im trying to install a voltmeter in place of the factory amp guage in my 74 blazer. but having problem with getting the guage to show the correct voltage. i ran a new power and ground wire to the guage but it just barely moves the guage. there is 3 prongs on the back of the guage, and i got the guage as a factory replacement from LMC parts. from what ive read 76 and newer blazer have the voltmeter. so can someone send me a diagram showing my how it's wired? ive tried several different combinations of power and ground to the 3 posts and none seem to show the correct voltage. some make the guage show way too high and others make it go backwards. please help. Thanks

 

I don't know why you have 3 connections but I'm thinkin one may be for illumination.

Check this out, it saves me from typin it all out and you can save it to look at again

http://www.sunpro.com/publish/2007/0...ench_16429.pdf

(It's NOT in French, I don't know why it says that)

As far as the meter running backwards, that means it's hooked up incorrectly. Also remember that it won't show a lot of voltage until it's up past idle speed, so you probably had it hooked up right when you said it barely moved the gauge.

Hope that helped!