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Adjust voltmeter

Posted: Fri Feb 05, 2016 12:57 pm
by jamescarruthers
I saw a post on here within the last year about adjusting the voltmeter in the car. Mine has been reading 8-9V for a while and is obviously lying. I thought I'd try a tweak before replacing.

Can anyone else remember it? I have browsed and searched but with no luck.

Re: Adjust voltmeter

Posted: Sat Feb 06, 2016 9:15 pm
by brinkie
You can adjust the voltmeter with the potentiometer on top of the meter and by moving the needle itself. You need to open up the unit in order to reach it.
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But the accuracy is horrible at best, it's nothing more than a vague indication of battery voltage. I've tried to calibrate the meter and this was the best result I got:
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Re: Adjust voltmeter

Posted: Sat Feb 06, 2016 9:30 pm
by jamescarruthers
Excellent, thank you. I will have a go soon at this. Hope it's not broken as I can understand why it would just drop down so low!

Re: Adjust voltmeter

Posted: Sat Feb 06, 2016 10:14 pm
by brinkie
I would try and measure the battery voltage first with a digital multimeter, just in case the voltage gauge was right after all... :twisted:

If you want to calibrate the lower end of the range without a variable power supply, use a 9V battery.

Re: Adjust voltmeter

Posted: Sat Feb 06, 2016 10:38 pm
by jamescarruthers
What is "19", between the key and pin 5. A resistor?

Re: Adjust voltmeter

Posted: Sat Feb 06, 2016 11:07 pm
by brinkie
A fuse. The actual fuse depends on model year, there are three different fusebox layouts if I recall correctly.