Mark VIII elec fan. 3 wire lead? [Archive] - Chevelle Tech

: Mark VIII elec fan. 3 wire lead?


JOHN WILSON
May 9th, 01, 6:55 PM
Today I bought one of the highly recommended Mark VIII fans. While at the shop I noticed the connector on the fan motor had 3 leads. The guy at the shop tells me that one is ground and the other 2 are for fan speed (high and low). When I got it home I just hooked it up to make sure everything worked before I started grinding and cutting on the fan housing. I hooked the ground lead and positive lead as they were marked on the connector (the two prongs on the outside). The fan fired right up no problems. When I hooked the + lead to the center terminal there was nothing. Is the center terminal actually a + lead or was the guy at the shop wrong. Or, do both + terminals need to be hooked up at the same time instead of just one or the other?

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Coppertop
May 9th, 01, 7:15 PM
Going over past posts concerning this fan... it seems 99.9% of people on this website use the outside terminals only. (the ones actually marked "+" and "-"). The middle doesn't get messed with. I'd go that route personally, and wouldn't mess with the center terminal. Leave it disconnected.

cjlandry
May 9th, 01, 9:03 PM
Someone posted a link to a Mustang guys site a few days ago. The guy goes into some detail about the functions of the terminals and how the relays function on the stock application. It seems that one has something to do with whether the AC is on or not.

The site also has a schematic on how to make an inexpensive oxygen sensor.

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Wes Colby
May 9th, 01, 9:41 PM
John, you've got mail.

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glenn396
May 17th, 01, 11:16 AM
According to the 1996 Mark VIII electrical schematic, the 3 pin connector at the fan has a Ground, a power feed from the Variable Load Control Module (which provides low or high speed) and a "dummy" wire that goes open/terminates in the harness. The VLCM duty cycles the power on the fan motor to provide different speeds. Give it 12v and let it go!