How accurate are 80s dash guages?

[markjs]

I've been wondering about my voltage guage ever since shortly after I got this car ('84 GL Wagon).  The alternator puts out a steady 14 (13.99 at lowest) and stays steady revved or not, so I am hoping the alternator is OK, and no battery dying issues (read 12.6 last) I looked, so I hope it is too.  Thing is, if the battery drains at all, that needle goes off or runs around 8v normally.  IT was over 12v most of the time when I first started driving the car and it got up there again and stayed for a while, now it's back to showing 8, normally.  Any idea?  I'm thinking it may be shitty grounding to the dash, or somewhere in the circuit, but the other guages vgve me no real troubles.

Edited April 4, 2018 by markjs

[andrsn]

I've had the opposite problem. My oil pressure and temp gauges are wild but my battery charge seems to be accurate. They go from zero to hero and back over and over. I bought a cheap set of Bosch aftermarket gauges. Once I get them wired in and working I'll take the stock gauge cluster apart and mount them in there so they look clean. With a recent ej swap, its piece of mind...

[skishop69]

Based on your numbers and my experience with those gauges, the volt gauge has gone bad. The one in one of my Brat's did the same thing. There are a few companies out there that can rebuild gauges but it generally isn't cheap.

[GeneralDisorder]

Could be a bad gauge but you won't know till you double check the gauge input on the back of the cluster. Could be a solder joint issue also. Japanese stuff always has problems with cracked solder joints. They are still fighting this issue - 05-08 Legacy's routinely have the map light assembly cause SRS codes due to cracked solder joints. 

 

GD