Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-28-2017, 07:30 PM   #1
Member
 
City: Miami
Vessel Name: Naut-A-Yacht
Vessel Model: Mainship
Join Date: Nov 2015
Posts: 6
Thermistor

Hi All,
What does the thermistor do on the aftercooler of my Cummins? I have a 6BTA with turbocharger. Looked at the wiring diagram and can't figure it out. I think it shuts down the turbo when it detects high temps in the aftercooler.

Thanks!
__________________
Advertisement

Rimshot is offline   Reply With Quote
Old 06-28-2017, 08:25 PM   #2
Guru
 
LarryM's Avatar
 
City: League City, TX
Vessel Name: Pelago
Vessel Model: Wellcraft 3300 Coastal
Join Date: Aug 2011
Posts: 1,010
The thermistor senses the intake manifold temperature and is part of the Air Heater control. Below certain temperatures and engine rpms, the air heater grids are energized to pre-heat the intake air, reducing smoke and allowing the engine to run smoothly.

In warmer climates, these are often disabled or even removed because the heaters create a heavy load on the alternators, and are thought by some to shorten their lives.

Here is a schematic for your reference.
Attached Thumbnails
pxqzy087o417q27ksokw6gzsfg75b6br.jpg  
__________________

__________________
Larry
M/V Pelago
LarryM is offline   Reply With Quote
Old 06-28-2017, 08:39 PM   #3
Guru
 
kthoennes's Avatar
 
City: Sioux Falls, South Dakota
Vessel Name: Xanadu
Vessel Model: Mainship 37 Motor Yacht
Join Date: Oct 2013
Posts: 1,492
Rats, I thought this was going to be a thread about the thermistor in the refrigerator. Our freezer is colder than Fairbanks in January but the fridge below is lukewarm. An RV'er told me that's a classic thermistor issue. I open the doors though and can't find anything that looks like a thermistor, just a thick black wire on a freezer shelf.
kthoennes is offline   Reply With Quote
Old 06-28-2017, 09:50 PM   #4
Guru
 
Xsbank's Avatar
 
City: Pender Harbour, BC
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,797
Warning - thread drift!

Thermostat maybe, but thermistor? Naaah.
__________________
Don't believe everything that you think.
Xsbank is offline   Reply With Quote
Old 06-28-2017, 10:05 PM   #5
Guru
 
C lectric's Avatar
 
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 3,455
Actually some rv fridges use a thermister as the sensor. It is often run on the top shelf OR to the cooling fins .
That thin black wire is the thermister. They also have to be located in the right place. Maybe it has fallen or otherwise moved from the original location.
C lectric is offline   Reply With Quote
Old 06-28-2017, 11:14 PM   #6
Guru
 
Xsbank's Avatar
 
City: Pender Harbour, BC
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,797
Poop! None of my fridges have had thermistors therefore nobody has a fridge with a thermistor...isn't that how it works?

Rats. I guess I'll go watch Netflix - good night boaters!
__________________
Don't believe everything that you think.
Xsbank is offline   Reply With Quote
Old 06-29-2017, 12:18 AM   #7
Guru
 
City: Melbourne, FL
Join Date: Dec 2014
Posts: 1,690
A thermistor is simply a resistor that changes the resistance based on the temperature.

Many fluke and other VOM's include a thermistor mode where it turns the VOM into a temp sensor by converting the resistance into degrees temperature.

It often looks like a wire, or actually two wires, since you need a completed circuit. On an engine, a thermistor can have one wire since the block is the ground and the other half of the circuit.

In the fridge, it will probably have a jacketed wire with two conductors that will go back to the temp controller.

If the fridge "black wire" is very stiff and does not appear to be insulated, it is probably an old style capillary sensor that goes back to a thermostat. Those cannot be kinked or it will seal off the capillary and stop the pressure from getting from the sensing tip back to the thermostat. Here is an example of the fridge one...

https://www.zoro.com/ranco-refrigera...Q&gclsrc=aw.ds
stubones99 is offline   Reply With Quote
Old 06-29-2017, 07:01 AM   #8
Guru
 
High Wire's Avatar
 
City: Cape May, NJ and Englewood, FL
Vessel Name: Irish Lady
Vessel Model: Monk 36
Join Date: Dec 2007
Posts: 3,918
Quote:
Originally Posted by LarryM View Post
The thermistor senses the intake manifold temperature and is part of the Air Heater control. Below certain temperatures and engine rpms, the air heater grids are energized to pre-heat the intake air, reducing smoke and allowing the engine to run smoothly.

In warmer climates, these are often disabled or even removed because the heaters create a heavy load on the alternators, and are thought by some to shorten their lives.

Here is a schematic for your reference.
Interesting that there are 2 seperate heater circuits.
__________________

High Wire is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program





All times are GMT -5. The time now is 06:44 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×