Heater Resister

[VTMopar]

Hi   All      the fan on my '70 runs all the time and someone mentioned that the "heater resistor" might be the culprit.   Where is this -- and what the heck does it look like?     

Thanks for you help!

Vermont MOPAR

[DAYLEY/CHALLENGER]

I thought I had a pic of one but I only have the pic where it goes........It is the  spiral wound wire mounted on the plate that is inserted into the heater box.  At least I think it is.       Anyway, a pic of the box where this thing is mounted.........It mounts in the rec. shaped opening...........

[Slotts]

Hey Vermont MOPAR,

Here's a picture of the resistor coil plate. DC is right and the spiral end is on the underside of the circuit board.  I really dought that is your fan problem. Something upstream is feeding voltage down the line to cause the fan to run constantly. A place to start would be checking if the motor is running on low or high speed.

Slotts

[BP23G0B]

Mine seems to be running on low all the time.  The air is always hot.  Could the vent be frozen open? 

[VTMopar]

Thanks for the pics on the resister.    I can't tell if it is running on low or high -- its just on one speed all the time (switch doesn't make a difference).    What is weird, however,  is that when either door opens, the fan goes off!

I've also noticed that my map light doesn't come on when the doors open (while the interior lights work fine   -- this is a convertible).....

So, some have suggested I have a ground problem...... I guess I just need to gear up and start tracing wires!

Vermont MOPAR

[Chryco Psycho]

you need to trace the wires , the door switch is just a ground switch to turn on the interior lights so something has to be wrong at the map light , & the connection to the heater

[VTMopar]

Chryco - Do you think the two issues are related -- or independent gremlins?   

Vermont MOPAR

[Bullitt-]

Sounds like the map lamp ground is connected somehow to the heater resistor.
Heater wires are DGN- dark green , high speed, & LGN- light green ,low speed.
Map light is 18Y yellow. I remember someone had issues caused by the time delay ground being misplaced.

http://www.mymopar.com/downloads/1970/70ChallengerRallyeclusterdashA.JPG

http://www.mymopar.com/downloads/1970/70ChallengerRallyeclusterdashB.JPG

[VTMopar]

Thanks Bullitt -- are the color codes on those wires different for a non-rallye dash?   

Vermont MOAR

[Bullitt-]

I doubt that they are different but in this schematic they refer to YELLOW or YEL-TR for the door switch to delay

http://www.mymopar.com/downloads/1970/70ChallengerB.JPG

   and the same DK GREEN & LT GREEN for the "HEATER MOTOR SW."  Switch to Resistor wires.
I do notice a LT GREEN wire going to the DELAY RELAY in the bottom right .

http://www.mymopar.com/downloads/1970/70ChallengerA.JPG

[VTMopar]

I found it!         Someone interchanged the connections for the heater fan with the map light!     No wonder the fan ran all the time (except when the door opened) and the map light wouldn't work.    Hook them up properly and PRESTO -- map light comes on when doors open and heater fan works as it should!    Interestingly, my radio used to have volume issues (was always rather loud)  -- now the volume control seems to work normal (I don't quite understand how this was related -- but it seemed to be!)   Thanks to all for their advice and help!    Tracing the wires is the trick!

Vermont MOPAR

[Bullitt-]