73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: DFAA on July 19, 2009, 11:03:42 pm

Title: Air Gap + Automatic Electric Fans
Post by: DFAA on July 19, 2009, 11:03:42 pm
Just thought I would share, maybe it will help someone out:

The last few days I have been fighting my electric fans trying to get them to come on automatically when needed. I had everything wired correctly through relays, and they would switch on manually, but would not come on by themselves.

I have an Edelbrock air gap intake. the only 3/8 NTP(NPT?) holes are at the rear of the intake. The only fan control sending units I have seen are all 3/8.  Intake also has two 5/8(i think) holes in the front. My water temp gauge sending unit is located at the front of the intake (5/8), next to the water neck.

I let my engine (.060 350)get well above the point where the fans should have come on(around 220 according to temp gauge), but they never did.

Point is: with the fan control sensor at the back of the intake, it never got hot enough to activate(ground), so the fans never came on. I went to the auto parts store and bought a 3/8 to 5/8 adapter, moved the sensor to the front of the intake, now the fans come on automatically (coming on at 195, off at 180, which is a little higher than the sensor states (185/170))

hth,

Dan
 
Title: Re: Air Gap + Automatic Electric Fans
Post by: VileZambonie on July 20, 2009, 06:47:45 am
Just get a temp probe relay. Autozone sells them right on the shelf. You can adjust the temp at which the relay energizes and also connect a manual override switch or a/c on input to energize the fan. It's like $35 bucks. The probe slides in between the fins near the upper part of the radiator.