OK, if it's marked as per that then it's marked. You can easily "make" a 5-6V battery that will blow away a 9V. Something like this: Get a scrap length of PVC pipe or any other tube of appropriate size. Buy 4 D cell batteries. Get a long sheet metal screw, or maybe even a sheet rock screw, and drill a "cross hole" through the pipe. Stack your batteries in there. Three new (carbon zinc) batteries are around 4.5V, 4 are nominally 6V, Alkaline a bit higher "out of the box" So really 4 is what you want

Drop them in your tube and devise a way to contact the remaining end. A scrap spring and a second cross bolt would work.

(I've got bench variable voltage power supplies, so "I'm easy" in that regard.)

The 9V thing only came up because it was a "quick and dirty" way to quickly get something to move on the gauges. I don't believe anyone ever thought they could be used for accuracy.

Okay I think my set up was a bit screwy. I contacted rte, who made the limiter, and they said if the led light in the ivr is flashing then its for sure working. I remember it was flashing at one point in time so I'm going to hook it up and try it again. If it flashes then I can narrow it down to the wiring, or the gauges themselves. If I can't get it to flash, then Im going to make the homemade battery to test the gauges.

I'm not sure if this matters but do all of the gauges have to tested with a resistor on each at the same time. I've been doing just one at a time.

Okay so I sent it in to Bob's Speedometer and they fixed it and calibrated the gauges. Now i just want to make sure all of the bulbs work correctly. Is there a way that i can test to make sure all of the bulbs work?