Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 24-07-2010, 13:16   #16
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,085
Images: 241
Goto ➥ http://www.cruisersforum.com/forums/...sting-645.html
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is online now   Reply With Quote
Old 24-07-2010, 13:26   #17
Armchair Bucketeer
 
David_Old_Jersey's Avatar

Join Date: Oct 2006
Posts: 10,012
Images: 4
Quote:
Originally Posted by GordMay View Post
You know how to test senders & gauges, right?

http://www.cruisersforum.com/forums/...sting-645.html
no - not yet

Cheers
David_Old_Jersey is offline   Reply With Quote
Old 24-07-2010, 17:37   #18
Registered User
 
svcambria's Avatar

Join Date: Jun 2010
Location: Mexico (currently)
Boat: Panda 40 - S/V Cambria
Posts: 573
Methinks the sender must be grounded before it will work in a cup of tea.

Michael

Oops - you did ground it. Never mind...
svcambria is offline   Reply With Quote
Old 25-07-2010, 13:35   #19
Registered User
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 8,462
Any progress on this David?
DeepFrz is offline   Reply With Quote
Old 25-07-2010, 14:14   #20
֍֎֍֎֍֎֍֎֍֎

Join Date: Apr 2006
Posts: 15,136
David, yes a hot cuppa is sufficient to test a temperature sender.

The sender itself is usually a "thermistor", that is, a resistor which changes value depending on the temperature. You test it by using a plain ohm meter set on a thousand-ohm scale. One test lead goes to the outside of the sender, the threads themselves, and the other lead goes to the terminal for the wire. (Usually the senders have one wire terminal and then make ground through the engine block.)

The resistance of a typical sender is 240 ohms at room temperature, and 40 ohms in a nice cup of near-boling water. Very rough numbers--they could be half or double that, it is the variation you are concerned with.

If the sender shows a similar variation from cold to hot, it is working. Sometimes they go dead, and I've had a Volvo sender go dead only to be replaced by a new DEAD one from Volvo, so if you do replace them, test the new ones as well.

The other sneaky problem could be that someone said "Gee, that was hard to replace" and installed those senders with some teflon tape on the threads. Teflon is an insulator, if the sender has to be grounded through the block--teflon will insulate it and you'll never get it to work. This must be a metal-to-metal contact on the threads. Antiseize is OK, teflon tape is not.

Since the temp meters peg when you ground the sensing wire directly to the block--the meters and all the wiring are OK, and the problem is in the senders. Could be one went dead, then the other, and over the past decade a PO just ignored them because Volvo parts can be, well, dear.
hellosailor is offline   Reply With Quote
Old 25-07-2010, 14:46   #21
Armchair Bucketeer
 
David_Old_Jersey's Avatar

Join Date: Oct 2006
Posts: 10,012
Images: 4
Quote:
Originally Posted by DeepFrz View Post
Any progress on this David?
Nope. It's Sunday Only discussions with Father (and he offers his thanks to all on the internet - however that works ).

Tommorow me Father will take the sender to the Marine Engineers / Volvo Dealer and get them to test - have a chat (he's known the boss for 20 odd years) - and unless they come up with any other plan probably order a new one............and keep fingers crossed that the problem is simply the temp sender. (why 2 at the same time? engines not used much over the last couple of years? maybe also they went a few months apart and as engines not used not noticed?)

BTW engines are 13 years old - father got them installed brand new (boat now 30 yo) and does his own routine maintanence / basic spanner work - but has thrown a mechanic at the engines on a couple of occassions over the years for a few things, albeit nothing major. Condition wise they look under 6 months old .........hopefully insides look the same............

David_Old_Jersey is offline   Reply With Quote
Old 25-07-2010, 15:06   #22
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,085
Images: 241
Quote:
Originally Posted by hellosailor View Post
... The resistance of a typical sender is 240 ohms at room temperature, and 40 ohms in a nice cup of near-boling water. Very rough numbers--they could be half or double that, it is the variation you are concerned with...
More or less ...
Attached Thumbnails
Click image for larger version

Name:	79gaugetest3-med.jpg
Views:	207
Size:	189.9 KB
ID:	17963  
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is online now   Reply With Quote
Old 25-07-2010, 15:29   #23
Armchair Bucketeer
 
David_Old_Jersey's Avatar

Join Date: Oct 2006
Posts: 10,012
Images: 4
Quote:
Originally Posted by GordMay View Post
More or less ...
Unfortunately the circuit tester is very basic. Power on. power off.

Now it's off, the Engineer can bench test. Over (in?) a cuppa

Will let folks know on progress...........
David_Old_Jersey is offline   Reply With Quote
Old 01-08-2010, 11:56   #24
Armchair Bucketeer
 
David_Old_Jersey's Avatar

Join Date: Oct 2006
Posts: 10,012
Images: 4
Quote:
Originally Posted by David_Old_Jersey View Post

Will let folks know on progress...........
Long story short

Temperature Sender was taken to Marine Engineers - tested it. said ok

Father said: Hmmmm..........I'll order 2 new ones please (£26 / USD40 for both.......figured that cheap and easy enough to fit into the category of might as well try even if a longshot - that money wouldn't get the Engineer half way to the boat, let alone tools out ).

Fitted both new Senders, fired the engines up - and the guages now work

Today took her for a run around the coast for 3 hours to her summer mooring and all ok

BTW just for general info, both (Volvo) engines have 772 hours on them, from new in 13 years - I guess the temp senders failed from old age rather than wore out But to be fair that includes well north to Paris and south to the Bay Biscay over that period. and a couple of years along the way of doing b#gger all

Father sends his thanks to all on the internet - he is now even thinking of joining the internet age himself. that's gonna be painful (for me)
David_Old_Jersey is offline   Reply With Quote
Old 01-08-2010, 13:45   #25
֍֎֍֎֍֎֍֎֍֎

Join Date: Apr 2006
Posts: 15,136
Gord, it is interesting to see that EU senders are backwards from US ones. FWIW in my experience the Japanese ones follow US convention. Either way...

David, I'd suggest you fire up the old word processor and get some "certificate borders" at a stationery store. Then send each of those alleged engineers a large "Notice Of Revocation Of Engineering Credentials" signed date sealed stamped and made up in a suitably official manner.

Sometimes I wonder if the entire world has gone incompetent, or it they really ARE on a mission to waste everyone else's time.

What can you say, they're Volvo parts, they probably got homesick and then, when they heard that Volvo was bought out by the Chinese, died of despair.
hellosailor is offline   Reply With Quote
Old 01-08-2010, 14:22   #26
Registered User
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 8,462
Quote:
Originally Posted by DeepFrz
I really doubt that both thermostats or temp. senders would go bad at the same time. Possible, but not likely. Is there anything in common on the instrument panel connecting the two gauges? If you can find out what the full scale deflection voltage is and then feed some voltage to the gauges, do they work? Its a lot easier to check them than it is to pull 2 thermostats.

My first guess is that the gauges have a common voltage source.
Munch, munch, munch....yechhhh
DeepFrz is offline   Reply With Quote
Old 01-08-2010, 15:10   #27
Armchair Bucketeer
 
David_Old_Jersey's Avatar

Join Date: Oct 2006
Posts: 10,012
Images: 4
Quote:
Originally Posted by DeepFrz View Post
Munch, munch, munch....yechhhh
The next step was going to be back to the wiring up to the guages - as both senders going pop at same time did sound unlikely, but I guess they really went a few months apart (could even have been longer)

Went for £26 of senders as easier to DIY than chasing electrickery through spaghetti behind the dashboard

All ideas were greatly appreciated to help us muddle through / get a feel for being in the ballpark of the right track.

Double bonus on the mechanical front this week - the Triumph lives! 900cc of triple
David_Old_Jersey is offline   Reply With Quote
Old 01-08-2010, 15:30   #28
Registered User
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 8,462
Glad it worked out.

I once saw a Triumph with flames shooting out the vent hole in the gas tank cap and going at least 20' in the air. We had just come back from a trip to Ontario and my friend overfilled the tank and didn't clean up enough before he started the beast. The poor guy had just bought it from his brother a few weeks earlier.
DeepFrz is offline   Reply With Quote
Old 15-04-2012, 22:51   #29
Registered User

Join Date: Apr 2012
Posts: 4
Re: Volvo MD22 - errr, Where's the Thermostat ? :-)

I have red this topic with big interest, because I have quite a similar problem on my MD22L.
I have no temperature gauge, only the standard panel.
Problem: when the engine is started a few instants later (max. 1 minute) the temperature alarm is activated.
Actions done up to now:
checked temperatures with infrared thermometer (all OK!)
replaced the temperature switch (9) and the temperature sending unit (6) with new (expensive) volvo ones.
Suggestion of the volvo engineer: replace the complete electronic print
(costs 250 to 300 Euro) but no guaranties if it will eliminate the false alarm.
The alarm test on the panel works fine and I can switch off the soundbeep after starting, but the temperature alarm light stays flashing and what is the worst that I am not well informed if a real problem with engine temperature should occur.
Anybody with same experiences or suggestions to help me?
Looking forward to reactions
Wavelength is offline   Reply With Quote
Old 16-04-2012, 09:29   #30
֍֎֍֎֍֎֍֎֍֎

Join Date: Apr 2006
Posts: 15,136
Re: Volvo MD22 - errr, Where's the Thermostat ? :-)

Wavelength, no specific ideas but if that "electronic print" is the usual, a strip of flexible plastic with printed circuit traces on it? And no components, just printed "wires" ?

Those are routinely repaired, no reason to replace them. If you can access it, or unplug it (carefully, sometimes the connectors are subtle and difficult to align), by all means take it out for a better examination. There's no magic there, just metallic traces that basically are wires. Either they are broken or unbroken, and if they are broken, you can carefully solder a jumper across them, or to bypass them. NOT a big deal, unless you are a mechanic charging $125/hour and don't want to invest an hour of your time.

I'd suggest getting a factory manual, or at least the circuit diagram, which would at least allow you to follow the circuit and see what might be tripping the alarm. Throwing random and expensive oarts at it often won't fix anything--like a simple short or broken wire someplace.
hellosailor is offline   Reply With Quote
Reply

Tags
volvo

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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
Thermostat Captin_Kirk Engines and Propulsion Systems 2 19-04-2010 07:25
Perkins Prima / Volvo MD22 Timing Aegean sailor Engines and Propulsion Systems 4 25-03-2010 20:17
WTB Volvo MD7B Thermostat Housing Morning Glory Classifieds Archive 0 14-11-2009 22:08
Engine Oil Quantity & Grade for MD22 P sybobcat Engines and Propulsion Systems 8 03-08-2009 05:04
Thermostat Needed? Milton Bertin Engines and Propulsion Systems 11 17-07-2009 06:54

Advertise Here


All times are GMT -7. The time now is 04:34.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.