QuestionQUESTION: I have a 1997 Chrysler Sebring Convertible 2.5L Mitsubishi JXi. In very cold weather <15 degrees I get no heat. In warmer cold weather (>16)I get intermittent heat. When I stop the blown air is cold. When I move the temp goes up. I would very much appreciate you help on this one as I am not looking forward to another winter.
ANSWER: Hi Herb,
There are several possibilities, first assuming that the engine is running at the typical temperature as shown by the gauge on the cluster. The coolant flow through the heater core could be impaired by either air or dirt trapped in that pathway. Once the engine is warmed up touch the two hoses that flow from the engine compartment that are connected to the heater core in the cabin. They should feel similarly warm and if not then that would suggest the need to back flush the pathway by connecting a domestic water supply hose to the outlet side of the pathway. it is also possible that there is air instead of dirt in the line. Is there coolant shown to be present in the overflow bottle. If not, add to the proper level as shown by mark.
If the hoses feel similar in temperature then check the connection between the temp control knob and the lever that it is connected to by a cable. That lever controls the blend air door and it sends the blown air either over the heater core or over the A/C core at the extreme positions and in between in varying degree between the two extremes.
From what you described it appears that you do have good operation from your blower. Check the air intake located outside the vehicle in the channel in front of the windshield as it could be blocked with leaves.
Those are the ways to diagnose the problem.
Please read the PS (below( and respond to it.
Thanks for doing that.
Roland
---------- FOLLOW-UP ----------
QUESTION: Roland-
First of all i want to thank you for the precise and scholarly answer above. I am a research scientist and appreciate science art when I see it.
A quick follow up if you don't mind..If it turns out to be the cable that diverts the door to pass air over the heater then I just want to know if getting at the cable is a huge job.. or if I can get to the door and just force it open on the heating side? I have 1/4 million miles on it, I drive it daily, and I am not inclined to do elective procedures..While heat would be good I won't sink money into nonessential repairs
thank you
Herb
AnswerHi Herb,
The access to the cable and door is fairly easy involving removing the control panel to see whether the lever is moving through its range of motion. By feel after disconnecting the cable from the lever you should be able to tell if the internal door is moving or not. Dealing with a non-functional door inside the unit would require removal of the HVAC housing entirely.
To check out the cable and control lever you remove the trim bezel surrounding the controls and the radio (gently pry). Then remove the 5 screws exposed that surround the exposed area (for the cluster hood bezel and the control panel). Pry up the cluster hood bezel a few inches to expose the cubby bin/cigar lighter bezel screws and remove those, the remove the cubby and bezel. Then you should be able to drop the control module down into the bin area, remove its wiring and have a good view of the cable to lever connection. The cable is connected by a clip at the control end and to the lever at the other end.
Thanks for the rating/nomination and kind remarks. Feel free to repeat the rating/nomination.
Roland
