99 Tahoe Mystical Problems A/C Heat Blower works when cool outside but not above 65F

[CaribbeanHigh]

I have a 99 Tahoe with some very strange electrical problems. The a/c heater blower will work intermittently. If the outside temperature is cool, 60 or less the blower will work. If the outside temp is warmer 65 or up the blower will not work. Also the front driver and passenger power door locks do the same, when it is cold they work, if the truck is setting in direct sunlight where the door heats up they no longer function, this is the front only the back locks work fine all the time. Now on to the last quirky electrical problem. The driver side front power window only operates in cold weather as well, summer and spring it will not work. When the window control button is depressed you can see a downward spike on the amp gauge and hear a rythmic clicking. Does anyone know, are these 3 things related or do I have the incredible luck of having 3 separate problems coincidentally. The A/C is a manual temp if that helps. The vehicle has never been in an accident nor has it any aftermarket anything, no electrical work has ever been performed to screw things up. This is truly driving me crazy Help

[J-Ri]

Before you start tracing the wires, get a wiring diagram and see if the two circuits have anything in common that could be failing causing neither to work. Sometimes you'll get lucky and solve a problem from a diagram. If not, you'll have to check for power at the blower motor while it's not working. Work towards the battery, checking for power at every connection. Do the same for the door locks. When you find power, try connecting a jumper wire (different from jumper cables...) from the connection with power to the next connector in line.

The window issue sounds like it might be binding somewhere, if the guage drops (you said amps, I assume you mean volts), it means the motor is trying to work.

If you find the problem, please post it. I'm very curious to know what's causing that.