10 replies to this topic

[miniman86]

hi, dont know if anyone can help, ive got a custom dash for my mini and ive been told the gauges (fuel, temp, amps, volts) need to be run off 9 volts through a bi-metallic strip? i think i know what one of these is but i dont know where to get one or how to wire it up. any help is much appreciated. cheers, alex

[Dan]

A voltage regulator. It doesn't have to be a mechanoelectric bi-metalic spring version, it can be a chip so long as it produces the right output. What make are the guages? DK Lawson knows what chips to use.

Amps and volts don't need regulated voltage, only temp and fuel. In fact I'd dump the ammeter if I were you and fit a guage that's more useful and less dangerous to wire up.

[miniman86]

ok cheers, the gauges are out of a dolomite sprint, and are smiths. how come the ammeter is dangerous then?

[Dan]

If they're Smiths then they need 10v not 9. Aftermarket gauge Smiths voltage stabilisers are readily available from Mini specialists. Not all OE Smiths gauges need the same input from their senders, it is possible these will read wrong using Mini sender units. Not so much a problem for the temp gauge as you can fit a different sender but a real issue with the fuel level.

This ammeter is probably a -30+30 if it's from a Dolomite, if so then the first time you fire up an engine fitted with an alternator and run 40 or 50 amps through it it'll burn out. When you have an ammeter fitted, all the power running through your car (except the starter, very important) has to run through the wires fitted to the back of it and through the gauge itself. That means that when the gauge fails you have no electrics at all. It is fairly easy to wire up but having all the power running through two large unfused cables like that is an invitation to disaster. And they don't really provide much usefull information. Having said that I would fit one myself if I were doing the dash again but only if I could track down one of the remote sensing types so that all the high power cables remain in the engine bay or if I could design an intrinsically safe way of wiring it. It would be a -60+60 though in order to cope with an alternator.

Edited by Dan, 25 July 2006 - 01:43 PM.

[miniman86]

ok cheers, i think the fuel gauge is out of a dolomite anyway! is there any way of making it work? i bought a custom made dash off someone and it had that in it, so thats why i want to use it!

minispares do a voltage stabilizer for £14.10 including vat, think thats the one!!

[dklawson]

14 GBP for a stabilizer? And I thought we got raped over here when it came to parts prices.

Download my PDF at:
http://home.mindspri...eStabilizer.pdf

The PDF will show you how to calibrate old stabilizers and build solid-state versions to replace them. The chips you need are identified in that document. Succinctly, the simple solution is to buy a u7810 chip in a TO-220 case size, solder leads to it (and insulate them with heat shrink or tape), and mount it to an earth ground behind the dash. 14 GBP... NOT, how about 50p.

Dan has filled you in on all the other information. 10 v to the Smiths gauges. The fuel gauge should be OK as I think later Triumphs used the same 20-240 ohm (full to empty) range as the Mini did. It will be easy to confirm this on the bench. Since you know the temp gauge came out of a Dolomite, buy a NEW sender for a Dolomite and use it with your gauge. Don't bother trying to get an old, used, Mini temperature sender to work, it won't be worth the effort.

[Tomf]

IS it true that because i have a single centre clock i should have a voltage stabilizer fitted and i should he able to run a feed from it. If so do you know whick wires that are running on 10v

[miniman86]

someone correct me if im wrong but i think the central clock already has them built in? cheers dklawson!!

[Tomf]

I just looked behind my centre clock and there is a voltage stabilizer already there

[dklawson]

The stabilizer was added in late 1964. Until much later when it was integrated into the instrument circuit board, the stabilizer appeared as a small rectangular container bolted to the top, back of the center mounted speedometers.

The stabilizer has three electrical connections. The first is the metal case which must have a good clean earth connection. If you don't provide a good earth the stabilizer passes full 12V and your gauges will read high. When you examine the insulator board with the spade lugs on it you will find one connection with spade lugs labeled "B". The "B" terminal goes to the Battery (via switched power/fuses). The third terminal will be labeled "I" and it is the Instrument connection. That's the one that runs at 10V.

[miniman86]

thanks for your help, ill have to get one and make a start!