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Modified Temperature Gauge reading
Posted: Sat Oct 05, 2013 10:46 pm
by cmm303
I have just modified my temperature gauge. I chose to put 110 ohms across the terminals so I should be getting a slightly lower temp. reading than if I had opted to use 100 ohms. I took BertieB out for a 30km run. Generally the gauge sat just above half way mark. Going up a long steep hill, country lane so not fast but with revs about 3k evenutally the temp got to about 80%. As soon as the gradient eased off it dropped back down within a minute or two, and on the downhill the other side it dropped below half way.
Before modifying the gauge I knew nothing of BertieB's hot flushes

but wonder whether he needs a doctor or not.

Re: Modified Temperature Gauge reading
Posted: Sat Oct 05, 2013 11:11 pm
by Northern Bongolow
mine has the same mod, and does about the same----------------sounds fine to me

Re: Modified Temperature Gauge reading
Posted: Sun Oct 06, 2013 8:24 am
by cmm303
Re: Modified Temperature Gauge reading
Posted: Sun Oct 06, 2013 8:33 am
by Driver+Passengers
Mine does the same... also, if I flick the hold button on (drop a gear) while going up a hill, the temperature doesn't rise as much - because revs are higher, the water pump circulates coolant from the engine to the radiator faster, I think. Have a play.

Re: Modified Temperature Gauge reading
Posted: Sun Oct 06, 2013 11:33 am
by g8dhe
Likewise even on a V6 engine.
Re: Modified Temperature Gauge reading
Posted: Sun Oct 06, 2013 1:04 pm
by mikeWalsall
Following some advise ..when I modded my temp. gauge I only fitted the resister .. I did not bridge the wire ..
Now when I turn the ignition on the gauge goes up to around one third .. then sits there never moving even after a 'fast' 200 mile journey ..
Re: Modified Temperature Gauge reading
Posted: Mon Oct 07, 2013 8:37 am
by haydn callow
mikeWalsall wrote:Following some advise ..when I modded my temp. gauge I only fitted the resister .. I did not bridge the wire ..
Now when I turn the ignition on the gauge goes up to around one third .. then sits there never moving even after a 'fast' 200 mile journey ..
Why?? What does it tell you now and more to the point what will it do if the temp rises......I would think it would be better as standard.
Re: Modified Temperature Gauge reading
Posted: Mon Oct 07, 2013 10:36 am
by mikeWalsall
To be honest with just the resister the gauge it does not seem to be fluctuate up or down ..
Reading the fact sheet on doing the mod....
http://www.enginesaver.com.au/Tempgauge.pdfit
... it says to fit an 100ohm resister .. and .. bridge the two wires on the front of the gauge ..
Then some Forum posts said just fit the resister and it would be sufficient / efficient .. so I took this easier route ..!!
Re: Modified Temperature Gauge reading
Posted: Mon Oct 07, 2013 10:42 am
by haydn callow
I think it would be a good thing to do the bypass 'short out' mod....Then your gauge will start telling you things.
Re: Modified Temperature Gauge reading
Posted: Mon Oct 07, 2013 2:39 pm
by g8dhe
Fully agree with Haydn, just changing the resistor will have little affect other than just shifting the normal position a little. I just twisted the Zener diode leads together to short out the diode, the needle will then move without any "pause" in the temperature and the resistor chosen will then adjust the "normal" position to your liking.
Re: Modified Temperature Gauge reading
Posted: Mon Oct 07, 2013 11:12 pm
by the1andonly
Iv'e modified mine with a 100ohm res from maplin as mike w with add mod. It runs on the warm side (2/3 scale) as normal.
when towing uphill (serious hill 1st gear North wales 4 hr trip) it frightened the sh1t out of me hitting the H but at top on going downhill soon temp went down with no load. This is too frightening for me, 110/120 ohm maybe more appropriate.
but at least you can see a change.
or have I got a problem?
Re: Modified Temperature Gauge reading
Posted: Tue Oct 08, 2013 12:24 am
by teenmal
the1andonly wrote:Iv'e modified mine with a 100ohm res from maplin as mike w with add mod. It runs on the warm side (2/3 scale) as normal.
when towing uphill (serious hill 1st gear North wales 4 hr trip) it frightened the sh1t out of me hitting the H but at top on going downhill soon temp went down with no load. This is too frightening for me, 110/120 ohm maybe more appropriate.
but at least you can see a change.
or have I got a problem?
This is exactly why these gauges were restricted.
Re: Modified Temperature Gauge reading
Posted: Wed Oct 09, 2013 1:30 pm
by cmm303
the1andonly wrote:Iv'e modified mine with a 100ohm res from maplin as mike w with add mod. It runs on the warm side (2/3 scale) as normal.
when towing uphill (serious hill 1st gear North wales 4 hr trip) it frightened the sh1t out of me hitting the H but at top on going downhill soon temp went down with no load. This is too frightening for me, 110/120 ohm maybe more appropriate.
but at least you can see a change.
or have I got a problem?
exactly my experience but more extreme - my loading was less onerous and have 110 ohm resistor. Hence my post. Love to know the point at which to bail!! Could be relevant for Scotland.
Re: Modified Temperature Gauge reading
Posted: Wed Oct 09, 2013 1:42 pm
by Simon Jones
The temp gauge (modified or not) just gives you a relative indication of engine temperature. If you want to know when 'hot' is 'too hot' then you'll need a digital display like TM2 / TM4 or even a cheap joby from ebay. While there is no hard and fast temperatures that the engine should normally run at, with an actual read-out you will get to know what the typical values are for your vehicle.