Instrument Regulator Quick Fix

 
I recently replaced the innards of the voltage stabilizer in my series Va Super Snipe with a semiconductor which will regulate the voltage to the required 10v. The semiconductor fits inside the old regulator box, so if you look   behind the dash you can't spot the difference!   

The stabilizer is the same for the series IV onwards Super Snipes. In the Snipe it lives behind the dash between the clock and the glove box. It has two terminals - input and output and the body is earthed. From the wiring loom the green leads go to the input (about 12 volts) and the green/yellow leads send 10 volts to the fuel gauge and temp gauge. The black earth lead is attached by the screw that holds the regulator to the back of the dash. All you have to do to get it out is take the speaker grill off, reach in and pull the leads off and undo the screw holding it to the back of the dash. 

The stabilizer cover was held on by a rivet at each end. I drilled these out and have replaced them with bolts (picture 1). Inside was a bi-metallic strip and wire which, as I understand it, regulates the voltage by heating up and bending  when the voltage is too high, thereby breaking the circuit until the strip cools down. I cut the strip off, put the semiconductor in its place and soldered it to each corresponding terminal. It is conveniently just the right size and shape (picture 2) to fit in the box.. As you can see, I am a novice with the soldering iron - any idiot can make a mess like that (picture three).

When putting it back together, note that the terminals are labeled "B" for battery and "I" for instrument, so don't make the mistake of thinking (sensibly) that "I" might stand for "input"!

In my experience, if you ask at most standard electronics suppliers they will tell you that nobody makes a 10 volt regulator. I've got one, so this is obviously not correct - I can't rightly remember, but I think I bought the regulator from Attspeed Auto Instruments in Sydney (Australia) (02) 9833 0055, but it might have been Autoprobe (02) 9791 0588. The hieroglyphics in picture three might help you find someone that sells the semiconductor. It says: ITT  TCA   700Y. One supplier I’ve found on the web is at:  http://www.donberg.ie/descript/t/tca700y.htm

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