voltage stablizer

[richard1705]

tried a search but nothing coming up how may wires should be connected to the stabilizer on back of speedo there are 4 connectors but only 3 wires are connected is one missing
thanks
richard

[steve.n]

Richard the terminals are paired i.e. two terminals are common. two wires on one pair are 10v out to gauges, single connection is 12v supply in. earth is via its own body to the speedometer or tachometer.
IF this makes sense.
Steve

[richard1705]

ok so I will have 1 connector with nothing on it also my fuel gauge is still reading high

[steve.n]

Correct, four terminals, only two electrical connections. 12v in on one side (one spare terminal), 10v out on the other (two wires, one to the fuel gauge and one to the temperature gauge. You need to connect a multimeter between an earth and the output side of the regulator, should be around 10v with the engine running.

[StagJonno]

Correct, four terminals, only two electrical connections. 12v in on one side (one spare terminal), 10v out on the other (two wires, one to the fuel gauge and one to the temperature gauge. You need to connect a multimeter between an earth and the output side of the regulator, should be around 10v with the engine running.

My understanding of these V regulators is that they do not output a steady 10V, but rather switch the battery voltage on and off so that an average of 10V is achieved. Therefore, at 12V, the regulator would be on for 5 sec and off for 1 sec. At 14V, the off period would be extended to 2 sec. In reality, the times shown will be ratios, so eg it could be On 10 sec/ Off 2 sec and On 10 sec/ Off 4 sec respectively..Because the operating process is thermal (heating a bi-metallic strip for both the V Reg and the gauge), then it could be a few minutes before it reaches steady-state operation. This system provides good immunity to the range of battery voltages seen during normal running (12V - 14.5V).

Some owners have replaced the OE V Regulator with a single component electronic regulator - very cheap if you have reasonable soldering skills, and you do get a steady 10V out. Though OE V Regs are available from the usual suppliers for ~£15.

Jonno

[DJT]

This is worth reading: https://socforum.com/forum/filedata/...9&d=1532024205

[garyf]

http://www.britishv8.org/articles/mgb-voltage-stabilizer.htm

I got hold of a new one recently but I will be building a electronic one like this with the old case

[StagJonno]

Nice one, Gary.

[richard1705]

cheers guys temp sitting much better now will keep an eye on fuel I suppose
richard

[richard1705]

temp gauge now perfect but the fuel is undereading as I filled the tank and its showing just over half I have changed the fuel sender and stabilizer now whats left the gauge itself

[StagJonno]

It could be the gauge, though it could be poor connections in the circuit. You could try connecting the Temp gauge to the fuel gauge connections, as they both work the same way.

I don't know how well the needle in the gauge might withstand being pushed hard against the "Full" stop - there;s a possibility that it bent. Worth checking this out next. I've heard that there is a way of adjusting the operation of the gauge though this needs a variable dc voltage supply.

The attached official testing procedure may be of interest. TSB T-66-40 Testing bimetal fuel and temp gauges.pdf

Jonno

[richard1705]

with the sender still connected if I push the arm up the needle goes up put it back in the tank full tank goes back to middle again
I think the arm is still up as it goes in the tank

[StagJonno]

Seems the gauge is OK, then. I know on my car, it's not easy getting the tank properly full - seems a bit of a random feature. Also, are you sure your float hasn't taken on petrol through a pinhole?

Jonno

[StagnJag]

I replaced my voltage regulator 5+ years ago with a repro one. I had to dismantle it recently as one of the rivets was loose giving an intermittent connection. I was surprised to find modern components inside!