Heater Temperature Issue

[Mr. Meaty]

I have a 1995 Jeep Grand Cherokee Limited and the heater temperature is acting up. I need to run the temp control at 80+ to get heat to stay on. Anywhere below, and it blows hot air for a bit and then starts to blow cool air.

Since it's getting colder, I'd like to get on this now.

Is there a temp sensor in the heater controls that I could check/replace?

Since I'm getting hot air, I assume it's not the radiator thermostat.

HAs anyone experienced this problem?

[dksob81]

If you have ATC (digital controls) which it sounds like you do. There is a Ambient Temp Sensor for the interior,if you look right above the VIC you will see some vents cut into the dash look like there maybe a little speaker, Behind this the is a tube which takes air to the temp sensor and it adjusts air temp as needed. When you have you heat on (below 80) is the A/C indicator (snowflake) illuminated, trying turning the A/C off and maybe it won't switch to cold air.

[Mr. Meaty]

Thanks, I'll check tonight for the vents. The A/C indicator comes on with the heat, but it doesn't seem to make a difference when I shut it (A/C) off.

Since I do get heat, my assumption is that there's a sensor that is not picking up the right interior temp, so you're suggestion sounds good.

I'll update if I can get it working right. Otherwise, my wife might just have to run it on HI all winter.

[Mr. Meaty]

So, I've resolved the issue. A cell phone cradle was blocking the ambient temperature sensor. Removed it and no more problems with the heat.

Thanks!