16 replies to this topic

[croc7]

Is there a way to test the solid state voltage stabilizer -C34770a-that’s mounted on the back of the speedometer?

Edited by croc7, 16 June 2023 - 03:38 AM.

[slidehammer]

What issues are you experiencing? as I have just had to change mine. The problem I was having was the gauges would over read or under read and then they started working properly at the start of the journey and then started to either under read or over read.

Changing the regulator sorted the issue

[Spider]

The Solid State ones are easy to test with an ordinary Multimeter.

 

If you can get directly to the Stabaliser, then it's best to measure there, however an easier place check, though possibly could introduce some red herrings is if your Temp Gauge is electric and uses the Stabaliser, you can disconnect the wire to the Temp Sender and measure the Voltage on the wire. You can also do the same with the Fuel Gauge.

[growlerbearnz]

A solid state (semiconductor-based) voltage stabiliser should output 10 volts at the I terminal. 

[Steam]

What hs been said is correct however a faulty regulator ic can suffer from output drift and heat may cause the output to change. So while it may test fine initially when in use it may have issues.

[croc7]

The Solid State ones are easy to test with an ordinary Multimeter.

If you can get directly to the Stabaliser, then it's best to measure there, however an easier place check, though possibly could introduce some red herrings is if your Temp Gauge is electric and uses the Stabaliser, you can disconnect the wire to the Temp Sender and measure the Voltage on the wire. You can also do the same with the Fuel Gauge.

What I should have asked, is there a way to bench test it? I have one in my parts stash with a tag attached the reads “possibly OK.” So much for my accurate records…..

[Steam]

There will be 3 terminals. One is B or battery, one is Earth and one is I or instrument.
12v +ve to the B or battery terminal, 12v -ve to the earth terminal. Multimeter set to 20v dc and red lead to I terminal, black lead to earth terminal. A good unit will show a steady 10 volts.

[Spider]

There will be 3 terminals. One is B or battery, one is Earth and one is I or instrument.
12v +ve to the B or battery terminal, 12v -ve to the earth terminal. Multimeter set to 20v dc and red lead to I terminal, black lead to earth terminal. A good unit will show a steady 10 volts.

 

Or more likely for yours, 2 terminals (in 2 pairs). The Frame is Earth, but otherwise, test as Steam has suggested

[croc7]

There will be 3 terminals. One is B or battery, one is Earth and one is I or instrument.
12v +ve to the B or battery terminal, 12v -ve to the earth terminal. Multimeter set to 20v dc and red lead to I terminal, black lead to earth terminal. A good unit will show a steady 10 volts.

Good clear instructions but this voltage stabilizer has only two dual terminals; one annotated with an I, the other a B.

[Steam]

There will be 3 terminals. One is B or battery, one is Earth and one is I or instrument.
12v +ve to the B or battery terminal, 12v -ve to the earth terminal. Multimeter set to 20v dc and red lead to I terminal, black lead to earth terminal. A good unit will show a steady 10 volts.

Good clear instructions but this voltage stabilizer has only two dual terminals; one annotated with an I, the other a B.

They are Battery, Instrument, and the case of the stabiliser is the earth. Same testing procedure.

[Boycie]

Don't waste your time with the old tin can ones!  They're fragile and go wrong regularly now.

 

I use these-

 

https://www.ebay.co....tm/282642726457

 

Only problem being, they don't look wonderful.  

 

[croc7]

There will be 3 terminals. One is B or battery, one is Earth and one is I or instrument.
12v +ve to the B or battery terminal, 12v -ve to the earth terminal. Multimeter set to 20v dc and red lead to I terminal, black lead to earth terminal. A good unit will show a steady 10 volts.

Good clear instructions but this voltage stabilizer has only two dual terminals; one annotated with an I, the other a B.

They are Battery, Instrument, and the case of the stabiliser is the earth. Same testing procedure


Thanks for the help, the test was successful, reading 4.65v. Anyone interested in a slightly used voltage stabilizer? I can let it go for half price as there is still about half of the 10 volts left in it…….

[DUF2]

I think I may have buggered the instrument voltage stabiliser!

I have had the dash out working on the speedo, I put everything back together but omitted one of the connections, took the dash out again refitted the missing connection, then checked all was working as it should.

All fine, but then I noticed the fuel gauge fall to zero. Switched off, then restarted the car, fuel gauge goes to half way (half tank of fuel), but then the gauge returns to zero.

Duffy, is a ‘65 Elf which would have originally been positive earth with a dynamo. Some time in the past a 1275 A+ engine has been fitted with an alternator and is now negative earth.

The electric water temp gauge has been replaced with a capillary one so the voltage stabiliser only feeds the fuel gauge.

I suspect I may have “blown” the stabiliser, is there any way I can test this?

should I change to a more modern stabiliser?

[mad4classics]

There is an interesting article on how to test the Smiths bi-metalic stabilizer :-
https://www.wheels-a...age-stabiliser/

If you've got a solid state one they're easier. My solid state one recently gave really wierd gauge readings - turned out to be a bad connection (loose) where the I terminal was riveted to the PCB. Took it apart and put some decent copper rivets in both the B and I terminals - fine now.

Edited by mad4classics, 05 September 2023 - 05:40 PM.

[Gaz66]

Do the latest generation of gauges such as the Durite ones need to be stabilized?