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Old 09-14-2018, 01:01 AM   #1
BCOWANWHEELS
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Heater blower need help

My 72 c10 with a/c only has low speed on the blower. Just replaced the blower motor, same results. What should i do next. Never worked on a/c equiped truck before. All help is appreciated a bunch............
Thanks
bob
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Old 09-14-2018, 01:25 AM   #2
Hutch
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Re: Heater blower need help

BCOWANWHEELS
Check the ground wire from the relay inside the cab on the firewall.
It is very short
It is located up high between the glove box and passenger side wall.

There is a short ground wire that is supposed to go one of the shroud bolts that come through the firewall
Easy test is to attach a short piece of wire while it is on high from the relay to ground.

A lot of folks do not get the ground re-attached correctly while working on the heater coil.

The symptoms are
Low= Low
Medium= Medium
High = Very SLow
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Old 09-14-2018, 01:51 AM   #3
BCOWANWHEELS
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Re: Heater blower need help

I havent got nothing but low speed. Even with oem blower motor
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Old 09-14-2018, 10:53 AM   #4
rockyrivermark
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Re: Heater blower need help

I'm not sure but do our trucks some a blower motor resistor? we know thats a very common problem on later models when one or more of the variable speeds go out.

isn't there something like a resistor that by the fan switch?

edit:
just looked it up.
this is what you need. it's mounted to the back of the fan control area i believe
https://www.classicparts.com/1960-72...iABEgLjq_D_BwE
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Old 09-14-2018, 01:30 PM   #5
BCOWANWHEELS
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Re: Heater blower need help

I bet thats it, could somebody tell me exactly where its located. I,am crippled and movement is real tough for me.
Bob
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Old 09-14-2018, 03:31 PM   #6
clay68c10
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Re: Heater blower need help

Maybe the resistor, but I'd suspect a bad switch first. Hi doesn't go thru the resistor, but low does. The switch is easy to get to and test. No sense spending money without a quick continuity test of the switch.
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Old 09-14-2018, 03:38 PM   #7
BCOWANWHEELS
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Re: Heater blower need help

Resistor is 10.00 at oreillys, i,ll check switch also. Thanks.
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Old 09-14-2018, 04:09 PM   #8
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Thumbs up Re: Heater blower need help

Here are some good info pages.
Most times on a AC truck it's the switch. It's a easy fix. I have fixed many of them by taking them a part and cleaning the contacts and regreasing them. A lot of times it's the plastic connector gets hot and melts and the terminals want make contact also.




This shows you where everything is.





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Get out and drive the truck this summer and have some fun!
It sucks not being able to hear!

LWB trucks rule, if you don't think so measure your SWB!
After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.
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Old 09-14-2018, 07:09 PM   #9
BCOWANWHEELS
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Re: Heater blower need help

perfect............ you blessed me tremendously.......... thanks bunches
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Old 09-14-2018, 07:11 PM   #10
Andy4639
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Thumbs up Re: Heater blower need help

Quote:
Originally Posted by BCOWANWHEELS View Post
perfect............ you blessed me tremendously.......... thanks bunches
Your welcome.
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1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver
Seeing the USA in a 71


Upstate SC GM Truck Club
2013,14 and 2016 Hot Rod Pour Tour


http://upstategmtrucks.com/



Get out and drive the truck this summer and have some fun!
It sucks not being able to hear!

LWB trucks rule, if you don't think so measure your SWB!
After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.
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