a/c heater fan motor amperage

[19newport67]

Does anyone know what the amperage for the fan motor should be?
1967 Chrysler Newport Custom
Mine blew fuse after running for 8 hours driving in 95 Plus deg day with a/c on
after letting sit for an hour i put a 15 amp fuse (original 20 amp) and runs OK.
I want to check amperage of the motor to make sure all is ok and it just was not the heat and
time running causing the fuse to blow.

 

[65 500]

I don't know what the draw is on those motors, but I would be surprised if it is even close to as much as 15 amps. I could be wrong though.

 

[Wildaugust]

I wouldn't be too surprised if the fuses aren't even all made to the same tolerances. I mean, look at how cheaply made a lot of stuff is these days. Almost everything seems to be made offshore and is of lower quality, than say, twenty years ago.

Just a thought.


If it helps at all, IIRC, I think my Ford tested at 7 amps on "HI".

 

[The Horvaths]

Modern replacements run about 2A without a load. The squirrel cage and ducting will load it, I would guess 5A might be typical on "high." Start-up current will be higher (briefly very high!). Heat changes things a bit. It also means that your fuse could be ever-so-slightly pre-heated. Did it blow when you jumped in the hot car and fired it up?

 

[The Horvaths]

Modern replacements run about 2A without a load. The squirrel cage and ducting will load it, I would guess 5A might be typical on "high." Start-up current will be higher (briefly very high!). Heat changes things a bit. It also means that your fuse could be ever-so-slightly pre-heated.

 

[19newport67]

Mine blew the fuse after about 6 + hours of running the a/c
outside temp 103 at the time and engine water temp 187

 

[Boomer]

Older motors draw more current than new, and as the windings age or absorb moisture, it can get worse. Not sure when they started putting sealed bearings into them, but a lot of older motors required lubrication to keep them from getting crudded up and dragging. Keep in mind that Chrysler probably didn't expect you to still be driving the car and using the fan quite this far down the road so the life expectancy of the motor might not have required it.

One thing to keep in mind: fuses have a lifespan of on/off cycles just like a light bulb. They can and do eventually burn out for no reason beyond age (think metal fatigue). 6 hours of load on an old fuse might've push it over the edge.

I'd check you fuse diagram before doing much else and make sure of the fuse size it requires. It might not bother again. If it blows relatively soon (a few days/week or so of regular use), something is causing problems. Could be as simple as a dirty or loose connection, or it could be a tired motor.

 

[19newport67]

Thanks for the info I will see if I can lube the bearings if not I will get the motor rebuilt