Not throwing heat

[BeeKool]

My 95 Dakota is up to capacity on coolant, has a new thermostat, the blower works fine, and the temp gauge says it's up to temp.
I've flushed the system and still no heat.
Before I tear the dash out and lose all of my A/C 134a pressure to replace the heater core is there any thing I'm overlooking?

 

[HALIFAXHOPS]

Heater control valve open?

 

[BeeKool]

Heater control valve open?

How does one test this? It will throw out a/c if I ask it to.

 

[HALIFAXHOPS]

How does one test this? It will throw out a/c if I ask it to.

Look at the heater hoses it is usually mounted there on most cars. Prob has a vac line to it. If the hose is warm up to it and cold after it is bad. You might be able to open it manually somehow. Worth a try at least.

 

[silversedan]

did you flush the heater core by itself, meaning take hoses off and use water pressure from a hose , alternate back an forth on the tubes till it comes out clean.

 

[HALIFAXHOPS]

Good point also seems like they need a back flushing. I would trouble shoot it first and see where he ends up. Control valve, heater control vacuum to the valve then a back flush. Has to be one of those. Not sure if it has a blend door, not familiar with them.

 

[cudajunction]

Look up blend air door for your application and see if they break most of them do.

 

[super-bee_ski]

Or?
Thermostat stuck open?

 

[BeeKool]

did you flush the heater core by itself, meaning take hoses off and use water pressure from a hose , alternate back an forth on the tubes till it comes out clean.

No I didn't. I could drain and save the coolant. Refill with H2O and remove heater hoses from firewall and try power washer (on low) on them.

 

[BeeKool]

Or?
Thermostat stuck open?

Condsidered that. Temp gauge says trucks running at proper temp though

 

[khryslerkid]

I'd try the temp control, blend door. The full size trucks are known to have this problem when the heat hasn't been used for awhile, like through the summer.

 

[HALIFAXHOPS]

No I didn't. I could drain and save the coolant. Refill with H2O and remove heater hoses from firewall and try power washer (on low) on them.

To much pressure just use a garden hose.

 

[Cranky]

The T-stat on my 95 is stuck open and I still get heat and from what I understand, the heater core is constant flow. They've been using that system for awhile now because it keeps the core cleaner and open plus once the engine is up to temp, you don't have to wait for the heater core to heat up or cool down when you want to make an adjustment. Look at the blend door and make sure the vac lines are still hooked up and operating the canister. I know there's a canister on the far right side under the dash. Been too long since I've had to mess with mine. I know all the foam seals are gone on mine and I can feel cold air coming in through the firewall in the winter time plus mine will hardly put air up on the windshield anymore.....after things, these things are not spring chickens anymore.

 

[BeeKool]

To much pressure just use a garden hose.

I've been told take it to a car wash and do it. Sounds like a pain. I will tray it your way.

The T-stat on my 95 is stuck open and I still get heat and from what I understand, the heater core is constant flow. They've been using that system for awhile now because it keeps the core cleaner and open plus once the engine is up to temp, you don't have to wait for the heater core to heat up or cool down when you want to make an adjustment. Look at the blend door and make sure the vac lines are still hooked up and operating the canister. I know there's a canister on the far right side under the dash. Been too long since I've had to mess with mine. I know all the foam seals are gone on mine and I can feel cold air coming in through the firewall in the winter time plus mine will hardly put air up on the windshield anymore.....after things, these things are not spring chickens anymore.

These things may not be spring chickens, but they are tough as hell. Pound for pound the toughest truck ever made and every bit as reliable as the S&W .357 that fits perfectly between the split bench seat. I have several for parts so I may just have to do some parts robbing if I run into complications. It is a pain to remove the dash. Mainly because you lose all your refrigerant. I will just need to recharge the system if it comes to it

 

[HALIFAXHOPS]

Do all the above before pulling the box out can be something simple.

 

[HALIFAXHOPS]

Did you ever see if both heater hoses heat up?

 

[Cranky]

I've been told take it to a car wash and do it. Sounds like a pain. I will tray it your way.

These things may not be spring chickens, but they are tough as hell. Pound for pound the toughest truck ever made and every bit as reliable as the S&W .357 that fits perfectly between the split bench seat. I have several for parts so I may just have to do some parts robbing if I run into complications. It is a pain to remove the dash. Mainly because you lose all your refrigerant. I will just need to recharge the system if it comes to it

I've had many Dakotas and have had this one since 98. Dad bought it new and I got it when he passed on. Yeah, they are like old Dodge Darts. They just keep on running and running. They are pretty easy to work on too. I parted on several years ago and it surprised me how easy it came apart. And nothing on mine works like it should but everything still works good enough lol. Can't complain as it's been an outside dog all of it's life and has been rode hard and put up wet most of it's life too. If the core isn't leaking, you're usually in the good. Do you smell coolant in the cab? Most cores that are clogged with gunk can be cleaned out without pulling them and I would start with the water hose too. Might try some radiator flush if you still are not getting any flow but if you've done any kind of maintenance to the cooling system and used antifreeze, I'm betting it's not clogged up. Mine has been neglected many many years. Kinda afraid to do a flush now since it'll probably flush out all the junk and start leaking lol

 

[BeeKool]

Same here. This old girl has been an outside dog as well. I've eaten, slept, done everything but **** in this truck.
I will try everything else before tearing into the dash. Sucks because I will have to clean the old girl out. Lol lots of soda cans and God knows what else on the floor.
Most of my trucks all have good bodies. I'm (someday) goin to take one of the 4w4 chassis and rebuild one of the 318s to about 300hp. And make myself one badass little truck.
The subject we are discussing is a 3.9 liter 4x4 with 180k but is very reliable.

 

[Cranky]

Mine is only showing 97k....sure doesn't sound right though. Been meaning to check it but that's been years of meaning to. Mine is a 3.9 reg cab 2wd and needs a 3.90 gear badly. I put some real short tires on the back recently and it really made a difference and have been thinking of throwing an 8 3/4 under it. I just happen to have a 4.88 chunk laying around I bought a new 92 with the 318 and 3.90 limited slip and it was a fun truck and wish I kept that one.

 

[Mike67]

I'm not sure on Dakotas but my 02 ram has a blend door and constant flow like Cranky said. The spline gear on the door is probably broken and has to be replaced.
I think its a $10 part. Check out HeaterTreater for the repair kit...
https://heatertreater.net/?SID=lhq5eu0fbmv4612o09i4024t42