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Help me TS my heater motor, please....

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livinginthepast

livinginthepast

Jedi Trainee
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Hi everyone,

I'm back with another request. The first thing you should know is that when it comes to electrics, I know even less than I do about mechanics, and those of you who know me can attest to my hardly achieving the rank of motivated novice in that arena.

That said, here are the details:
<ul style="list-style-type: disc">[*]60 Sprite[*]Positive ground[*]Heater motor in place[*]Heater switch in place and connected[*]All wiring appears to be in place[/list]
Turn the switch...Nothing.

I don't know if it's the switch, the motor or the wiring/connections.

Can someone walk me through this? I have a multimeter but I am ashamed to admit that I really don't know how to use it.

Thanks again for you help and your patience.

BillW
 
Got a Battery Charger? First see if motor will physically spin and is free. Trace wiring back to first spot where there is a bullet connector, pull apart, connect battery terminals to motor and I believe if someone else can chime in here on a positive ground car probably doesn't matter which way terminals are hooked up and connect.

I would disconnect battery BTW prior to trying this. If motor spins you'll know it is in your switch. And usually is in this switch. Go to Gerard's Garage web site and you'll find pics of a heater switch I took apart, cleaned off the green, and reassembled and now works fine 10 years later.
 
Ground doesn't matter when testing the motor as it will spin either way.

It's a toss up b/w testing the motor that way, or using the mulitimeter to see if you have power to the motor.


First off, lets learn to turn on and set the meter. Find the setting closest to, but above 12V DC and put the test leads on your battery ( red on + and black on -, my meter's closest setting is 20V). You should have a reading b/w 10.5-12.5 volts. If not, you're on the wrong scale, or your battery is not fully charged or dead. If you have a negative reading (-12.5), you have the leads reversed. I ALWAYS test the meter this way before trying to diagnos something. Play with the meter on circuts that are known to be good ( headlights, etc..)

Once you feel comfortable with your ability to set, read and probe with your meter, place a probe on each connector of both wires leading to the motor. ( unplug them from the motor first. These are the wires comming from the car to the motor. You should have two "bullet" connectors. UNplug them and shove the leads up in them. I like to go b/w the outer rubber insulator and the metal connector.


Bottom line, if you can use a rectal thermometer, you can use a multimeter. Just don't use a multimeter for such.
 
Thanks, Jim.

Ran a wire from the battery to the motor - it works.

So I guess it's probably in the switch. i'm on my way to Gerard's.

Thanks again!

BillW
 
kellysguy said:
Ground doesn't matter when testing the motor as it will spin either way.

It's a toss up b/w testing the motor that way, or using the mulitimeter to see if you have power to the motor.


First off, lets learn to turn on and set the meter...<snip>
Click to expand...

This is good - what I need to get started. Thank you for posting...I'm going out a little later and will put it into practice.
 
Check the fuse too. Make sure you have juice comming across the other side. Sometimes the fuse connectors get fouled when setting. Connections at the fuse box too. Work your way back.
 
Jim_Gruber said:
<snip> Go to Gerard's Garage web site and you'll find pics of a heater switch I took apart, cleaned off the green, and reassembled and now works fine 10 years later.
Click to expand...

My heater switch is different than that I see on Gerard's site. Perhaps I'm looking at the wrong page? My switch is sort of a combination turn/pull assembly. The Heater knob is attached to a central shaft that runs into the body of the switch (which sits behind the dash). The body of the switch is metal, round, little less than 2 inches in diameter and almost an inch thick. There are two wires, one on either side of the body of the switch, and a cable which is manipulated fwd and back by the pull/push functionality emerges from the center of the switch body and appears to control airflow.

I'm not sure how this thing would come apart...there are a couple places were it appears the main body of the housing as been bent to hold in place the back plate of the assembly. Maybe those can be carefully manipulated so the assembly can be pulled apart?
 
kellysguy said:
Check the fuse too. Make sure you have juice comming across the other side. Sometimes the fuse connectors get fouled when setting. Connections at the fuse box too. Work your way back.
Click to expand...

I'll need to dbl check to be sure all is well, but I recently removed and cleaned the fuse box, so I'm relatively confident that it checks out.
 
that may in its self be a clue,

when something stops working...... go to what was last done to vehicle and make sure this isn't causing your problem.

One of my first rules in trouble shooting. I have found what work I had done previously cause something eles to mal-function by something I did incorrectly
 
If you have voltage to the switch and gently wiggle the wires on the back of the switch and fan starts, I would suspect a loose spade on the switch. They are riveted on. The switch can carefully be disassembled with needle nosed pliers by gently bending the tabs to clear the back. On mine I found that over the decades, the detent ball had worn the 'cup' it sits in out, letting the ball move with the switch mechanism, and lifting the contact plate off the contacts. I tried to repair the cup but had little luck. Removed the ball and working fine since.

YMMV
 
MightyMidget: Critical point - the heater motor/switch has not worked for as long as I've owned the car, so there is no correlation between cleaning the fuse box and the heater's condition. Sorry about that; I should have made that clear.

leecreek: I'll try as you suggest. If the riveted wires are found to be the issue, can those rivets be tightened up somehow or could a small solder be applied to secure the connection?

thanks!
 
Of course, start messing with it and it will become self evident as to what you can do and can not.
 
You would need to be very frugal with the heat. Plastic bits inside switch. And the area would have to be clean to give the solder a chance to stick with minimal heat. A few heat sinks would be wise. You would just need a small 'bridge' between the rivet and the lug.
 
Sorry, I didn't realize you had a BE. I was assuming Spridget. My apologies. But at least you know blower runs ergo no power, either wiring or switch or something interupting power in between..
 
That switch is impossable to find so just go slow, it is repairable.
 
Part of the trick to getting it working is to find where the electricity stops. With a simple VOM Meter or even a 12 volt test lamp you can trace the wiring back from the motor and find where you need to go to to finally get 12VDC or light the lamp. The part in between is blocking the flow of current. You will liely find it in the swithch. If you find that there is 12VDC at the switch but not getting out that is your culprit.
 
Thanks for the tips. I'm going to get back on this saturday night. Wish me luck!
 
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