switch for blow motor

[chevyboy1983]

i have a 1983 chevy 4x4.  I have a problem with the hvac control on the dash.  I replaced the blow motor but still nothing is there a way for me to test the wiring leading up to determin the switch is bad b4 i buy something i dont need

Thanks

[77c15]

Is your truck an original a/c truck? Mine was, and I thought the switch was bad too, until I looked at the wiring diagram and figured it must be the blower motor resistor or relay....it was the relay. I would guess that yours may be bad also. I don't have the a/c connected, but I did need heat.

[chevyboy1983]

Is your truck an original a/c truck? Mine was, and I thought the switch was bad too, until I looked at the wiring diagram and figured it must be the blower motor resistor or relay....it was the relay. I would guess that yours may be bad also. I don't have the a/c connected, but I did need heat.

yea it does have factory ac also but not hooked up cause of a sezied compressor. 

[77c15]

Then I would spend the $10 and replace your relay after you've tested the old one. Make sure all of your wires are connected properly, especially the ground wire coming off of the blower motor housing.

[VileZambonie]

Get a test light and go right to the source of the problem. Take a test light to ground and see if you have B+ at the blower motor in any position. If no, and you have a factory AC harness jump back to the AC blower relay and see if you have it there at the other large wire. If no B+ there check the fuse. If the fuse is ok check the switch.

[77c15]

The B+ is not only the thickest of the grouped wires, but is usually quite bright in color. Most are red, yellow, or orange. You should be able to tell that it is a good bit thicker than the others. This is the main wire used to bypass the blower resistor (low=3v, med=6v, med.high=9v, high=straight 12v, bypassing the resistor).

[Dragon]

Just out of curiosity, since you replaced the Blower Motor, are you sure you replaced it with the right motor???  An AC & Non AC truck have two different motors, and you would be suprised at how often the Wrong motor gets swapped in(Especially if you got it from a Parts Gimp who was too lazy to get you the right part in the first place!)....  Sure a Non AC motor will/somewhat fit in an AC truck, but you can't use the AC in a Non AC...   

Also who did you get the replacement motor from??? Was it a Wrecking Yard piece, AC Delco/Dealership Reman/New, or was it a New/Reman from a Parts Store like NAPA/Autozone/Etc???  I ask, as it can be hit or miss/miss miss when it is a Parts Store Reman, to a point that you may go through a few before you got one that worked/worked correctly....

[77c15]

I went through the same ordeal with my blower motor. Beware of the ones from AutoZone. I got one and the shaft the squirrel cage attaches to was to long and actually pushed the cage into the firewall and I couldn't even get the bolts started and I could tell that if I hooked it up it wouldn't turn because it would bind. The one I got from Advance dropped right in and looked almost identical to the one I took out. Advance had the motor listed to work for both a/c and non-a/c trucks, though.

[chevyboy1983]

well it didnt work at all when i bought the truck i replaced the blower motor and still nothing i dont even here it click when i turn it on or anything. So that is why im thinking it might be the switch.

[77c15]

Please replace the relay first. If that doesn't work, replace the blower motor resistor. If that doesn't work, the switch (most expensive of the fixes) would be the last resort. I would much rather knock out the cheaper stuff now than later. If you want to have the peace of mind and have the cash, replace all of them. The a/c electrical system isn't that hard to follow if you understand how the system works with the voltage, which I tried to explain in my above post. I guess I could've compared the speeds to going all the way from a watch battery to a "D", but it may have complicated things worse.

[Dragon]

I went through the same ordeal with my blower motor. Beware of the ones from AutoZone. I got one and the shaft the squirrel cage attaches to was to long and actually pushed the cage into the firewall and I couldn't even get the bolts started and I could tell that if I hooked it up it wouldn't turn because it would bind. The one I got from Advance dropped right in and looked almost identical to the one I took out. Advance had the motor listed to work for both a/c and non-a/c trucks, though.

The one you got from AZ was an AC model that you tried to mount in a Non Factory AC Truck.  An AC Blower has a Larger Squirrel Cage, and a different Mounting Bolt Pattern(The mounting plate can also have a different shape as well)..  As for Advance, more than likely the Parts Tech didn't know his ___ from a hole in the Ground...  The Confusing thing about the EPC(Electronic Parts Catalog) that most major Parts Stores use, is that they aren't very clear in the description.... 

Your case, you got a Blower Motor for a truck with AC, but without the Squirrel Cage installed
 Here's two Examples of what you would find on a Typical EPC(found on partsamer)

1)Ready-Aire Blower Motor
Blower Motor: Without Wheel With Air Conditioning
Warranty: Limited 1 Year*

2)Siemens A/C & Heater Fan Motor
Blower Motor: With Air Conditioning
Warranty: Limited 1 Year*

Number 1 is a AC Blower Motor without the Squirrel Cage, but being on a typical Black & White/Green/Etc EPC, it looks as if it is a Universal Blower Motor for trucks With or Without AC....

Number 2 is again a Blower Motor for a Truck with AC.. On an EPC, it looks like the Truck has a seperate Blower Motor for the Heater & one for Air, and this motor can be used in either locations...

Most EPC's are generally a Black or Dark Gray Screen Background, with White/Green/Blue/Red/Gray/or Yellow depending on the Parts Store, which actually makes it difficult to read & remember all of the description at one time....  Sure it is easy to read on a Full Color Screen like you or I may have, but in most Parts Store cases, you only look at part of the description to give you an idea... Only look at part of the description can cause you to miss the important parts, but most Parts Techs either have other Customers waiting,Don't have an interest with helping finding the right parts for that person, or the Tech doesn't have enough training to understand what they are looking for(Generally the Biggest Problem with these Parts Stores, is that most of the Employees may only have Basic Automotive Knowledge at best!!!)...


Chevyboy, in your case, I agree with 77C15, and suggest that you start with the smaller parts first, or if you can afford to, replace as many pieces as possible...  It is an old truck, and the parts will need to be replaced eventually, so why wait??

[77c15]

My truck has a/c. And at all of the Auto Zone's, the old black and green EPC is gone. They introduced ZNet right before I got there last year and it's more like a web browser with hyperlinks than anything else.