Quote:
Originally Posted by divineinc
On the way into work this morning I noticed the heater would blow warm than cold than hot and all over again. It seemed like RPM would affect it but not 100% sure.
Truck was fully warmed up and did not overheat.......
Any ideas/advice?
|
Near perfect description of heater behavior when there is air in the system. Despite the leak, you can verify this by......properly purging and filling the cooling system. This will answer the question unless that leak "isn't so small", and worse yet, if the cooling system replaces lost coolant with air every time the engine cools down. This could happen because drawing air through that leak might be easier than drawing coolant from the burp tank, and thus, air is introduced into the cooling system and...."the problem" of wandering heater temp output. Because of this, that leak really needs to be fixed to eliminate a potential cause of the prob.
Quote:
Originally Posted by divineinc
....I have a new thermostat and housing but the rubber hose coming off the housing (about 8" long with that stupid 90 degree bend) is in need of replacing and has a small leak. I have a replacement but I couldn't get it on within the 30 minutes of trying and just used the old one........
Any ideas/advice?
|
Recommendation based on experience......that hose with the 90* bend....it needs to be Motorcraft thanks to the 90* bend being pretty much a right angle rather than having a bend radius (look how tight it fits into that space). Good luck with the non-Motorcraft hoses (Dayco, for example), been there tried that.
Quote:
Originally Posted by divineinc
.......The controls are working for direction (defrost/face/toes) but the fan speed has always been on or off. Works on High but shuts off on all other speeds. That doesn't bother me, I'm used to it.
Any ideas/advice?
|
The most common cause for this is the resistor pack has failed. It's located in the airstream in and on the evap case, simple to replace and inexpensive. Removal of the part can confirm failure, as will usage of a DMM and with the part in place (faster).