I purchased one of the NEW electronic voltage limiters, for my 72 A-body and my question is...my service manuel says it should be suppling 5v to gauges but the new limiter shows 10v to gauges...I see that it has a screw on the back side,is this adjustable? Any suggestions or help?Thanks....

Before adjusting, check with the manufacturer. Tell them the voltage, whether you measured it with a load or without. Just cranking on an adjustment may let the magic smoke out. (Ask a local ham operator what that means!) 10 volts is too high. It may be high if it is unloaded. Older switching supplies go over voltage if there is nothing drawing current but I have not seen that in years.
Craig

If it is a stock mechanical limiter it needs a load to heat up the bimetal contact arm to have it start switching. If it is a Linear voltage regulator it should alaways have a solid 5-volts.
I have not used an electronic switching regulator (RTE?), but I think when power is first applied it puts out a higher voltage for about a second by design so the gauges respond quicker, then it backs down to the regulator set point around 5-volts.

A long time ago I read an article on building your own 5volt, electronic regulator - way easy and no gauge swings if the bimetal points stick . . . do a google search and you should find it. For the unit you have, contact the manufacturer and see what they say - I would think that it is adjustable and you need to just play with it . . .

Cheers

Mark

Search on here, I posted how to do the 5-volt linear regulator with a lower junction tempature version regulator and heat sink which should be used if driving the oil, temp, and fuel gauges.
If your driving only two gauges it may be OK with the standard 7805 regulator, but with three gauges the regulator can get into thermal shutdown. When that happens the gauges will still show a reading, but it will be lower than the true value because the regulator is turning itself off and back on because it is overheating.
Also, if the regulator looses it's ground, it will dump full power to the gauges. This is why the RTE regulator is a good upgrade, it does not have the issues the linear regulator has.