Voltage drop when fans turn on??

[tunedin302]

Hey Guys - I have an 03/04 Termi motor in my fox and notice that when the first fan speeds turn on (around 180) and also when the second speed kicks in (around 195), I notice a split-second and temporary voltage drop (from 14 down to 12 and then back to 14). Is this common on the terminators? I dont want to be in a situation where I'm WOT and the voltage drop causes a lean fuel issue. I was thinking a capacitor wired in series to the fan motor might solve this problem. Thanks

 

[03Steve]

Yep. Kinda like when the air compressor pops on in the garage. The house voltage drops a bit from the rush.

 

[VirtualSVT]

those are high amp motors so yeah your charging system is gonna take a hit when they start up.

 

[Avispa]

Your capacitor idea is good. It will cushion the temporary load shock when the fan switches on. You'll need a big electrolytic capacitor, and it needs to be wired in parallel near the fan motor, not in series.

http://www.google.com/url?sa=t&rct=...h_M2j2hrQslnTHV8kgfozkA&bvm=bv.53217764,d.aWc

 

[Tractionless1]

Billet Tech. Alternator here and I notice zero drop when the fan turns on. In cab voltage is at lowest 13.8v and high of 14.6. Across the battery 14.65v. Both readings taken when heat soaked.