Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > Troubleshooting

Reply
 
Thread Tools Display Modes
  #1   IP: 156.57.175.211
Old 07-30-2018, 05:54 AM
Joe Miller Joe Miller is offline
Senior Member
 
Join Date: Jun 2018
Posts: 25
Thanks: 0
Thanked 3 Times in 3 Posts
temp gauge

Hello All,

While running my engine I notice the temp. gauge is pegged at maximum.
Is there an easy way to test gauge with a multi meter or other method.
Could it be a ground issue?

I have a second gauge and sender I could remove from my parts engine,
but would like to check original before I do a switch.

one note, I have only run engine from marina launch area to the mooring field, a 5 minute motor and 20 minutes charging batteries.

Thanks,

Joe

Last edited by Administrator; 07-30-2018 at 08:54 AM.
Reply With Quote
  #2   IP: 174.192.5.15
Old 07-30-2018, 08:03 AM
tac tac is online now
Senior Member
 
Join Date: Nov 2015
Location: Harpswell, Maine
Posts: 209
Thanks: 11
Thanked 80 Times in 56 Posts
Gauge Sender Testing

You haven’t said which manufacturer. Most (?) A4 OEM gauges were Stewart Warner. These references should help. A search of this forum should give you plenty of past discussions.

http://forum.chaparralboats.com/inde...stance-values/

https://www.stewartwarnercanada.com/...ic%20Gauge.pdf

https://www.stewartwarnercanada.com/...l%20gauges.PDF

https://www.jamestowndistributors.co...t.do?docId=842
Reply With Quote
  #3   IP: 24.152.132.140
Old 07-30-2018, 09:13 AM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
In this order:
  1. Take temperature measurements with an infrared temp gun (cheap at Harbor Freight Tools) to be certain you're not actually overheating.
  2. Disconnect the wire from the temp sender to see if the gauge zero's. If it does, that indicates a possible sender fault. If it doesn't, move to test #3.
  3. Remove the sender wire from the gauge S terminal to see if the gauge zero's. If it does, a sender wire short to ground is indicated. If it doesn't, the gauge is faulty.

Here's a Tech Tip from Don Moyer:

How can I determine if my sending unit or gauge is causing a faulty (or no) reading in the cockpit?

1) Check the connections at both ends of the sensing wire (between the sensor and the cockpit gauge) as well as the positive terminal on the gauge to be sure the gauge is receiving 12 volts. Be sure to check for a good connection from the grounding terminal on the gauge to "engine" ground. Stewart Warner gauges (perhaps others as well) need to be grounded directly to the engine for the gauge to work. If your wiring bundle disappears (like under the cabin sole) on the way to the cockpit and cannot be inspected, we recommend running a single cheap temporary wire directly from the sending unit to the gauge for a quick check of the circuit.

2) After insuring that all connections are sound, you can remove the wire from the sensor and touch it to the head (essentially grounding it to “engine ground”). With the sensing wire grounded to the head, a gauge will usually move to one side of the gauge or the other. If the gauge still shows no movement, the gauge is probably defective.

3) You can make a simple functional check of the sending unit by checking the ohms (resistance) between the terminal of the sending unit and ground when the engine is cold, and then look for a change in the resistance as the engine warms. While each company uses a somewhat different recipe in terms of resistance versus particular readings on the gauge; in most cases, if the resistance in a sending unit is varying with temperature, it's probably working OK. Sending units tend to either work reliably, or not at all.

4) After insuring that the sending unit is functional, and that all circuits to the gauge are proper, the gauge still shows no reaction (or an obviously improper reading), it's probably time to replace the gauge. When replacing a gauge, it's usually necessary to replace the sending unit as well as the gauge since all manufactures use different specifications in terms of resistance versus gauge reading. You can try replacing the gauge with one by the same manufacturer in hopes that the sending unit will be compatible, but if the gauge and sending unit are quite old, the sending unit might still not be compatible with the new gauge.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others

Last edited by ndutton; 07-30-2018 at 10:32 AM.
Reply With Quote
Reply

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Water Temp vs: Head Temp Al Schober Cooling System 8 11-25-2016 10:03 AM
How does the temp guage work? Rbyham General Maintenance 12 07-18-2014 01:57 PM
Free Temp Guage marthur For Sale - Engines and Engine Parts 1 08-22-2012 07:41 PM
temp guage "wacky" surfjat Cooling System 10 06-04-2012 03:11 PM
water temp guage on a '62 A-4 JimH Troubleshooting 1 04-04-2007 06:30 AM


All times are GMT -4. The time now is 09:31 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved