AC quits working when on High- 97 ZJ

[intothewild]

Hey guys, just wondering if you any of you had any ideas what would be causing this. I believe its an issue with the high speed relay, because I replaced it once already when I first got the Jeep now the problem is happening again. The AC works great on settings 1-3 but completely shuts off when placed on High.

After replacing the high speed relay which is conveniently located beneath the dash, it worked great for a while. When symptoms started occurring again, it would shut off on High and if you gave a nice ********** to the bottom of the dash it would come back on again. Actually anything slightly jarring the vehicle, such as shutting the door would cause it to come back on.

Unfortunately, now it's not blowing on High at all again. So has anyone else had a similar issue with this? If so what did you find? I have tried searching the internet and haven't found much info. Is there another piece in there somewhere that could be causing the relay to stay closed, and then open when it gets jarred? I don't really have the time right now to pull the dash apart and mess around with it for a while, so I'm trying to find at least some course of action to take before diving into things.

Thanks.

 

[BigAl]

I have tried searching the internet and haven't found much info.

Thanks.

Try searching "blower motor resistor" normally when they fail, the fan only works on High, but maybe you have an odd one

 

[K2ZJ]

Is it the switch? Try to hot wire it to high. I have seen several vehicles where one setting doesn't work, mostly Chrysler products.

 

[nightfoam]

Is it actually shutting off or just blowing through the defrost?