Heater question

I have a 1995 Winnebago MH with a Ford 7.5L gas engine. traveling in temperatures around 35 degrees the heater was not putting out enough heat - not even real hot. and the faster I went the cooler the heat and the engine temp gauge was. sounds strange I know but is this a thermostat issue or heater core or both? ps: the a/c in summer does not cool either

 I would likely replace the thermostat.  How long has it been since you replaced the coolant?  I would also look for a possible vacuum problem. Is there any history on this vehicle?  How many miles, what kind of care, etc.

I don’t know the history - I just purchased the vehicle this summer. the coolant was full and looked clean. 55600 miles and appears to be well maintained

Have the cooling system flushed and the thermostat replaced. That will probably solve your heater issues. The AC problem is probably caused be a leak. Take the vehicle to an AC shop and let them fix it.

The heat and AC systems are separate. A problem with one does not necessarily relate to a problem with the other.

thanks for your help - I will git r done