How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Chris Your Own Question
Chris, Shop Foreman
Category: Dodge
Satisfied Customers: 13654
Experience:  Dodge/Cummins and Chrysler Certified Master Tech
Type Your Dodge Question Here...
Chris is online now
A new question is answered every 9 seconds

MY 1986 DODGE Diplomat with about 13,000 original miles

This answer was rated:

MY 1986 DODGE Diplomat with about 13,000 original miles (almost unused) was running well until three days ago. Suddenly the controls for the heater would not work. No matter how they were set there is no heat for the windshield or the floor after a few seconds. The buttons on the control panel do not seem to do anything. There is no evidence of any air valves controlling air flow. The only other problem I have had with it was that the heater button would get moderately hot after a time when using the heater but that is not the case now. The Air conditioner works fine as does the fan. I have not been able to check the valves to the hoses to the heater.There seems to be no
JA: Have you checked to make sure the thermostat is working? What about the coolant level?
Customer: I had all levels checked about 10 days ago. The temperature gauge reads normal. The lack of air flow seems to indicate that something is blocking the air flow. IT is as if a vacuum hose has broken or dropped off but I still do not understand the workings of the control unit and activators.
JA: Are you fixing your Diplomat yourself? What have you tried so far?
Customer: I ave not made any changes or adjustments. I may take it to a dealer but I am concerned that there are not so many mechanics with experience on these older cars. I am waiting for a back operation so it is not easy to reach the parts.
JA: Anything else you want the mechanic to know before I connect you?
Customer: Not that I can think of.

Hello , my name is ***** ***** I will be assisting you today . I used to work on those vehicles back in the day , and I bet a vacuum hose became disconnected from the vacuum port ubder the hood. The doors are vacuum operated. i believe that the vacuum line connected to a port at the brake booster on the left side of the firewall . so first take a look there and then report back to me


Hello, just checking back to see if you received my answer. Please let me know if you did or did not. I can always send it again if necessary.

Thank you!


Customer: replied 8 months ago.
I called the two Dodge Dealers in the city and asked if they had any older mechanics who would be familiar with vacuum controlled heating and AC systems. They both said that they did and that they would assign the older mechanic to work on the car. I told them that it was probably a broken hose or cracked vacuum control hose and I just needed them to check the hoses. I said that I did not want anything replaced. They both said that they could do it. I had a little experience with one of the dealers so I chose that one partly also because they could accommodate me sooner and the defrost is needed for driving.Both my adult son and I had checked the coolant level and it was fine and looked in great condition. We each separately confirmed how the system was reacting. I did not have my inspection scope with color video output so I could not do as complete an inspection under the dash as I would normally do. The temperature of the coolant was running at its usual level, just below the mid point. I had the original dealer In Manitoba change the thermostat and the coolant hoses and flush the system and heater core before I drove the car across the prairies and the rocky mountains in winter (a few years ago and about 8,000 miles ago. The other fluids were also changed and what was taken out was in good shape. I am now on the west coast and keep the car in first class storage for most of the time. They run the car occasionally and check fluid and air pressure in the tires. I have been taking the car out of storage once or twice a year and driving it for a few hundred miles. Each time I check to see that the heater and AC are working (and brakes of course).Since your analysis agreed with my son's and mine, I felt confident in just having the mechanics check the hoses. Being typical modern mechanics they assumed that if there is not enough heat that the thermostat is gone. I usually remove thermostats myself and test the units before replacing just to see if they were really faulty.The mechanics insisted in flushing the system and heater core, but back flushed it after putting in the new thermostat. They managed to blow the new gasket. Later they said that they had checked the temperature of the supply and return to to the Rad and heater but I am not so sure this happened. They claimed that the coolant was full of crud but never showed me any proof. They first said that the controls were working and air flow was normal but then later said that there was no vacuum. They tried using another source of vacuum but gave no info on the results. They claim that the whole control unit needs replacing. They also say the heater core needs replacing.It is my feeling that the other mechanics were ribbing the mechanic about having to work on such an old car and inferring that he (and she (helper)) were not capable of working on newer cars. This is gleaned from the snide comments that he made to the service manager and that I overheard on a few occasions.The mechanics did remove the dash to check the operation of the doors and actuators and said that they were working fine. I assume that this was with another vacuum source as they still claim that there is no vacuum. The messed up the re-installation of the dash and it does not fit properly and the glove compartment door will only open a small amount.In case you are wondering, the car is in immaculate shape otherwise and is very striking. I get lots of thumbs up on the car and people taking pictures of it or even asking if I want to sell it. (A lot of nostalgia,) This is in a city where there are many old vintage cars.I am trying to keep the car in original condition, as I have to sell it, as my arthritic wife is not able manage to drive it.
I am looking for a garage that specializes in antique cars. It is hard to get references on most of them.The bill for the clowns at the dealer's was $ 769.91. They want me to drive it "as it may clear itself "!!. The air flow is as it was before and there is no heat or defrost air flow and now the AC does not work. The latter may be because the weather is to cool but I am not sure.I would appreciate any guidance. Thanks for your assistance so far.Cliff Shirtliffe

Cliff I still do not understand why the shop did not find and fix the loss of vacuum to the control panel. Especially since they even admitted that there is no vacuum. That should be fairly simple I think.


Chris and 3 other Dodge Specialists are ready to help you

Related Dodge Questions