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 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 06-16-2020, 06:02 PM   #1
sick472
Registered User
 
sick472's Avatar
 
Join Date: Jul 2015
Location: Sedalia Mo.
Posts: 1,131
Fan Switch Testing Question/s

I am troubleshooting my wiring harness and have disassembled the fan speed switch and cleaned it up because is was transferring little to no power through the switch. It was pretty gummed up inside. This is on a 72 with A/C (A/DC to be deleted). The switch is now showing life. This is what I get with my conductivity meter...

Using "B" for the power terminal (brown wire),

No power throughput to any of the other terminals in the OFF position (good).

Power at the "L" terminal in Low position (seems right),
Power at the "L" and "M" terminal in Medium position (seems odd to be using both resisters for medium speed - I'd thought that might be a Low function),
And, Power at the "L" and "H" in the High position (really seems odd, maybe the Low feed is denied at the relay?).

Is this right? I am having trouble wrapping my head around how the fan speed switch, relay, and resister set works together. I've got the wiring diagram, but still miffed. Re-pop switches are cheap, but I am just stubborn that way...a good challenge and learning experience = priceless. lol

Anybody teach an old dog new tricks?
Attached Images
 
__________________
He who is without oil shall throw the first rod. Compressions 8.7:1

1972 C10
1976 C10 (parts truck)
1985 K20
sick472 is offline   Reply With Quote
 

Bookmarks


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 06:02 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com