Radiator Fans current draw messing with Megasquirt - Alfa Romeo Bulletin Board & Forums
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post #1 of 3 (permalink) Old 10-12-2014, 05:27 AM Thread Starter
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Radiator Fans current draw messing with Megasquirt

i have Mesgasquirt running on my Alfetta quite well.
However when the coolant heats up and the radiator fans switch on, the current drawn causes the engine to loose revs and go lean while the fans are on.
Everything goes back to normal when the fans switch off.

I had the alternator re-wired from 60+ to 85 amps but it made no difference.

The Auto Electrician said the wiring was all ok and that he felt the alternator wasn't turning fast enough at idle, so I put the smallest Alternator pulley i could get, but still no good.

I don't know how much current the two fans draw, but I was wondering if anyone else has similar issues and what can be done to rectify it.


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post #2 of 3 (permalink) Old 10-13-2014, 04:08 AM
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Well, as per what I suggested on your other thread, fit a modern alternator.

Failing that, set up some sort of idle speed increase when the fan switches on and the TPS says the throttle is closed.
Does the MS have an air con input? Send a radiator fan on signal to the A/C input and set the idle speed high enough so the voltage is high enough.

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post #3 of 3 (permalink) Old 10-13-2014, 06:44 AM Thread Starter
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are you referring to the post I did October last year?' I totally forgot about it. And i cant believe I still haven't sorted out the problem.
Anyway I believe MS does have a way of increasing Revs when the Air Con kicks in, I'll look into it and see how I go.
Meanwhile I may be able to get hold of a Twinspark Alternator from a friend. If i can get that I'll give it a try first.
thinks for the advice,

Last edited by sammbo; 10-13-2014 at 06:59 AM.
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