Our 2005 U320 dash heat delivers hot air and sometimes delivers cool air with the heater turned to its highest setting. Any ideas?
The vacuum system that operates the blend doors is acting up. Could be the vacuum pump, the control head, a hose leak, vacuum motor leak. etc. are some of the usual suspects. Start with the vacuum pump to see if it is working. Do a search for the topic as there have been many threads on this issue.
Good luck
I do not have heat on the dash. Never needed but I think there is no water going through the system. Is there a valve somewhere that will allow the water to go to the dash heater? Tks DAN
Dan, Two valves, one is in the line to the motoraid system, probably right by the water heater. Closed it directs all cooant to the dash. Open it allows coolant to circulate to water heater.
Second is "H" Valve near dash heater core, it allows flow of coolant to heater core to vary. May be vacuum operated or cable operated. Cable could be off or jammed, or vacuum not reaching it.
Gary B
See, Gary. I told you we need you to stay active on Foforum! The knowledge you can provide is invaluable! Stay active. We need you.
Norm/nitehawk