The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 11-26-2017, 04:18 PM   #1
Bennydog
Registered User
 
Bennydog's Avatar
 
Join Date: Jun 2009
Location: Corona Ca
Posts: 94
A/C Heater Blower Problems

Hello I have a 75 C10 with heater and air conditioning. RPO C60.. My heater was not blowing so i decided to fix it. got new relay, resistor, blower motor, and switch inside. It runs when key is on in low like it should. It works in low medium 1, and medium 2. But blows fuse in High. I have checked all grounds and jumped ground to fan and it works fine. I noticed this 2 connector under the relay, and sure enough when i unplug it it does not pop the fuse and just goes back to low speed when high is selected. When i put a light on the connector the orange wire gets power only when high speed is selected. so i unbolted it and it has one wire running through the heater core.. WHAT the hell is this thing... Please help!
Attached Images
   
__________________
Grandpas and Dads and now my 1965 C-10
1975 SWB C-10
Bennydog is offline   Reply With Quote
Old 11-26-2017, 04:33 PM   #2
Dead Parrot
Registered User
 
Join Date: Aug 2012
Location: Oklahoma City, OK
Posts: 2,461
Re: A/C Heater Blower Problems

That is the anti-freeze up thermostat for the AC side. It should NOT be in series with the blower motor relay. It should be in series with the high pressure cutoff switch on the other side of the dryer in your picture.

Just looked at my 75 with AC. The connector with the orange and black wire should go on to your relay where the connectors with the green wires are in your pic. The connector with the green wires goes to the AC thermostat.
Dead Parrot is offline   Reply With Quote
Old 11-26-2017, 04:51 PM   #3
Bennydog
Registered User
 
Bennydog's Avatar
 
Join Date: Jun 2009
Location: Corona Ca
Posts: 94
Re: A/C Heater Blower Problems

Thank you Sir, That was it. Never trust a previous owners wiring.. Thank you SO much. Everything works tops now!
__________________
Grandpas and Dads and now my 1965 C-10
1975 SWB C-10
Bennydog is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:33 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com