Voltage Gauge

[nickcollins]

My voltage gauge on the dash just suddenly stopped working, no reading at all. I checked at the battery and its charging fine so I'm guessing I need to check the ground or connections. Any ideas where to start? All the other gauges are working fine

Thank you

[Bitsyncmaster]

It would probably be a faulty gauge or bad connection on the gauge (flex circuit board). The volt gauge shares voltage with the temp gauge and the ground for the volt gauge is shared with the high beam light in the dash.

[Shep]

If memory serves (no car to test on), pulling high beam stalk towards driver shines high beams plus high beam indicator, that would be a good way to test if the ground works.

First question I do have real quick: key in ACC mode, engine OFF, does battery light come on? Just while we're checking binnacle electrics. Mine didn't, or kinda barely did in a weird way, alternator was faulty and died two months later. If it comes on, that's good. If it doesn't, check the bulb first, then if the bulb is fine, the alternator. Incandescent bulb in that spot, current must readily flow both directions by design from what I gather.

Did the temp gauge work as expected also? Operating temp, etc.? (Thanks Dave for current flow, I had no idea what it was myself!)

Worst case, I think you can remove the gauge itself and test it with a "wall wart" type power supply. Try various voltages, it doesn't take much amperage for those gauges to move, and even then, nearly every modern "wall wart" has overcurrent protection, i.e. they will simply not supply power if you try to draw too much. Great way to get DC current from your house. (Or perhaps more simply, direct connect to the battery itself? Wall warts just give you a more stable voltage reading really.)

[Bitsyncmaster]

Volt gauge can be checked with a voltage source up to 15 volts. I would not check the other gauges on the sensor side with a wall-wort. Most wall-worts don't have electronic current limiting or it may be to much current even if they do.

[Shep]

I would not check the other gauges on the sensor side with a wall-wort. Most wall-worts don't have electronic current limiting or it may be to much current even if they do.

Oops, wasn't clear enough on that one, you are correct. Voltmeter is like an analog multimeter, which doesn't need much current. Other gauges have better/easier ways to test. Thanks for pointing that out!

[nickcollins]

The high beam light on the dash works and so does the temp gauge so I assume it must be the gauge itself or its connection. Battery light also works.

[Shep]

As a "while you're in there", wingnuts to replace the binnacle nuts. Makes removing/replacing a million times easier. I can do it seated comfortably without reaching too badly. At least, until it comes time to unplug the speedo and electronics, but it saves extensions and tight reaches and small areas.

Keep us posted on the gauge. I'm not sure it's the connection given the low current draw and protected environment. If I were a betting man, simple case of the coil having a break inside somewhere would be where my money goes. Easier to swap than repair.