| Low Coolant Module [message #282020] |
Mon, 13 July 2015 16:50  |
 |
thainglo
Messages: 132
Registered: March 2015
Location: Iowa
Karma:
|
Senior Member |
|
|
While flushing the coolant in my new 76 Eleganza, I decided to check on the low coolant detection system. Even with the radiator drained, no light came on the module (ignition switch in RUN). Read thru the service manual and its troubleshooting procedures. Disconnected single wire from sensor, no light. Checked fuse (which should have been the first step imho), still no light. Points to either a grounded circuit or bad module. With e wire disconnected from the probe, no continuity was found to ground, so I'm guessing bad module.
Went digging around the forum and found Gene's pictures of his module and the schematic:
http://www.gmcmhphotos.com/photos/low-coolant-module/p47339-img-28332.html
Mine looks similar, but is a three wire system, not four. Pink (12v), black (ground) and yellow (probe).
The guts are different as well. While Gene's shows an integrated circuit, mine is straight resisters and transistors.
http://www.gmcmhphotos.com/photos/miscellaneous/p58457-low-coolant-module.html
So a couple of questions:
1) anyone familiar with how the system functions? Based on what I'm seeing in the board, I'm guessing the probe is heated up then some how tested for signal? If it just went to ground when the coolant was low, that could be wired directly to the LED.
2) is there a detailed schematic out there to troubleshoot?
The module jimk has also shows the four/five wire system, so im guessing that won't do the trick either.
Regardless, not the end of the world, but it got me curious.
Thanks for any help!
Matt
Matt Sladek
1976 Eleganza II
Coralville, IA
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
