volt gauge reading low
 

My 1987 series 3 dash volt gauge reads just a hair under 13v when running. I put my multimeter on the battery itself whist running and it reads 14.3v I assume its dirty connections but where do I start?
Thanks
Daniel

What does your handheld voltmeter read at the green wire at the back of the dashboard voltmeter? If the reading here is 14.3 but the gauge on shows 13, there's an adjusting screw on the back of the gauge to correct the reading.

If not....

What are you reading on both sides of the #4 fuse in the main (left) fuse panel? This fuse feeds the gauges. Is the fuse clean?

Start at the battery cables themselves, then the two "+" junction/distribution posts on the firewall, and check/clean/tighten the main ground under the car where the trans and engine come together.

If nothing improves we can dig deeper.

Cheers
DD

Mine usually reads just a tad under 13. As, I've checked real voltage with my patch cord to my VOM and found it just fine, I don't concern myself with a minor variation on the fascia instrument.