Has anyone tried one of the cheap (under $100),electronic dash spedometers,our gauge may be going bad and looking for a backup.
Yes
Amazon.com: COOLOUS C80 Universal Hud Heads Up Display 4.5'' Large Screen... (https://www.amazon.com/gp/product/B07HCB6RZH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1).
Reads about three MPH faster than you're going by other GPS indications. I do like the fact that it's ultra easy to see if installed on windshield. I really like it other than being off a bit.
I use the eBay gps Speedo. 70-100$
Reads right on.
Except in a long tunnel.
There is an app called Speedometer that is free and accurate. Also any gps could be a backup