I checked out the site on the LED voltmeter. Looks like a winner to me. Snap-On and etc. sell a probe [voltage]of that nature,but not set up right for our wants. There are ampmeters that will take the vibes ,Ford tractors use to have one,it never gave any problem. My '59' diesel has an idiot lite,sure, saved them a few bucks per tractor. An ampmeter would do the trick to. As for me I like to know what is going on with my wheels, that includes oil pressure ,and charge ,and on a long trip I wouldn't mind some temp readings as well.