B Series has no heat!

[vinnie07]

I am fixing a heating problem in a 96 Mazda B Series pickup. 3.0L V6. The problem is the temp gauge on the dash will get into the normal range, but no heat will come out of the vents when I'm in the truck. Today, I replaced the thermostat (simple place to start, right? ) and refilled the radiator with fresh coolant. Unfortunately that didn't fix it, it's still cold in the truck. I need some direction for what I can look into next. I'm thinking a radiator flush is needed and the heater core may be clogged. I would of flushed it today, but it's freezing where I live. Will a radiator flush clear a clogged heater core or am I looking at getting a new one? Other ideas? Any suggestions would be appreciated. Thanks!

 

[rangerman84]

my friend is havin the same problem with his 98 b3000 i aint been able to track it down but if i do ill let you know

 

[BlackBII]

You have two heater hoses going into your firewall on the passenger side.

Are they both hot to the touch when the temp gauge shows the truck is warm?

 

[v8318cid]

Flushing the radiator may or may not help. Depends on how you go about flushing. Installing a T in your heater lines will generally yeild better results than just removing radiator hoses for example. Considering the size of the passages in the average heater core, flushing may not be possible. Like mentioned above, start by checking your lines going into the firewall. If both sides are hot, your heater core is probably good. If one is noticibly cooler than the other, your heater core is probably stopped up.

 

[modelageek]

I am fixing a heating problem in a 96 Mazda B Series pickup. 3.0L V6. The problem is the temp gauge on the dash will get into the normal range, but no heat will come out of the vents when I'm in the truck. Today, I replaced the thermostat (simple place to start, right? ) and refilled the radiator with fresh coolant. Unfortunately that didn't fix it, it's still cold in the truck. I need some direction for what I can look into next. I'm thinking a radiator flush is needed and the heater core may be clogged. I would of flushed it today, but it's freezing where I live. Will a radiator flush clear a clogged heater core or am I looking at getting a new one? Other ideas? Any suggestions would be appreciated. Thanks!

did you get it solved?

 

[hondaxr650]

Check to see if both heater hoses get hot. If they do, You probably have the dreaded broken blend air door in the heater box. The shaft at the top of the door cracks and falls apart where the blend motor goes into it. Replacing it requires removing the dash. Been there, done that on my own 97 and several others..

 

[modelageek]

my friend is havin the same problem with his 98 b3000 i aint been able to track it down but if i do ill let you know

did you get it fixed?

 

[vinnie07]

Thanks for the replies! I did feel the heater hoses and one was hot the other was cold. I felt them after I went for a drive around the block and the temp was in the normal range. Upper radiator hose was hot. I'm assuming the hot one was the supply and the other was the return?

 

[88_Eddie]

i had this problem in my bronco 2, ended up being the heater core. it sat for a few months when i was in college, i replaced everything, didnt fix it, took it to a buddies shop and flushed it, worked great after that

 

[modelageek]

Thanks for the replies! I did feel the heater hoses and one was hot the other was cold. I felt them after I went for a drive around the block and the temp was in the normal range. Upper radiator hose was hot. I'm assuming the hot one was the supply and the other was the return?

did you feel the heater hoses at the point they go into the firewall? does the truck have AC?

 

[vinnie07]

did you feel the heater hoses at the point they go into the firewall? does the truck have AC?

Yes, I felt the two heater hoses that go into the firewall. One was hot the other was cold. And the truck does have A/C.

 

[BlackBII]

One hose was hot, the other cold.

This means the coolant isn't circulating through the heater core. I bet it's plugged up. I would pull it out and see if you can run water through it.

 

[modelageek]

Vinnie07.disconnect both hoses at the heater core Take a garden house and connect to the line of the heater core that was Cold. You can use a foot of heater hose and a hose fitting. then take a longer hose and connect it to the other side of the core and hang it over the edge of the truck. Turn the hose on and pray crap comes Out. Make sure that the return hose(the cold one) is not clogged!

 

[modelageek]

One hose was hot, the other cold.

This means the coolant isn't circulating through the heater core. I bet it's plugged up. I would pull it out and see if you can run water through it.

on his Model you need to pull the dash to change the core.....He should backflush like I suggested and hope a bunch of crap comes out

 

[modelageek]

Yes, I felt the two heater hoses that go into the firewall. One was hot the other was cold. And the truck does have A/C.

since you have A/C that means you have a heater control valve in the heater hose supply line to the core. but since the heater hose is hot at the firewall the valve is working........I put as much stuff in my signature so that it is easier to help DX......if you had listed AC in your signature then I would have known I add whatever I can think of, transmission, Motor, mileage, location, if you have a k & N filter, etc etc,,............................in this case it would not have matter because you are working on a different truck then your own.......