95 Dodge Ram 1500 - no heat

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woodworker4421

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*new to this group*

Bought a 95 dodge ram 1500 with a 5.9. I don't have any heat. Umm, anti freeze level is full. Both heater hoses are hot. Thermostat is opening and closing. Blend door seams to be working. Flushed heater cord today - I do not hear any gurgling from the heater core under the dash when driving. I when I turn the knob from heat to air conditioner - air conditioner side is cold. Heat side is warm not hot. That would tell me the blend door is working. With both heater hoses getting warm tells me the heater core is flowing. The only thing that I see that the heater is not doing is when I go to defrost to floor - it stays in the defrost. Blower works in all speeds. Drove it tonight outside temp was 20 degree. Thermostat opened twice- but with little heat at defrost.



What can I try now? I don't care about the A.C.


As far as it blowing in defrost that is fine with me. I rarely switch it.


**What do I do from here?**
 

Okiespaniel

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You have either a bad vacuum check valve, cracked or broken vacuum line to the defrost door or a possible blend door issue.

I think if you still google "Dodge Ram wild vents" or "Dodge Ram vent issues" there's a plethora of information available.
 
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woodworker4421

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with a plugged check valve or cracked line would that cause a no heat problem. I think the blend door is working correct
 

Mike Flea

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Did you buy the truck used? Flush the cooling system. There's a possibility the previous owner mixed red coolant with green, the two mixed together causes the coolant to gel, clogging the tubes and inhibiting flow.
 

Okiespaniel

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Ok...

First off you have heat, that's why both heather hoses are hot. The heater core isn't the issue. These trucks don't use a shutoff valve for coolant. I guess you know that so we're good.

Secondly, you have a series of vacuum and electrical solenoid/ motors that open and close doors to direct that heat. The vacuum controlled doors have a check valve which keeps them open so they don't open and close with engine vacuum. The electrical ones can fail or get jammed if a hinge pin breaks.

If your heater hoses are hot and you have no heat you have a door issue. That is also why the system defaults to defrost. The feds require it.

Now you may be able to get your fingers up behind or beside the HVAC unit and find a broken hose, or a nipple missing one. The check valves (at least on my truck) are on the vacuum junction on the passenger side near the firewall in the engine compartment.

This is why I suggested to the OP to GOOGLE the information. Different years of Rams, while similar in design have had slight changes in the HVAC unit and the vacuum configuration. Now there may be someone who'll chime in with the solution, but this forum isn't as crowded as it was years ago. You could also run a forum search here as well. "Wild vents" or "vents defaulting to defrost" was not uncommon in these trucks but I've been blessed by not having this issue.
 
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woodworker4421

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I did flush heater core both ways.i did see the blend door cable and lever moving. when I put it to air the air does come out cold. when I go back too heat it does get a little warmer but not a whole lot warmer. do you ththen to the other doors. ink that there is another door not opening or closing?. I really don't care if it stays at defrost on all my other cars I just shut the fan off never move those to floor they just stay at defrost. it is cold now where I live so I will wait until warmer weather so I don't break those vacuum lines. the vacuum line from engines goes to the back of the switch correct. I know on my impalas I have those electric control doors I have replaced those before . I don't think the 95 ram use them just figure out the vacuum and go from there
 

Okiespaniel

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Well I googled Dodge Ram defrost only...

Start here... And keep looking and checking vacuum hoses and the like until you get it fixed.
It's only difficult if you make it. Push through and find it.

Good luck
 
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woodworker4421

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I understand the vacuum leak not causing the doors to the floor or vents too open.I still should have hot air coming from the defrost vents? run the truck for about 30 minutes and the windshield is still frosted up.could the heater core be semi block. how many doors does the heater box have to operate? I never really got to monkey around a vacuum leak before.so when you start looking for a vac leak where do you start?just pull a vac line off and see if I have vac and then move to the next connection?where all does the vac lines run? heater assy brake booster pcv valve . I read a lot of people having a vac line under the battery box going bad where does that line run?
 
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woodworker4421

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I understand the vacuum leak not causing the doors to the floor or vents too open.I still should have hot air coming from the defrost vents? run the truck for about 30 minutes and the windshield is still frosted up.could the heater core be semi block. how many doors does the heater box have to operate? I never really got to monkey around a vacuum leak before.so when you start looking for a vac leak where do you start?just pull a vac line off and see if I have vac and then move to the next connection?where all does the vac lines run? heater assy brake booster pcv valve . I read a lot of people having a vac line under the battery box going bad where does that vac line go
 

Mop

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Have you checked the Actuator door? The factory plastic piece cracks, and doesn't allow the door to fully turn from cold to hot, and vice versa. My '99 Sport had this problem.
I bought this http://heatertreater.net/dodge-ram-95-02 and took the actuator motor down from the bottom of the dash. It now works fine.
It's very close to the tranny hump, so get a 90 degree screwdriver, pull back the carpet, make a small slit in the floor so it'll fit into the screws, and carefully remove the motor. Replace the piece. Carefully replace the screws. It's a bit of a pain, but I think this might be your problem.
Hope that helps.
 
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