Only one heated seat active at a time

[Murban]

I have a 2003 Yukon Denali and have an interesting problem with the front heated seats. As the title states, only either the driver or the passenger seat heater can be on simultaneously. If only the driver seat heater is turned on, no issues. If only the passenger's, same thing. However, when both are turned on at the same time, they both will shut off.

For context, the heating element on the driver back had gone bad, causing the seat heater to short out instantly on the driver side. However, prior to replacing the heater, there were no issues with the passenger heated seat. However, since I have changed the driver heating element, this new issue has arose. Could this be a loose connection somewhere under the seat? Or has another element in the circuit gone bad potentially?

 

[Macs05z]

I am having the exact same issue with my 05' Tahoe. When I turn on either side seat heater it goes out when I or my wife turn on the other seat heater. I have replaced my drivers side heaters, due to short, but I'm pretty sure that they both worked after the repair. I can't find anything about it anywhere. This is the first forum post that I have seen with this issue.

 

[Murban]

So in my case I was having both of the front seats short out when trying to turn the heater on. After some examination I found that the driver side back heater went bad. Replaced that and had no issues until this started not too long after. What I am thinking is that the bottom part of the heater is also going bad. Going to try and test that and see if it is the issue.

I am assuming that you replaced both the seat and back heating element on the driver's side? If so, I would say that likely one of your passenger side heating elements is going bad.