No heat on drivers side/ Air blows on and off when started

So I recently bought a 2011 Jeep grand Cherokee 70th anniversary with 100k. The first thing I noticed was after I would start up the Jeep the air would blow full blast for one minute then it would stop for 6 seconds then automatically come back on full blast for one minute, etc. It does that on and off about four times for a total of 5 minutes. Then works fine till the next time the car is turned off/on. The next problem I noticed is there is no heat on the drivers side vents no matter what I set the temperature at it only comes out as outside temp. The knob used to go from feet to head to defrost works fine, just no heat. Passenger side works perfect. Any help would be greatly appreciated

 

This could be 1 of 2 things.

1. A/C Control switch is faulty and it's only working on a few settings and not all. Chances are that if you were to pull it out and check the connector. If both the connector and Control switch looks burnt, both connector and switch MUST be replaced.

2. The heater Control vent valve ended up failing making it not properly channel through the correct setting.

Personal experience: flush your heater core. Since it's a 2011, it would be wise and wouldn't hurt. Gunk does build up over time and can seize your heater core valve giving you only 1 setting. Just so God for bid after you replaced either one, and then your heat stops working. Now you need take everything apart again and it's just a hassle.

 

Ok thanks for the suggestions. Do you think both issues are related, the no heat on dr side and the blower on/off??

 

Yes! The control switch opens/closes the vents would be the issue at hand.

 

Ok thank you for the suggestions. I’ll post back with updates

 

I’m guessing you have a vacuum leak I had the same issue mine was a vacuum line ran underneath the battery.