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Discussion Starter #1
For the last couple of years the blower fan in my 79 zx has been blowing fuses ( The one located on the blower motor) I took the fan out and found that the motor was almost frozen. I managed to drill a hole in the bottom and put some lubrication on the bearings which freed the motor up, the brushes and armature still looked good from what I could see. I put the fan back in and it got better for a while but would still blow fuses until one day the fan just stopped and hasn't worked since. Looking in the Haynes manuel electrical diagrams there are four parts to the fan, the motor, the controls, a relay and an unnamed box that I think is named the blower amplifier. The problem is I don't know exactly what it does or how to test it. If anyone has any ideas I would appricaiate them, my only other option is start replacing things.

Jared
 

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> For the last couple of years the blower fan
> in my 79 zx has been blowing fuses ( The one
> located on the blower motor) I took the fan
> out and found that the motor was almost
> frozen. I managed to drill a hole in the
> bottom and put some lubrication on the
> bearings which freed the motor up, the
> brushes and armature still looked good from
> what I could see. I put the fan back in and
> it got better for a while but would still
> blow fuses until one day the fan just
> stopped and hasn't worked since. Looking in
> the Haynes manuel electrical diagrams there
> are four parts to the fan, the motor, the
> controls, a relay and an unnamed box that I
> think is named the blower amplifier. The
> problem is I don't know exactly what it does
> or how to test it. If anyone has any ideas I
> would appricaiate them, my only other option
> is start replacing things.

> Jared
Well welcome to the club! the unnamed box in the diagram is indeed an amplifier, the relay is for air conditioned models. won't effect the heat mode of operation,my 79zx doesn't have air so no relay. the factory manual may have a test procedure
for the amp, I havent seen it, the amp is mounted next to the blower motor on the bottom of the housing, has four wires on one plug,colors:green,black,blue and blue red, take out the two screws that hold it up in the housing and drop it out,pull back the boot and pop out the amp from the can,it snaps into the can,inspect it for rust,burnt odor,or cracked circuit traces. mine was water damaged. yours may have over loaded from the motor being siezed up and may be bypassing too much current.
check the motor by bypassing the controls,hook up agood ground and power directly to the motor. stealyour power from the top of the heater circuit fuse,
if the fuse blows after a little bit of operation, the blower motor is the culprit.

check out the parts for sale section here at zcar.com and save yourself some change.
sorry this got so long but I just went through the same thing.
 

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> Well welcome to the club! the unnamed box in
> the diagram is indeed an amplifier, the
> relay is for air conditioned models. won't
> effect the heat mode of operation,my 79zx
> doesn't have air so no relay. the factory
> manual may have a test procedure
> for the amp, I havent seen it, the amp is
> mounted next to the blower motor on the
> bottom of the housing, has four wires on one
> plug,colors:green,black,blue and blue red,
> take out the two screws that hold it up in
> the housing and drop it out,pull back the
> boot and pop out the amp from the can,it
> snaps into the can,inspect it for rust,burnt
> odor,or cracked circuit traces. mine was
> water damaged. yours may have over loaded
> from the motor being siezed up and may be
> bypassing too much current.
> check the motor by bypassing the
> controls,hook up agood ground and power
> directly to the motor. stealyour power from
> the top of the heater circuit fuse,
> if the fuse blows after a little bit of
> operation, the blower motor is the culprit.

> check out the parts for sale section here at
> zcar.com and save yourself some change.
> sorry this got so long but I just went
> through the same thing.
one mistake on last nights message, take the power for the fan from the bottom of the fuse, if you take it from the top the fuse won't see the load, noticed that this morning when i went to the store. keep safe.
 

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Discussion Starter #4
Took a trip out to riteway auto parts in phoenix today, picked up a new fan and amp just to be safe. $85 and the fan works great - thanks

jared
 
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