Thread Tools Display Modes
Old 12-26-2007, 08:22 AM   #1
Max Simmons's Avatar
City: Everett, WA
Vessel Model: Ocean Alexander 38'
Join Date: Oct 2007
Posts: 555
Erratic Temperature Gauge

Our*starboard temp. gauges (both upper and lower) *have been problematic ovet the last 2 years.* Once the engine reaches operating temp., around 185-190, the guage will register there for a short time and them steadily climb all the way past 220, where it will stay until we shut it down.* Using a infared temp. tester, we determined the engine was not actually overheating.* I replaced the temp. sending unit and same problem.* I also switched the leads from starboard to port and got normal reading on the port gauges.* Any suggestions on how I can test the starboard gauge to determine if it is faulty?* Possibly a short?* Anyone else ever have this issue?

Max Simmons is offline   Reply With Quote
Old 12-26-2007, 12:00 PM   #2
Scraping Paint
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Erratic Temperature Gauge

>"Any suggestions on how I can test the starboard gauge to determine if it is faulty? "

It sounds like you just did. If you fed the signal from the starboard sensor to the port gauge and got a normal reading then it would seem to me that the starboard gauge is faulty. I don't know what kind of gauges your boat is fitted with but most boats, particularly older ones, have pretty inexpensive gauges. If they go south it's generally not worth trying to fix them---- it's much easier to simply replace them.

I have not had the problem you describe with our boat, but I have with a vehicle. If the temperature exceeds a certain amount, as when going up a grade, the temp gauge will sometimes climb to its maximum reading.* A whack on the gauge brings it back down to the proper reading.* In this case (a 1973 Land Rover), the problem is apparently an iffy instrument voltage stabilizer. In the Land Rover, this is a separate little component that's mounted to one of the instruments in the panel. I have no idea if boat instruments use a separate voltage stabilizer for the instruments, if each instrument has its own stabilizer built-in, or if voltage stabilizers are even used at all.

In any case, since none of your other instruments seem to be affected, I would think replacement or your one bad gauge would be your best solution.

-- Edited by Marin at 15:06, 2007-12-26

Marin is offline   Reply With Quote
Old 12-26-2007, 09:17 PM   #3
Senior Member
Chris Foster's Avatar
City: Anacortes, WA
Country: USA
Vessel Name: Juz-B-Cuz
Vessel Model: 38' Rawson Trawler
Join Date: Oct 2007
Posts: 278
Erratic Temperature Gauge

Hmmm.. electrical in a 1973 Land Rover.

Sounds like Lucas - Prince of Darkness...
Chris Foster is offline   Reply With Quote
Old 12-26-2007, 11:47 PM   #4
Scraping Paint
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Erratic Temperature Gauge

I have owned two British vehicles since new--- the 1973 Land Rover and a 1991 Range Rover. Other than the intermittent instrument voltage stabilizer problem, I have had zero problems with the electrical system in the Land Rover in the last 34 years. The only electrical components in the Range Rover that have given any trouble so far were made in Germany by Siemens. Go figure......
Marin is offline   Reply With Quote
Old 12-27-2007, 08:15 AM   #5
2bucks's Avatar
Join Date: Oct 2007
Posts: 698
Erratic Temperature Gauge

Just a shot in the dark on this, but in my experience a short is a quick one time abnormal movement. A bad ground is the slow moving, dim light, sometimes it does it sometimes it doesn't problem.

If it were me I'd loosen the mounting nuts on the guage, wiggle it around a little to scrape a clean surface, then retighten and see if that makes it all better. Changing the wires to the other guage and it then working properly tells you the problem is the particular guage. Working OK sometimes and not others says there is a variable in the mix.

Do you notice that it goes off scale when the cabin gets warmed up? That could be the guage expanding a little and losing it's only little spot that it is grounding in. Could it be that it acts up only after you turn on another item? Are they grounded together causing the problem?

Guages that act up only when warm can be "simulated" with a hair dryer to warm them up and cause the fault without running for 1/2 hour or whatever. Just let the engine run in the slip, in gear will bring the temp up faster, but in either case use the hairdryer to heat up the guage and see if you can't make it peg even before the engine is warm.

Ken Buck
2bucks is offline   Reply With Quote

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
fuel gauge marlin Other Trawler Systems 57 12-07-2012 02:35 AM
Fuel Temperature skipperdude General Discussion 4 12-23-2011 10:25 PM
Temp. Gauge (again) Max Simmons Electrical and Electronics & Navigation 3 07-24-2011 03:35 AM
Small Change in Operating Temperature Doc Power Systems 9 12-07-2010 03:58 AM
Oil gauge Fotoman General Discussion 11 09-05-2010 06:02 AM

All times are GMT -5. The time now is 01:00 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012