Changed my water pump and now I have no or little heat???? 99 ram 4x4 5.9

 

your heater core is plugged take the lines off and run water in one line and out the other

 

are both heater hoses getting hot ?
have a thermostat in ?
temp gauge on dash showing normal ?
radiator and radiator hoses getting hot ?

if all hoses except the return heater hose are getting hot, then you might have an air pocket in the heater core ? if so (don't get burned) try taking the return hose loose and squirting it full of water w/ the water hose. with engine cold it might even be a good idea to take both heater hoses loose and back flush it good. nasty stuff usually comes out. also proves its not stopped up.

if both heater hoses are getting hot, and you're still getting no warm air, then the air control dampers may not be working right.

 

i have the same prob, but i havent changed the pump yet.... i can feel the temp door moving in the cabin, have changed the t-stat twice in 2 weeks, flushed both sides of the core and still only have mild heat, all controlls work(like the where air is going), please help sooon i live in alaska and its getting cold alreaddy

 

I had the same problem last year replaced everything all it was was the system was air bound and wasnt circulating properly

 

I had the same problem last year afterreplacing my water pump. It turns out I was a little to generous with coating thewater pumpgasket with RTV. Some of it ended up in my heater core blocking the flow of water. I reversed flushed just the heater core and a long piece of RTV came out. Problem solved.

 

well found out the prob...the heater core is partially blocked...not internally but the outside of the fins....leaves, cigarette butts, hair, crud...fun stuff to clean out...so i removed the blower motor and acessed it through there, used a flashlight and mirror to see and a shop vac to remove, next step is to find a way to remove whats left inbetween the fins, to get back to normal conditions, now its just better and do-able.. not quite healthy but hot so bad... so to end this ramble thx to all who read and helped...

 

living in alaska and no heat.... this is not good. if you can find a way to make/bend an air line to get on the back side of the core you might can blow it out with compressed air. good luck.

 

yup thats my next course of action...thx again ill keep you informed