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73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: jefferias on February 18, 2009, 07:40:07 pm

Title: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: jefferias on February 18, 2009, 07:40:07 pm

hi all hopefully you can help me out here.  went to the truck this morning for work and all was good, till i turned my blower fan on for the heater, and nothing happened. pulled the power wire off the motor and used a mutimeter to see if power was present and it was. so i figured blower motor no big deal.  picked up another unit and installed and still no worky worky.  checked power again and was still there, checked power when wire pllugged onto motor and no power- unplug it and i got power.  so my question is would these symptoms be maybe a "short" somewhere or the resistor unit is no good, but ifigured if the resistor was no good it would just blow on full power.  really scratching my head and it's -11celcius and gettin colder :-[

Title: Re: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: rockable on February 18, 2009, 08:28:42 pm

Have you got a good ground for the motor? 

Title: Re: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: jefferias on February 18, 2009, 08:32:18 pm

engine grounds ohh yeah i got em. bro works for electrical and got me some huge ground straps for free.

Title: Re: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: rockable on February 18, 2009, 08:36:23 pm

No.  I mean is the blower motor grounded?  Take your ohmeter and check to make sure.  Obviously, you've got a good ground on your meter when you check voltage.  Your motor cirucuit may not have a good ground.

Title: Re: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: jefferias on February 18, 2009, 08:41:52 pm

i will pull blower motor off and lightly sand the mounting surface and try that, looked pretty good when i put on though  but nonetheless thankx rock

Title: Re: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: rockable on February 18, 2009, 08:56:34 pm

Try hooking a ground jumper wire to it and see if it runs.

That's all I got, based on the information you gave.  Good luck!

Title: Re: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: jefferias on February 19, 2009, 08:30:54 pm

got it all working again !!  it turned out to be the fan speed switch , which is weird cause just replaced about 8 months ago, oh well no more "jobber crap" for me haha  thanx

Title: Re: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: rockable on February 19, 2009, 08:49:59 pm

Glad you got it fixed.  I don't understand why you had voltage unless the resistance was just really high through that switch, rather than open.

Oh well, at least you can be warm again! :)

Title: Re: Help!! no heat and its cacaca collldddd!!!!!!!!!!!!!
Post by: Prong on February 20, 2009, 04:30:30 am

I had the same problem about 10 days ago and it turned out to be the resistor. I'm glad it wasn't the switch, because then the radio and bezel has to come out  >:(  Hope yours went better.