim