Large amp draw from Taurus electric fan

[chargd72]

I upgraded my cooling system with a 26" 3 core aluminum radiator and an electric fan from a 95 Taurus.  This thing pushes some serious air.  I'm using a variable speed controller for the fan to bring the power in at 60% and increase if needed.  This is much easier on my electrical system vs straight power up at 100%.  I've already done the parallel alt wiring to handle the extra load on my upgraded 78Amp alt. 

So here's the situation.  I wired the parallel feed lines thru the ammeter like in the diagram below.  The variable speed controller(that feeds the fan) is connected directly to the battery so all my current comes from my alternator side of the ammeter.  When my fan is powered on, my ammeter shows heavy on the charge side which is expected (see below).  I'm worried about the load going thru the ammeter so I was thinking of just detaching the added parallel lines and just short them bypassing the ammeter.  This will still allow the ammeter to still read current direction, it just won't take all of the current and shouldn't over heat.  What do you guys think? 

[Cooter]

You need to put that high amp draw fan on a relay and only control the trigger with your stock electronics.

[chargd72]

You need to put that high amp draw fan on a relay and only control the trigger with hour stock electronics.

I guess I wasn't clear.  The variable speed controller is a relay.  It's temperature sensitive and is only engaged when it hits the preset temp.

[Cooter]

I guess I musta misunderstood when you had it wired through your stock wiring. If it truly were a relay, and hooked up correctly, only thing that would be on your stock electronics would be the low voltage trigger side. However, I don't think that 'variable' controller (reostat) has a relay. Relays are either on or off.

[chargd72]

I guess I musta misunderstood when you had it wired through your stock wiring. If it truly were a relay, and hooked up correctly, only thing that would be on your stock electronics would be the low voltage trigger side. However, I don't think that 'variable' controller (reostat) has a relay. Relays are either on or off.

I meant it's thermal controlled.  It's switched off if engine temp remains under 190, turns on if it goes above.  The variable speed just applies a different amount of power to the fan if needed.  Say the engine temp hits 195.  The fan will come on at 60%.  If the temp still rises to 220 the fan should be fully engaged at 100%.  

By stock wiring just meant that being connected to the battery, it is on the same connection as the charging system from the alt to battery going thru the ammeter.  Hope that makes more sense.  

[John_Kunkel]

You'd be better off to eliminate the ammeter and the firewall connectors.

http://www.madelectrical.com/electricaltech/amp-gauges.shtml