overheats in warm weather only

OK guys, my 95 SL1 has had this problem for the last 2-3 summers! Only in warm weather will the temp guage go up to halfway or higher (ususally runs about 1/4). The thing that baffles everyone I talk to is that in order to get the temp to drop, I must turn on the A/C! When I do this, it will drop within a couple minutes!! :confused: This is backwards from everything I've ever heard about turning heat on to dissipate the heat from the motor(which doesn't work, by the way). Last summer was terrible due to my belt squeaking every time I turned on A/C, but I've solved that by replacing the tensioner, alternator, and belt. My plan is to get a coolant flush and thermostat, but I don't want to play hit or miss and spend my money and still have the problem. I have no income and am living on student loan checks, so can't afford to do something that won't work. I also feel a noticable loss of power when I turn on the A/C, could this be related or something else? My SES light came on last week while at taco bell drive thru, but temp was not elevated at the time, and light has not been on since. When scanned, no codes were shown. Warning light on dash does not come on when it overheats either. I have no problems with this in the winter. Any advice b4 spending my $$ would be appreciated...THX!! :)

Check your fuses (cool fan especially),

Is your fan coming on when your engine is overheating, at most 3/4 of the way up? If you don't know, you can jumper fused wires (30A) to the fan side of the harness, from the battery, if the fan doesn't come on the fan motor needs to be replaced. If it does, but not when your car is overheating, then you need to replace the cool fan relay.

Before you replace the thermostat, if your engine is hot and the upper radiator hose isn't, then replace the thermostat because it is stuck closed, and not allowing coolant to circulate to the radiator

Check the condition of the coolant fluid (should be "transparent" not rust colored, and no "grime")

Check the drivebelt as related to the waterpump, and for proper tension

Draining, flushing, and refilling the cooling system may not fix the problem, but will definitly help the problem,

when you do this, get the cap pressure tested at a local shop

sound to me the problem isn't that you are over heating, its that in cold weather it won't get up to temp. the normal position of the temp gauge is a hair below the 1/2 mark. both the thermostat and ECT may be at fault. i would replace the thermostat and coolant as preventive mantaince, and replace the ECT if it has never been replaced before. the cooling fan comes on automaticly when the A/C is turned on to reduce the extrime amount of heat the A/C system creates, when the A/C is first turned on it hasn't built pressure/heat yet so the only thing the fan is doing is cooling the engine for the frist few minutes. turning the heat on full blast does cool the engine too, but its not as appairent (and in the meantime i'm sweating like a pig!)

The coolant temp sensor does weird things when it is ready to fail. :screwy: The thing that baffles everyone I talk to is that in order to get the temp to drop, I must turn on the A/C! When I do this, it will drop within a couple minutes!!

If you can find the all brass one they are best. Dealer, saturnparts.net, or .com.