Lately my interior heater is only working on the dash. No matter where I position it it only stays there. I have heard that it could be a vacuum line but I am having a hard time locating this line. Does anyone have any ideas or has it happened to someone else. Much Thanks
My Betsy has 895,000 kilometers on her and I am hoping she will hit a million Kilometers.

 

Check the vacumm pump when you first turn the truck on, before you start it you should hear it running under the hood on the passanger side.

Then check both the lines that run down to the front hubs, you will see them right next too the brake lines.

 

That's exactly what it was with mine......replaced both of my lines to the hubs a few years back for the same symtoms

 

Thanks for all your help. I replaced the vacuum pump @ $182.00 Cnd and all is working well.