Engine How many amps does a Mercury Villager fan pull?

[boostfrk]

I picked up one of these in the JY a few months back and am hoping to install after the New Year.

Anyone know how many amps these pull on the high speed? I'm planning to pick up a Flex-a-lite VSC from Summit but want to make sure I get one that can handle the fan.

 

[gearheadboy]

Wire it up to a battery and put a properly fused meter in line and find out. That's the best way.

 

[boostfrk]

Wire it up to a battery and put a properly fused meter in line and find out. That's the best way.

This is my 'Plan B', but was hoping someone out there had the knowledge.

 

[HISSIN50]

Unless you're holding out on us, you'll probably need a shunt

 

[gearheadboy]

Unless you're holding out on us, you'll probably need a shunt

Shunt is that like a penny behind the fuse?

 

[HISSIN50]

Most DIYers don't have an ammeter able to accurately measure current in the 100 amp range.

 

[boostfrk]

Most DIYers don't have an ammeter able to accurately measure current in the 100 amp range.

Raises hand. This is me. Plan 'B' not only involves measuring it with an ammeter but also involves purchasing an ammeter.

 

[Boydster]

You could measure the ohms of the fan motor, divide by 14.5 (max volts) and that will get you close for running amps.

14.5 volts divided by, say, .145 ohms = 100 amps.
.100 ohms = 145 amps.
.253 ohms = 57.31 amps.

 

[MikeH686]

Good reference of ohms law

 

[boostfrk]

You could measure the ohms of the fan motor, divide by 14.5 (max volts) and that will get you close for running amps.

14.5 volts divided by, say, .145 ohms = 100 amps.
.100 ohms = 145 amps.
.253 ohms = 57.31 amps.

Now you're thinking.! Thanks.

 

[7991LXnSHO]

The impedence may not be the same as the resistance. But it is a good place to start. The newest Street Rodder magazine had an electronics article. The article's guide is 1 amp per inch of fan with 2 TIMES THE amps for start up. Add a little extra for safety in your relay. (edited for stupid phhone errors!)

 

[gearheadboy]

Thats pretty close to what I've heard they pull. Does that count the spike when it first powers up?

 

[7991LXnSHO]

I'll let you read and decide the author's intent - I think yes, the article does cover your spike with 2x the amps.
Pg 92, top of second column of the March 2013 Street Rodder magazine. (It has a red '32 with a supercharged W motor on the cover)
" ELECTRIC FANS
On average, an electric fan will require 1 amp per inch of overall diameter to operate at normal speed. For instance a 12-inch fan will require 12 amps to operate but also note that twice the amperage is required duing initial start up. Be sure the circuit protection can handle the start-up load as well as the fan relay."