Electric fan and charging

[88GThatchback]

I want to get an electric fan. I have the stock alternator with the stock pullies. Will I have charging problems if I get a fan? Has anyone used a 16" Zergo fan off ebay? I don't like the looks of the blackmagic fan. Is 16" the right size for a stock radiator?

Thanks,
Clay G.

 

[Idwitheld-1`]

you WILL have charging problems.

My PA performance Alt was a week late and I had to drive around for a week in low gear (AOD). Othewise, the battery would not charge.

 

[Michael Yount]

And when you put the fan on, here's the way to control it. This device is head and shoulders better than anything else available. Just put one on mine - couldn't be happier. http://www.dccontrol.com/

 

[jrichker]

You will need a bigger alternator, like a 3G. Here's websites with pictures of the 3G ( 94 Mustang and later 130 amp alt) installation procedure...

See http://www.geocities.com/smithmonte/Auto/3G_130A_Alternator_Upgrade.htm - all the tech data you could ever want to know
OR
http://www.fordmuscle.com/archives/2001/03/paperformance/index2.shtml
OR
http://www.mustangcentral.net/tech/alternator.html - excellent pictures of installation

For the right way to do the wiring. Some people will tell you that you can skip the wiring upgrade, but it will catch up with you sooner or later. A fire in the wiring harness is ugly and expensive.

 

[PuppyDawg]

Relay?

Would it remedy the "problem" if relays were thrown into the equation?....like a dpst or a spdt relay?...i notice a big current draw when my electric fan comes on and it messes everything up (for a while) and then it gets better later.....probably the cause of my "surging on a cold start" issue.....

 

[jrichker]

Would it remedy the "problem" if relays were thrown into the equation?....like a dpst or a spdt relay?...i notice a big current draw when my electric fan comes on and it messes everything up (for a while) and then it gets better later.....probably the cause of my "surging on a cold start" issue.....

A relay is nothing more than another way to close a switch. They don't make more current or ease the starting current surge. The DCControl fan controller would at least ease the starting surge, but you are still left with an electrical system that is underpowered when everything is on.

Figure this:
Ignition system & computer = 12 amps
Fuel pump = 12 amps
Exterior lights = 15 amps
Fan (heater or A/C) = 15 amps (can run between 5-25 amps depending on setting)
Radio & instruments = 10 amps
Wipers = 10 amps

That's grand total of 74 amps from a 65 amp alternator. Talk about overdrawn at the bank!

 

[Michael Yount]

Remember - the alternator's rating is a 'nominal' or average rating. The 65A alternator, if pulled on hard enough to require it, is capable of putting out currents over a curve of output that varies from about 15A at idle to about 66 amps up around 3 or 4k rpm. So the overdraw my buddy jrichker refers to is even worse than imagined in stop and go conditions with the stock alternator (go to www.pa-performance.com for more info on rpm/potential output). You'll need at least the 95A alternator, but the current controller is highly recommended. Not only does it do away with the start up spike, it only spins the fans as fast as need be to cool things down, so it minimizes current draw on the system at all times.

 

[PuppyDawg]

That's grand total of 74 amps from a 65 amp alternator. Talk about overdrawn at the bank! [/QUOTE]

ouch......thanks for the info bud *sighs* i guess it's time for some rewiring on the stock alternator then.....i'll print out your links and put them into good use.....my mechanic was trying to talk me into going back into the stock/clutch fan....but i have confidence in this electric fan upgrade.....but it was installed before i purchased it from a kid that (obviously) didn't know what he was doing....