Modifying the temperature gauge compatible with the 2.0L

[Simon Jones]

The whole reason for wishing to increase the sensitivity of the temp gauge is to be able to see when the thermostat is working correctly and also to give you indication of when something is going wrong. By default, the standard gauge will get to a position mid way and then just sit there. If you do see it move about that point, then you're already up in the danger zone, where damage may already have been done. The temp gauge mod is a very worthwhile thing to do (in my opinion).

[Kernongo]

Cheers Simon... I agree.

Mark

[mentaliss]

The whole reason for wishing to increase the sensitivity of the temp gauge is to be able to see when the thermostat is working correctly and also to give you indication of when something is going wrong. By default, the standard gauge will get to a position mid way and then just sit there. If you do see it move about that point, then you're already up in the danger zone, where damage may already have been done. The temp gauge mod is a very worthwhile thing to do (in my opinion).

perhaps then Mazda should have employed Haydn Callow

[psquiddy]

I have a similar problem with the gauge on my 2.0 - search for "Re: Temperature gauge problem" from a couple of weeks ago. (How do I make a link to a topic anyone?)

Having swapped my diesel for a 2.0 petrol/lpg it appeared that the gauge was not working - but I had only done long runs on motorways - once I hit stop/start traffic it appeared to work - so my current thinking (thanks for the input on here) is that it is working, but the car must be running cool.

I have decided to do the gauge mod, anticipating that I will then get some sort of reading even when it is running cool, rather than reading nothing when cool, then something when hot (hope that makes sense).

[Kernongo]

I have decided to do the gauge mod, anticipating that I will then get some sort of reading even when it is running cool, rather than reading nothing when cool, then something when hot (hope that makes sense).

Hi psquiddy

... I read your thread which is what started me off thinking about the mod for my 2.0l petrol. But in the fact sheet there is a bit in the text which states that "the gauge will not start to move until the coolant temperature reaches about 75 deg C"... I've now done the mod (including bridging across the diode) & using a resistor from a well know high street electronics gadgets and components supplier rated at 2w 120ohm which admittedly is so far proving to be too high a rating (Doh..!)

The fact sheet indicates that a higher value resistor will provide gauge deflection at higher temperatures, so I am satisfied that with my error and my experimenting so far I am running cool, which matches the general opinion for the 2.0L.

stage 2 therefore is to try the listed 100ohm and my expectation is to see the needle deflection around the 30-40% level on the gauge (82 - 85 deg).... how do I get the little degree symbol..??

Regards
Mark

[g8dhe]

° - Put a shortcut of Character Map (All Programs|Accessories|System Tools) on the Quick Launch bar, then you can select/build up any string of characters, or just remember the Alt-Code for those you use most!

[Kernongo]

Yay..!!.. cheers Geoff ... p.s.. excellent spherical visions, especially Widemouth Bay, it's our favourite for hitting the surf on the body boards...

°

[Kernongo]

To update, I've now replaced the resistor with a 100ohm one and this was after warming my Bongo with a short trip.

On replacing the consol and turning the ignition on the gauge registered as I expected so all was looking good.

After sitting for a few minutes admiring a temperature reading I started the engine at which point the gauge needle dropped to rest and stayed there.

My assumption is that if the resistor has blown then this would cause the needle to shoot up (see other thread) so with a lower value resistor I am thinking the installed bridging wire across the diode has failed... To be investigated but if so I may just twist the wires on the diode to achieve the same effect as mentioned elsewhere on here.

Regards
Mark