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Oil temp on stack
Posted: Fri Jan 19, 2007 11:36 pm
by Rich H
The idea is as old as the Liz but here is a wiring diagram and
fitting guide shamelessly stolen form SELC*CK. anyone see a problem? seems quite a neat idea apart fomr the fog lamp wiring, why not use another 205 switch?

Posted: Sat Jan 20, 2007 12:50 am
by tenkfeet
Thats a clever idea , and more importantly cheap and easy.
I suppose you could put a switch to the fog light to turn it off and just flip it over if you ever need to use it anger ( I cannot remember the last time I used my fog lights). If my electrics is correct you would not have to add a resistor in the wire to the relay as the coil resistance is quite high . ( 80 ohms in the link) and only draws 1.8 watts. Correct me if I am wrong.
Posted: Sat Jan 20, 2007 8:43 am
by mac
So what does it do? Does the light come on when you exceed x-temp? or do you wiring it for cold and it goes off when it reaches operating temp?
Mac
Posted: Sat Jan 20, 2007 10:46 am
by Shug
The way I read it, the switch changes the stack display between water and oil temps. Good idea...
Posted: Sat Jan 20, 2007 12:49 pm
by mac
So when you press a button it would switch between the two?
That would be worth while if you can find a reliable place to stick the probe.
Mac
Posted: Sat Jan 20, 2007 12:59 pm
by Shug
That's the idea, although it's got a hammering on SELC*CK, with Scuffers lamenting the crap 2 wire probe used.
So, good to check you're up to temp, but not a reliable value, is the concensus.
Posted: Sat Jan 20, 2007 5:03 pm
by Rich H
What difference does accurate oil temp really make anyway? I think it would be nice to ensure that warm up is complete before a thrash or that it is still up to temp after a stop. The actual value, as long as its steady, would be irrelevant. Like the water temp, steady is good, big changes is bad... Pretty sure the stack just flashes at 120 anyway.
Its actually uses a water temp probe, we all know they are crap but they are only £8 and last around 6 months....!
I like it as it is neat and does not involve hacking the dash about or a loose gauge.
Posted: Sat Jan 20, 2007 6:40 pm
by thinfourth
Same system as used on many 7's push a button or flick a switch and you have an oil temp gauge.
Why the hell you would use a relay though to switch a sensing line i would get a tiny wee toggle switch and mount it on the plastics round the steering column.
As to accuracy i think it would be about 5 degrees plus minus would be what you would be getting. You want to know if it gets stupidly hot or when you have a big difference between water and oil as a K don't like that
Posted: Mon Jan 22, 2007 9:24 am
by Rich H
Does anyone (Robin!) know the where abouts of a supposed cat warning cable for the asian market? Could save a bit of wiring if I can find it in the loom!

Posted: Mon Jan 22, 2007 2:35 pm
by robin
Nope, sorry. I could check the wiring diagrams when I get home, or you can do the same
On most Elise K's I have seen there has been a spare cable at the oil pressure switch which presumably is there for those Rover models that fit the oil temp sender into the relevant hole on the oil pump housing (instead of the blanking plug that's currently fitted).
That cable probably only makes it back as far as the main engine loom connector, but it's at least a start.
The reason the "designers" picked the fog light was so that you could install the relay in the boot or engine bay area and thus re-use the two front-to-back wires (the coolant temp sender wire then carries both oil and water temps, the fog light wire carries the selector signal).
Of course there are more elegant solutions, but they would involve either some electronics or some cabling runs or both.
Cheers,
Robin
Posted: Mon Jan 22, 2007 3:19 pm
by Rich H
Thanks Robin, I'll check, I take it that it's in the Service Manual? Not ventured into the lekky bits, all it said when I got that far was "Here be dragons!"