Why do I keep blowing voltage stabilizers?

[79Series]

I have now put three voltage stabilizers in my '67 Series IIa. I've ensured that the units are attached to a nice clean area of bare metal for grounding and have attached power to the "B" terminal and the gauges to the "I". Each time I put a new unit in it works for a period of time and then suddenly doesn't and the fuel and temp gauge don't register.

Can anyone give me some advice on how to solve this problem?

[lumpydog]

Where are you obtaining the stabilizers from?

Use a voltmeter to check the power source going into "B" is supplying 12V.

Are you using the older/original style stabilizer that uses rapid on/off of the power to downsample it to 10V? Or are you using the newer electronic/solid state units that output 10V electronically? If you re not using the latter, I'd recommend trying them, as the original style units were prone to failure.

Try these from Moss Motors: https://mossmotors.com/solid-state-voltage-stabilizers

They're cheap - get a few spares.

Note - voltage stabilizers don't like constant power on/off/engine cranking. I've blown a few stabilizers during compression testing, where you cycle the starter off/off a lot.

[79Series]

All of the replacements have been electronic/solid state units from Moss. I'll check the power source to see if it's 12V.

[lumpydog]

I've blown a few solid state units from repetitive power cycling. Moss warranty's those units, so make them send you replacements. I feel like it may be a case of finding a solid unit and forgetting about it.