Heater/AC control troubleshoot - Chevelle Tech
Heating & Cooling Heating, cooling and air conditioning

 1Likes
  • 1 Post By Dean
 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 6 (permalink) Old Nov 16th, 19, 11:04 PM Thread Starter
Tech Team
 
Join Date: Jul 2004
Location: Ohio
Posts: 271
Heater/AC control troubleshoot

My blower motor does not work (brand new). I am not certain my Heater/AC control unit in dash is good. Is there anyway to check to make sure it is functional? 1970

Last edited by Ryan T; Nov 16th, 19 at 11:15 PM. Reason: Add year
Ryan T is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old Nov 17th, 19, 10:19 AM
Gold Founding Member
 
Join Date: Aug 1998
Location: 30.1298228, -97.9771166
Posts: 6,748
Garage
Re: Heater/AC control troubleshoot

There are 5 parts to the function of that system.
1. Blower motor.
2. Blower switch
3. Blower relay
4. Blower resistor
5. Wiring

If you have a test light and a shunt of wire you can pretty well troubleshoot the fault. If you have an ohmeter it would be even better for testing some parts.

The first thing I would do is check to make sure the electrical circuit has energy. Check for broken or disconnected wires. Check fuses under the dash and under the hood.
Next check to see the motor itself works by jumping a wire directly from the battery to the blower motor.
If both good, it could be as simple as replacing the relay or resistor. If you know the wiring diagram you can test those out rather than replacing.
The fan switches can fail but since they are mechanical they seem to be more durable than the resistors and relays which are electro mechanical.

We really need to know what you are capable of doing and what tools you have to proceed.

I donít like being manipulated!
Alan F is offline  
post #3 of 6 (permalink) Old Nov 17th, 19, 4:11 PM Thread Starter
Tech Team
 
Join Date: Jul 2004
Location: Ohio
Posts: 271
Re: Heater/AC control troubleshoot

I have a test lamp and multimeter. I have wiring diagrams just not real electrical savvy. Thanks in advance for your help.
Ryan T is offline  
 
post #4 of 6 (permalink) Old Mar 25th, 20, 9:21 AM Thread Starter
Tech Team
 
Join Date: Jul 2004
Location: Ohio
Posts: 271
Re: Heater/AC control troubleshoot

Sorry still working on this issue. Iíve tried to run a jumper...see below i posted on Facebook but not getting any responses.

Secondly the ground to the blower motor is good but if i put a jumper to try and power it the jumper sparks like crazy and the fusible link glows red. Instead of jumping from battery to blower i am jumping the red wire and purple wire in the pigtail thatís connects to relay. Now let me ask this also. If my heater box resistor is bad would that cause this to spark? But yesterday i tried same thing but went from battery to blower motor and it sparked a lot so i immediately stopped. Really struggling here. Lol
Ryan T is offline  
post #5 of 6 (permalink) Old Mar 25th, 20, 10:54 AM
Gold Founding Member
Administrator
 
Join Date: Aug 1998
Location: near Kansas City
Posts: 62,585
Garage
Re: Heater/AC control troubleshoot

IF any of the resister wires are grounding out, yes it will spark.
Try disconnecting the resister wires and jumper 12 volts directly to the motor lead.
LeoP likes this.

.
.
.
.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Dean is offline  
post #6 of 6 (permalink) Old Mar 25th, 20, 1:40 PM Thread Starter
Tech Team
 
Join Date: Jul 2004
Location: Ohio
Posts: 271
Re: Heater/AC control troubleshoot

Are you speaking of the blower motor resistor on the heater box? Disconnect that and the jumper straight to battery?
Ryan T is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in










Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome