Ausmini
It is currently Sat Jul 19, 2025 3:43 am

All times are UTC + 10 hours




Post new topic Reply to topic  [ 24 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Tue Jul 25, 2017 5:46 pm 
Offline
1275cc
1275cc
User avatar

Joined: Fri May 02, 2008 3:07 pm
Posts: 5123
Location: The Internet
I want to lower the needle position on my temp gauge.

My question - Is there a way to adjust these gauges? If not then I was going to pull the needle off and reposition it.

My normal running temp is 85-90 deg using an infrared thermometer but needle sits just under the red on the gauge. I want it to sit halfway.

The gauge is getting a good steady 10.5v. The sender is the new MKO recommended type. No thread tape used. Good wires and earths. Its been like this for 15 years. Image


Top
 Profile  
 
PostPosted: Tue Jul 25, 2017 6:24 pm 
Offline
Yay For Hay!
User avatar

Joined: Wed Sep 08, 2004 9:27 pm
Posts: 15912
Location: Wodonga - Vic/NSW border
the 10.5v might be the problem... it's meant to be 10.0v, though it ought to be easy to adjust by adding resistance inline with the sender. The resistance decreases with temperature, so adding resistance will lower the gauge

Measure the resistance of the sender at the temperature where the needle sits where you want it, measure it at the temperature where it sits now, and add a resistor that equals the difference (sounds right, I think...)

_________________
did I tell you that I won a trophy?


Top
 Profile  
 
PostPosted: Tue Jul 25, 2017 11:39 pm 
Offline
1098cc
1098cc

Joined: Wed Nov 24, 2004 10:23 am
Posts: 1489
Location: Armidale, NSW
I've just been through a similar problem, my voltage reg is at 10.17V, we are working to sort the gauge, sender and voltage regulator in the meantime I've got a trimpot so I can adjust the resistance to make the gauge sit where you want or as it should, measure the resistance on trimpot and buy a resistor to match.
Info I got from Howard's is on my gauge 50C is 240ohms 140C is 19 ohms, you could use the trimpot with these resistances set to see if the gauge is reading correctly.

_________________
---
Roads need more corners
A Deluxe(CG13DE), 2 Clubbies(998 and 1275) and 2 Morris 1100Ss


Top
 Profile  
 
PostPosted: Tue Jul 25, 2017 11:42 pm 
Offline
1275cc
1275cc
User avatar

Joined: Fri May 02, 2008 3:07 pm
Posts: 5123
Location: The Internet
simon k wrote:
the 10.5v might be the problem... it's meant to be 10.0v, though it ought to be easy to adjust by adding resistance inline with the sender. The resistance decreases with temperature, so adding resistance will lower the gauge

Measure the resistance of the sender at the temperature where the needle sits where you want it, measure it at the temperature where it sits now, and add a resistor that equals the difference (sounds right, I think...)

It may be 10v. I was using my old analogue meter and it reads 10.5v - 0v -10.5v. I probably should check and adjust my analogue meter against my digital one first. Maybe a Wombat electronic stabilizer is on the cards.

Have you done any gauge adjustments in the past?


Top
 Profile  
 
PostPosted: Tue Jul 25, 2017 11:47 pm 
Offline
1098cc
1098cc

Joined: Wed Nov 24, 2004 10:23 am
Posts: 1489
Location: Armidale, NSW
No but as a temporary measure I have my current one reading accurately adding about 38 ohms getting a resistor tomorrow.

_________________
---
Roads need more corners
A Deluxe(CG13DE), 2 Clubbies(998 and 1275) and 2 Morris 1100Ss


Top
 Profile  
 
PostPosted: Wed Jul 26, 2017 12:20 am 
Offline
1275cc
1275cc
User avatar

Joined: Fri May 02, 2008 3:07 pm
Posts: 5123
Location: The Internet
fuzzy-hair-man wrote:
I've just been through a similar problem, my voltage reg is at 10.17V, we are working to sort the gauge, sender and voltage regulator in the meantime I've got a trimpot so I can adjust the resistance to make the gauge sit where you want or as it should, measure the resistance on trimpot and buy a resistor to match.
Info I got from Howard's is on my gauge 50C is 240ohms 140C is 19 ohms, you could use the trimpot with these resistances set to see if the gauge is reading correctly.


Thanks for that info.

My gauge has always read high and it was hard to see the temperature when you are going for a decent fang and you have to look across and workout if it's in the red or above the red. If the needle was in the middle for normal running then it would be a lot easier to see a temperature spike.

I haven't taken any ohms readings of the new sender yet at different temps. I just put it in and hoped that would fix it - as you do.

The only thing I have done with these temp gauges before is to take the glass off to clean them. I was hoping it is like a speedo where you can pull the needle off and reposition it.

Just seeing if anyone has done this before I go braking mine.


Top
 Profile  
 
PostPosted: Wed Jul 26, 2017 12:48 am 
Offline
998cc
998cc
User avatar

Joined: Thu May 18, 2006 4:57 am
Posts: 515
Location: Hamburg, Germany
all my old Smith temp gauges have small adjusters at the back, sometimes still covered with a plug of cork.
never did it myself but read that you connect it to power and a specific resistor (same value as your sensor at the temperatur your are adjusting for) and carefully adjust until it shows what it should.

_________________
Rover 214 atm ....


Top
 Profile  
 
PostPosted: Wed Jul 26, 2017 1:01 am 
Offline
1275cc
1275cc
User avatar

Joined: Fri May 02, 2008 3:07 pm
Posts: 5123
Location: The Internet
KLAS wrote:
all my old Smith temp gauges have small adjusters at the back, sometimes still covered with a plug of cork.
never did it myself but read that you connect it to power and a specific resistor (same value as your sensor at the temperatur your are adjusting for) and carefully adjust until it shows what it should.


Thankyou


Top
 Profile  
 
PostPosted: Wed Jul 26, 2017 8:08 am 
Offline
1360cc
1360cc
User avatar

Joined: Sun Apr 11, 2004 11:32 am
Posts: 12390
Location: Sthrn HiLoLands, NSW, Australia
gtogreen1969 wrote:
I want to lower the needle position on my temp gauge.

My question - Is there a way to adjust these gauges?


Yes...you can very carefully bend the pointer/needle back and the gauge will read lower for a given input :D

[PS you can't usually "pull the needle off and reposition it" because of the way the gauge pictured is manufactured].

_________________
"Show me the Mini!"


Top
 Profile  
 
PostPosted: Wed Jul 26, 2017 8:56 am 
Offline
1275cc
1275cc
User avatar

Joined: Fri May 02, 2008 3:07 pm
Posts: 5123
Location: The Internet
9YaTaH wrote:
gtogreen1969 wrote:
I want to lower the needle position on my temp gauge.

My question - Is there a way to adjust these gauges?


Yes...you can very carefully bend the pointer/needle back and the gauge will read lower for a given input :D

[PS you can't usually "pull the needle off and reposition it" because of the way the gauge pictured is manufactured].

Thanks


Top
 Profile  
 
PostPosted: Wed Jul 26, 2017 7:12 pm 
Offline
998cc
998cc

Joined: Wed Sep 22, 2004 5:46 pm
Posts: 728
Location: Melbourne
The needle position can be adjusted. There is/are a slot/s in the back of the temp gauge to adjust the needle position.
(I can't remember if there are one or two adjustment slots in the back)
The 6 dots on the gauge face, 2 under each of the C,N and H correspond to specific water temps but I don't know what they are.
My S has the needle slightly below the N when the thermostat - 180 deg F, starts to open.
The needle centreline is above the LH edge of the N. It has been this way since new.
Are you sure you have the correct sender?
There are a multitude of different senders out there, some genuine Smiths and some aftermarket.

Hope this helps

RonR

_________________
68 build Mk1 Cooper S
72 Clubman GT project. Total restoration required


Top
 Profile  
 
PostPosted: Wed Jul 26, 2017 8:05 pm 
Offline
1275cc
1275cc
User avatar

Joined: Fri May 02, 2008 3:07 pm
Posts: 5123
Location: The Internet
miniron wrote:
The needle position can be adjusted. There is/are a slot/s in the back of the temp gauge to adjust the needle position.
(I can't remember if there are one or two adjustment slots in the back)
The 6 dots on the gauge face, 2 under each of the C,N and H correspond to specific water temps but I don't know what they are.
My S has the needle slightly below the N when the thermostat - 180 deg F, starts to open.
The needle centreline is above the LH edge of the N. It has been this way since new.
Are you sure you have the correct sender?
There are a multitude of different senders out there, some genuine Smiths and some aftermarket.

Hope this helps

RonR

I bought the sender that John at MKO recommends. My old sender was doing the same thing. This is the one I bought. https://minikingdomonline.com.au/produc ... -cooper-s/

Both old and new are the same sender marked B710.

As they sit now the one on the engine is 660 ohms @18 deg. The old one is 850 ohms @ 17 deg. To do a proper comparison i will have to take out the new one then compare the 2 using hot / boiling water.

I think i will try the adjustments on the gauge first.Image


Top
 Profile  
 
PostPosted: Wed Jul 26, 2017 8:36 pm 
Offline
1275cc
1275cc
User avatar

Joined: Fri May 02, 2008 3:07 pm
Posts: 5123
Location: The Internet
I had a bit of a google and found this guy who has tested a new GTR104 / B710. Now i have something to compare to if needed.

http://diary-of-mgb.blogspot.com.au/201 ... r.html?m=1


Top
 Profile  
 
PostPosted: Thu Jul 27, 2017 9:48 am 
Offline
998cc
998cc
User avatar

Joined: Tue Sep 06, 2005 6:20 pm
Posts: 637
Location: Melbourne
Pretty good description of how to adjust a Smiths gauge here:
http://www.mgb-stuff.org.uk/fuel.htm


Top
 Profile  
 
PostPosted: Thu Jul 27, 2017 11:20 am 
Offline
1275cc
1275cc
User avatar

Joined: Fri May 02, 2008 3:07 pm
Posts: 5123
Location: The Internet
wild_willy wrote:
Pretty good description of how to adjust a Smiths gauge here:
http://www.mgb-stuff.org.uk/fuel.htm

Thanks willy. Thats what i was chasing. Its a pitty i was out in the shed this morning and missed the post. I worked it out pretty quickly how to do it after taking mine apart. All sorted and fixed. Cheers

Here it is at 89 Deg. I could still lower it a bit but at least now the needle is away from the H mark and easier to read when glancing across.

Image

Image


Last edited by gtogreen1969 on Thu Jul 27, 2017 11:49 am, edited 3 times in total.

Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 24 posts ]  Go to page 1, 2  Next

All times are UTC + 10 hours


Who is online

Users browsing this forum: No registered users and 104 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  

© 2016 Ausmini. All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.