central air pump outside runs fan on furnace runs 3-4 mints then quits pump continues to run shut every thing down for 1hr it will work again for 3-4mins

 

If I understand correctly, The indoor fan shuts down after a few minutes but the outdoor section continues to run? Then we need to investigate what happens to the indoor fan. Try this first- turn the heat/off/cool switch on the thermostat to off and turn the fan switch from auto to on. What happens?? The outdoor unit should be off and does the indoor fan again run for just a few minutes and then shut off?? If so, take the cover off the front of the blower section and see if you can tell if the motor is slower than normal. Any burning kind of smell? Shut off the power off and see if the blower wheel tuns freely or if it is stiff. We need to divide into 2 troubleshooting pathways. Either something is amiss wth the motor or something is amiss with the fan relay. Some of the newer units have a fan relay that contains a little circuit board. The relay has an OFF delay. IOW- when the t-stat shuts off the cooling AND the fan switch is set to auto, the indoor fan continues to run for a couple minutes. Usually, when these relays act up, the fan just continues to run all the time but not always. These relays are very common on Trane units. I don't want to see you replace the motor only to find out that a relay is acting up. So, there are a couple ways we can approach this. Turn off the power to both the indoor and outdoor sections. Follow the wires from the fan motor back to the fan relay. See if you can figure out which ones are for the power to the motor. Try to use the wiring diagram to help out. What you want to do is make a sketch of where the wires connect to the relay, remove then from the relay and connect them together. There's two things to be careful of. First, don't get the power/motor wires on the relay mixed up with the control circuit wires. Second, furnaces usually have multiple speed motors. Normally, high speed is used for cooling and a slower speed is used is used for heat. if you energize two speeds at once, it's goodbye motor and I meanas soon as soon as power is applied. There's no second chance. If you feel comfortable with all this, bypass the fan relay so that you're only bringing on high speed. Put the cover back on the blower section, turn on the power to the indoor unit. Same thing?- the motor quits after a few minutes, then you have a bad motor or capacitor. If it keeps running, replace the relay. With this scenario, we're assuming it's not the t-stat causing the problem. It's possible but not probable.Anothe rway to go about this would be to bring power to the motor from another source like a corset to a wall outlet. You have to be very good at reading the wiring diagram in order to do this and I don't reommend it otherwise.

 

had a idea it was the capicitor so i took it off and had it checked at grainger sure enough it was bad bought anew one it fxed the problem cool thanks for your help

 

Way to go! It's always nice when the fix is simple and cheap.