59 Heater Motor ground

[Pat H.]

In in the process of redoing my 59 and want to ensure each part functions before moving to the next part installation. Prior to the restoration, my heater diverter box was a steel replacement connected to the blower assembly. I've replaced it with a repro version of the cardboard (fibreboard) original style. Once everything was installed, I tried the fan and nothing worked. I re-check my wiring diagram and everything appears to be in the right place. I place a jumper wire from the cable to the blower housing and it worked, but seems to be spinning faster than before. On low speed the resister (coil on the switch) get real hot but it seems okay on high speed. Am I missing something. I think prior to the restoration the metal diverter was acting as a ground to the blower housing.

[John H.]

Re: 59 Heater Motor ground

In in the process of redoing my 59 and want to ensure each part functions before moving to the next part installation. Prior to the restoration, my heater diverter box was a steel replacement connected to the blower assembly. I've replaced it with a repro version of the cardboard (fibreboard) original style. Once everything was installed, I tried the fan and nothing worked. I re-check my wiring diagram and everything appears to be in the right place. I place a jumper wire from the cable to the blower housing and it worked, but seems to be spinning faster than before. On low speed the resister (coil on the switch) get real hot but it seems okay on high speed. Am I missing something. I think prior to the restoration the metal diverter was acting as a ground to the blower housing.

Pat -

Originally, there was no separate ground wire for the heater blower - the Rube Goldberg Electrical Designer instead used the temperature control cable sheath as the ground path back to the center console trim plate through the cable knob and bezel; the trim plate had a tapped boss on the back side for a ground wire that served the console, and also served as a remote ground for the blower motor. Probably got a bonus for eliminating the ground wire.

[Richard M.]

Re: 59 Heater Motor ground

Great descriptive John!

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Yup, and the other end of the Heater TEMP control cable, which is mounted to the Center Console plate,

attaches to the heater control valve, attached with 2 sheetmetal recessed head screws,

which gets mounted to the metal bracket sandwhiched inside the heater box,

which has holes for 4 mount studs of the cage sandwhiched inside the heater box,

which then attaches it to the cage with Palnuts to continue the ground path,

which mount eventually through it's recessed head mount screws of the round plate which holds the blower motor,

which gets attached to the 2 long blower motor housing bolts,

which get attached to the plate with the extended studs of the motor sticking out,

which go though the mount plate held by 2 additional machine nuts to the motor mount plate......

...to get ground.

Simple!

Rich
p.s. Sidenote.......Too much paint on these connection surfaces will prevent a good ground path. Always scratch up the mount points of everything to ensure all connections are clean metal

p.s.s. Pat, it's normal for the resistor to get hot as it's designed to drop the voltage to the motor, therefore it draws a few amps in the process.

[Pat H.]

Re: 59 Heater Motor ground

I think tomorrow, I'll try and remove the blower motor and check to see if I have a gasket where it shouldn't be. I also found a thread in the archives that said to place star washers on the blower switch and the ground on the back opt the console plate.

[Pat H.]

Re: 59 Heater Motor ground

Rich,
I just found a photo of my rebuilt heater assembly and I noticed that I place a foam gasket between the plate that the water valve is attached to. Is this the ground I'm missing. I just reviewed your completed unit and I can't see any type of gaskets on any of the metal parts. There were a lot of gaskets and seals in the kit from CC that I did not used as they were not on the blower when I took it apart.

[Richard M.]

Re: 59 Heater Motor ground

Pat,

Yes a foam seal goes on the plate(that the valve attaches to) to the fiberglass heater box itself. The kits come with 2 seals for that, but only one was ever used. Don't use one on the other side of the plate. The other side of the plate faces the blower squirrel cage and gets its ground through the 4 Palnuts and squeezed plate to the cage. Yes good to use star washers for a good bite to get a good ground.

Either way, a good test is just a Ohm meter and check continuity between the motor case and the heat control valve mount screws and valve cable clip. This will tell you if you have a good ground or not.

Rich

[Pat H.]

Re: 59 Heater Motor ground

Rich/John
Thanks for the info on the heater ground. I found the problem yesterday. I added the second foam seal between the water valve plate and the blower housing. After removing it everything worked.

[Richard M.]

Re: 59 Heater Motor ground

Good catch! I had a strange feeling that extra seal may have been in there. Why the vendors put 2 in the kit is misleading and makes folks use it, just to wind up with a a ground problem like yours.

Rich