it is in an 82 1/2 ton with air. has a vacuum shut off valve to shut water off when air is on. i understand if air is off water does go through heater core. it runs cold if the valve is closed or open. i cant believe a hunk of cast iron is beating me. look guys i do appreciate all suggestions. i aint young and dumb just old and senile

 

I feel you are trying to fix something that isn't broken and will never have any luck with it.

 

u may be rite and i thank u for the replies. either i win or lose. i will let u know either way. just a hard headed old man. there has to be a reason for this that i havent found.

 

Old man here also.
You'll have to admit that it's a heck of a lot better than not being able to find the cause of an engine that's running too hot.

 

u are so rite. in the 40 + years i have been in the business this is the first one that has run cold. if it wasnt for my mother on cold mornings i wouldnt think about warming it up. now though it has become a challenge.

 

I live where it's much colder than you and no heater certainly becomes an issue.
I use a winter front and run with the fan removed for about seven months out of the year.
Using the recirc position on the heater control helps the most though.