Blower motor help on 87 1500 305!

[michael.shelby.988]

Hello, I am new to this site and have a question relating to my blower motor... I striped my truck of the AC because it's winter and well it wasn't working in the Summer. I ha to replace my heater core due to a hole in it got it replaced as well as my AC stripped out...but now my blower motor will not work. I don't know if it's the relay or what I'm stumped.


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[Boone83K10]

Did you remove the resistor on the ac box on the firewall?

 

[michael.shelby.988]

No I didn't remove it. I have it plugged in from the relay? I'm stumped!


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[bd]

Hello Michael.

Is the blower motor plugged in and the ground wire connected?  Have you checked the fuses?  Did the harness connectors pull loose from the dashboard control?

What have you done so far to diagnose it?

[michael.shelby.988]

I've checked the fuse under the wheel (15a) it was fine the harness connectors didn't come loose I checked them. Ground wire is connected to a clean ground. The only thing I don't not understand is if the resistor does?! Like previously stated my whole AC unit is taken out of the truck


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[bd]

...The only thing I don't not understand is if the resistor does?!...

The resistor drops the voltage to the blower motor to control fan speed.  Do you have a test light?

[michael.shelby.988]

I do have a test light would I just check the two prong like things on the inside of that box? Or the plug it self?


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[bd]

Referring to "prong like things" is a little vague.  Begin by clipping your test light to a clean ground and probing the battery positive terminal to verify the test light and its ground connection.  Now, w/o moving the ground clip, turn the ignition on and probe the purple wire connecting to the blower motor - does the test light illuminate?

[michael.shelby.988]

I'll have to check on tomorrow it's 11 over here in the east coast. So say the test light illuminated then could it possible just be that my blower motor burnt out?


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[bd]

If the test light illuminates, then probe the bare metal of the blower motor's steel frame.  If the test light illuminates when probing the blower frame, the blower motor isn't properly grounded.

If the purple wire probes hot while it's connected to the blower motor and you've verified the blower frame is properly grounded, then run a temporary jumper from battery positive directly to the blower motor terminal.  If the blower still doesn't work, replace it.  Let us know what happens.

[michael.shelby.988]

It was the ground! I tinkered with it cleaning the metal up and plugged it in and she started blowing! Thank you so much for your help bd!


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[bd]

You're quite welcome.

[christopher.lafollette]

It was the ground! I tinkered with it cleaning the metal up and plugged it in and she started blowing! Thank you so much for your help bd!


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I had the same thing happen, my ground actually vibrated loose, I thought the motor was fried.