When the radiator fans turn on, rpms drop
 

As usual, I may have a few problems here, but I figure Id come to the forums to see what people thing before I dig in. The car is a 2004 Mitsubishi Galant ES 2.4L

This all started this winter with my remote start not turning my car over. The starter tries for about 1.5 seconds, if the car doesnt start, it waits, and tries again 2 more times. It seems as if my car is now starting a bit harder than it has in the past.

Now on to spring. When its wet out, I can hear the belt squeak some when its idling. When I turn on the heater, the rpms drop severely as is if the car is about to die. At first I didnt put the two things together, and started some maintenance. I replaced spark plugs, needless to say that wasnt it.

So, I throw a multimeter on the battery, its still the original from the factory, maintenance free. It reads exactly 12volts. I start the car and it sits at a steady 14.5volts, so that all sounds great. While the car runs without either A/C or the heater on, its great. If I turn on the heater, as soon as the 2 fans on the back side of the radiator start up, the car drops from 800 to about 300 rpms. The voltage does not drop though. When watching the multimeter when the rpms drop, there is little to no fluctuation of voltage.

I suspect there is multiple things happening here, and if I had to guess, Id say possibly a bad auto-tensioner (the belt looks fine). Maybe bad connections somewhere like at the auxiliary fans? I thought maybe bad alternator also, but that seems to be charging just fine.

Hi BroH,
I have the same problem in my Out 2006. Once the A/C (in summer) or heater (in winter|) starts the rpm's drop. I have asked the dealer from day one and they have said it is the way it works. I have not much to say rather than you are not alone on this.

I understand that the components are putting on more draw, but this car was not like this initially. I dont see any voltage draw when this happens when I am metering it.

Since the belt kind of gets squeaky in moist weather, I may just go ahead and replace the belt. I do plan on getting into the tensioner though. I believe it lies behind the front passenger side tire. It seems possible to me that if the tensioner was bad and not tightening just a bit when the fans kick in, that might make it dog down a bit also.

yeah,
 

i had the same problem in my 94 3000gt, replaced the plug wires and it works, dont ask me how haha