Cooling Fan drawing too much power.

[vivamolina]

I had an 85w fan that wasn't cooling the engine enough—it would overheat on idle. I just replaced it with a 120w fan that is doing a much better job at cooling the engine, but I noticed it draws quite a bit from the engine when it comes on. When installing this latest fan, I wired it straight to the starter/alternator, as opposed to the original circuit. Is that why my engine dips when it comes on? any thoughts?

thank you!

[Nut124]

I would inspect the cooling system for other problems. A bigger fan should not be necessary.

120W is way more than most alternators are rates for.

How long have you had the car? Did it ever work properly?

[redcars]

120w is only 8.5 amp and should not slow your engine down. That said a property maintained cooling system will not need a larger fan. I have had my 124 in 100 plus degree stop and go traffic with no problem cooling the car, only the driver.

[Nut124]

120w is only 8.5 amp and should not slow your engine down. That said a property maintained cooling system will not need a larger fan. I have had my 124 in 100 plus degree stop and go traffic with no problem cooling the car, only the driver.

You are correct about the fan, alternator amps. I was confusing Watts and amps.

[TX82FIAT]

Captain obvious for a minute. When the extra load of 8.5 amps is put on the electrical system the alternator is forced to increase its output which temporarily puts extra burden on the engine to compensate. 8.5 amps should not have that drastic of an effect. You mentioned your fan is wired directly to the starter solenoid. Does you fan stay on after the car is turned off following a running hot situation. I only ask because it is "possible" a hot car will stay hot and warp a head. I would suspect a resistance issue at the ground or someplace else in the circuit making it harder to push current through that circuit creating a power draw. Could even be the temp switch itself. The comments above are on point. A properly functioning cooling system should not need a larger fan. Again, one could argue a larger fan will see/saw the temperatures and is not the best thing for an older car. I have found the car runs best right at the left edge of the 0 in 190.

[spider2081]

I would expect the engine RPM to drop noticeably at idle when the coolant fan comes on. Possible even the battery warning light could light.
The fans load is similar to that of the head lights. Does your engine RPM drop when you turn on your head lights?