msk914

'65, no A/C. When I got the car, the blower motor did not run, I put in a new one, it ran. (I only tested it for 30 seconds or so -- and it only ran in high speed.) I turned it on today, it was cold here this morning, it blew after a minute. I replaced the 10amp fuse, which was fried, it then blew the second fuse after about a minute or so of running.

I need to test the capacitor, but I think it could also be shorting through the resistor (which I know does not work). Even if the problem is the capacitor or something else, I'd like to replace the resistor (my OCD). Where is this resistor located? Is it up behind the switch in the console near the clock? Is a bad resistor likely to cause the fuse to blow at high speed?

thanks,

Mark

buns

The resistor is located on the side of the inner heater box.

If you're talking about the capacitor plugged into the blower motor, you can remove that and connect the orange wire directly to the motor. It's only for AM radio noise suppression.

msk914

Thank you sir.

I figured out the capacitor use from reading the forum, so I will try that shortly.

About the resistor though: Where is the inner heater box? Is that in the cabin under the glovebox? Or somewhere in the engine compartment?

Mark

buns

Yes, in the cabin, under the glove box, just to the right of the radio. Wires are Orange, Yellow and Light Blue with a black tracer.

buns

This is what you are looking for:



.

msk914

Thanks. I will check it out shortly.

JohnZ

And here's where it's located.

msk914

I found it. Thanks everyone. I unplugged it. I replugged the power lead to the motor without the capacitor. The motor stayed on for about 3 seconds before blowing power. Worse than before, argh.

Any ideas what else to look for? (The motor is new, I know this might mean something or nothing....but putting in a new motor is such a pain, I'd like to explore other possible problems before going on to replacing it. )

Mark

dplotkin

Quote:

Originally Posted by msk914

Any ideas what else to look for?

Fuses blow from excessive current, so one of two things are happening, either you are running the wrong fuse (check to make sure it is the correct rating) or the new motor for what ever reason including being the wrong spec or defective, is drawing excessive current. Where did the new motor come from? Are you sure nothing is binding on the impeller (squirrel cage) as any drag on the motor will cause inordinate current draw. On an A/C car I think high speed works through a relay to isolate it from the resistor, so get out your diagram and examine all the associated wiring. Also, put a DVM set to DC amps between the wire & the motor lug, switch it on & report back on reading.

Dan

msk914

Dan,

Thanks. It is a new motor from one of the major suppliers, probably Ecklers. The car is not A/C. The fuse is 10amps, which is the spec for the heater. Until today, when I got the capacitor and the resistor out of the circuit, it would run for ~30-60 seconds before blowing the fuse. Today, after putting in a new fuse, with no capacitor and no resistor, it blew almost immediately. Strange. Do you mean Digital Volt Meter? I have a meter but it is not fancy enough to record (and it does not have clips either, just probes).

But the behaviour, sadly, is like a motor problem, with it getting worse...
fuses are easy, I think I will put back the capacitor, put back the resistor clip, put in a new fuse, see how long them motor runs. If it fails quickly again, I guess I will assume it is a bad motor, I need the resistor, so I could buy another motor ($20), the resistor, put it all back in, and see what happens. Which I hate to do....ideas???

Mark

buns

I would pull the motor out and bench test it. Just use some alligator clips and run a fuse inline to the motor.

skids

Mark,

I have the same problem on my 64, no AC. Installed new motor and resistor, and will blow fuse after a running on high for a brief spell. Never really did use the fan anyway.

dplotkin

You both have new motors. My guess is they are the same motor and one requiring more current than the stock wiring can handle. I'm curious as to what the draw is, can you use a volt ohm meter in series and tell us the amperage draw?

Dan

msk914

Hard to do: The motor, which stayed on for 30-40 seconds until today, now kills the fuse almost immediately. I'll try though....

Mark

buns

Don't do it! Most meters are only good for 10 amps and are unfused. You will fry it if you are already blowing a 10 amp fuse.

msk914

I'm just going to pull the motor when I have a free hour, test it from an outside power source (with a fuse). I am sure it is bad anyway, so once I do this, I'll just get a replacement and a resistor.

thanks for all the help everyone.

Mark

Jackfit

The new motors require a stronger fuse. Go up one from 10 to 15 and it will not blow.

Did it 4 years ago and no problems

Jack

dplotkin

Well, if you have a $14 meter from a discount store like the one most people have, yes you are correct & I forgot about that...though those meters are usually fused but not worth opening up to change it.

I'm uncomfortable up-sizing the blower fuse. Remember the fuse is sized to the conductor size, not just the expected draw of the load.

If John Z and other veterans say it's OK than it's OK. Otherwise, being an electrical kind of guy I frown on fooling around with over-current protection since an error can burn down your car, your house and you too.

If all that's available is a replacement motor that draws more than 10 amps I think I would wire in a relay (similar to what many fellas here do for headlamps). Use the 10 amp feed to drive a relay coil. Use the relay contacts to close and open a new circuit FUSED at 15 amps and wired with #14 gauge stranded. It will work on high only, if you want to retain speed control it will take more wiring.

Easiest thing is to find an original, working motor. They exist. I've bought them for other old GM cars I have.

Dan

msk914

The wiring can take more than 10amps, so I put in a 15amp fuse. It works perfectly. Thanks Jack. I had the motor running (high speed) for 3-4 minutes, turned it off and on a few times. No problems, no smoke, no hot wires, nothing but a spinning motor. I wish the supplier had told me. Now on to buying a new resistor to make low and medium speed work too.

Mark