voltage limiter

[poppa]

Hey , I am upgrading to the electronic dash voltage limiter. I think the mechanical one uses a "capacitor/condenser" , should I still use this? Thanks

[BLK 68 R/T]

It is not needed with the new electronic limiter.

[poppa]

Thanks for the quick reply

[johnjjo]

Today I burned my temperature gauge because apparently instrumental cluster have to be grounded for a limiter to work correctly, otherwise the output will not be 5 volts and will run as feed input at 12v...... But even with that for some reason my two extra limiters that I have at the shop output not at 5 volts, it jumps between 0 and 5 non stop and sometime reaching 7v..... My question is does it supposed to output exactly 5 volts or its ok for a voltage to jump like that?
Thank you

[Pete in NH]

Today I burned my temperature gauge because apparently instrumental cluster have to be grounded for a limiter to work correctly, otherwise the output will not be 5 volts and will run as feed input at 12v...... But even with that for some reason my two extra limiters that I have at the shop output not at 5 volts, it jumps between 0 and 5 non stop and sometime reaching 7v..... My question is does it supposed to output exactly 5 volts or its ok for a voltage to jump like that?
Thank you

Hi,

The instrument voltage regulator is an old technology electromechanical/thermal device. A coiled heater wire heats a bi-metal strip with electrical contacts attached. The heater warms the bi-metal strip which bend until the contacts open and turn off the heater while opening the contacts from the 12 volt input to regulator output. without the ground to the regulator the heater never opened the contacts and the output remained at 12 volts burning out your temperature gauge. what most people don't consider about these old devices and the whole gauge system is that they are thermal and work on heat. The current flow and voltages in the system just provide the heating.

You can't measure the output of these regulators with a conventional voltmeter. All you will see on a digital type meter is changing numbers. With an analog voltmeter, one with a needle pointer, you will just see a swinging up and down pointer. So, your meter will not show a steady 5 volts. If you see a pulsing reading and not a steady 12 volts the regulator is likely working.