FAN BLOWER FULL POWER ???

MIDNIGHT RIDER · Jul 31, 2008

According to what I can make out from this at location C/D 14 and 15 :

Picture courtesy of AGNEM, thanks.

http://image18.webshots.com/18/1/79/32/202817932OgmYDQ_fs.jpg

: The fan-blower speed is governed by the GROUND being switched through a series of resistors, RIGHT ??

Lets say I splice into the BLK wire near the blower and also the ORG wire with good heavy wire, routing both leads through TWO simultaneously switched RELAYS, such that one relay gave full power to the ORG wire, and the other relay made a direct GROUND for the BLK wire, then would I be able to switch my blower to un-hampered FULL power by merely flipping a switch; and, when the switch was OFF, still have normal anemic factory-original control of fan speed, RIGHT ???

Thanks.

typ4 · Jul 31, 2008

Yes that is exactly what I do.
I am going to put in two more relays to take the ground load off the dash wiring. It makes my gauges all funny randomly, I bet a heavy ground wire from the batt to the dash junction would help, it is just a stupid sheet metal screw around the fuse box somewhere.

4play · Jul 31, 2008

dont quite understand what you want to do, the high speed on switch is the fastest the fan will turn. the fan always has power thru orange wire, the speed resistor controls current for speed and the switch selects which resistor(s) if you want high put switch on high, if you desire auxillary control just toggle black wire to motor to a good ground. keep in mind fan motor can draw a good 30amps and spike higher momentarily

david85 · Jul 31, 2008

Please keep us posted if you are able to get more blower flow.

The Warden · Jul 31, 2008

david85 said:
Please keep us posted if you are able to get more blower flow.

+1

I would love to get extra speed from my fan, and I'm having switch/wiring/resistor problems (on "High", fan blows at high speed, but it shuts off altogether with the switch anywhere else) and I'm not sure why...I'll be following this closely...please, post back anything you find! Thanks :cool

MIDNIGHT RIDER · Jul 31, 2008

If I don't forget, I will test voltage at the motor with fan on HIGH and engine running, prior to any modifications; then, after wiring in the relays, I will check and see what I have gained.

I have had three early-80s Ford vehicles and every one of them was plagued with anemic blower performance.

I also have/had numerous Chevy/GMC trucks of various years and the blower on any of them will knock your cap off on HIGH.

If I can't wake up the blower in my Ford, I have one out of a Chevy that I intend to make fit.

Agnem · Jul 31, 2008

Take the blower motor out and make sure you don't have debrise clogging things up in there! Those resistors have been known to start fires too, so getting the debrise out is a good idea all around. I know my fan draws a good bit in the Moosestang, cause the voltmeter shows about a 4 volt difference at idle between off and high, but I bet it's clogged up. I need to take my own advice.

MIDNIGHT RIDER · Jul 31, 2008

I already cleaned a five-gallon bucket-full of **** out of the air-box; I even had the entire A/C evaporator box off and cleaned it and the evaporator with some of that foaming A/C cleaner stuff.

Cowl-vent is screened and kick-panel access holes have been cleaned out.

No concern or upkeep whatsoever has ever been given to any of the GM airways and they still easily outperform my Ford, even with cow medicine bottles, rat's-nests, snake-skins, and such clogging things up. :dunno

typ4 · Jul 31, 2008

Some crown vic blowers will fit, the motor is the same, wheel is about a half inch wider. I like mine

LCAM-01XA · Jul 31, 2008

My blower motor draws makes for a mighty good voltage drop at idle too, and it makes for some pretty strong air currents in the cab when all windows are closed. Which is pretty surprising, considering how my truck was a farm vehicle, so it didn't get quite the maintenance it should have.

4play · Aug 1, 2008

The Warden said:
+1

I would love to get extra speed from my fan, and I'm having switch/wiring/resistor problems (on "High", fan blows at high speed, but it shuts off altogether with the switch anywhere else) and I'm not sure why...I'll be following this closely...please, post back anything you find! Thanks

hey warden, you need to check and 90% sure to replace blower speed resister. it is mounted right beside the blower motor and has a 4-5 wire connector and is bolted into the a/c case. these go out alot and take all speeds but high. thats because high speed is not resisted and high speed gets full voltage.

The Warden · Aug 1, 2008

typ4 said:
Some crown vic blowers will fit, the motor is the same, wheel is about a half inch wider. I like mine

I just want to make sure I read that correctly. The wider Crown Vic wheel can fit in the F-Series housing? Wider wheel = more air = cooler cab... -Drool

me likes!!!!

4play said:
hey warden, you need to check and 90% sure to replace blower speed resister. it is mounted right beside the blower motor and has a 4-5 wire connector and is bolted into the a/c case. these go out alot and take all speeds but high. thats because high speed is not resisted and high speed gets full voltage.

Certainly beats tearing the dash apart to get the switch out...can the resister pack be sourced new? If so, where? Thanks!

f-two-fiddy · Aug 1, 2008

The resistor pack is under the hood.
2 screws and its out.
Most of the time it's just corroded terminals that cause problems.

There's not a lot that can go wrong with them.

david85 · Aug 1, 2008

f-two-fiddy said:
The resistor pack is under the hood.
2 screws and its out.
Most of the time it's just corroded terminals that cause problems.

There's not a lot that can go wrong with them.

Hey I know you. you're fon-fiddy?

BigRigTech · Aug 1, 2008

Resistor's are the issue, cheap to replace and quite common to go rusty/rotten on old Fords...If you want more flow then get a different blower motor.

FAN BLOWER FULL POWER ???

MIDNIGHT RIDER

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typ4

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4play

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david85

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The Warden

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MIDNIGHT RIDER

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Agnem

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MIDNIGHT RIDER

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typ4

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f-two-fiddy

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