Possible alternator problem
 

Running at cruise (3000-3500 rpm) I have 13.5-14 volts on my gauge. Running wide open it drops down to 12.

I am going to see if it also does it on my second battery.

A couple weeks ago I blew a power steering belt at WFO and I lost power and my gauges went haywire for a second. The alternator belt goes around the water pump only. The power steering belt goes around the crank, water pump and steering pump. So, when the belt blew my alternator quit spinning.

I was thinking that a piece of the belt may have smacked the alternator and knocked something loose. Or maybe it stopped abruptly when the belt blew?

I just don't get why it seems to be working at lower rpms but not at high rpms.

It could be just a gauge problem. Connect a good digital voltmeter to your battery or alternator output terminal to verify the voltage fluctuation.

The belt may be slipping at higher RPM.

I love the avitar, it say's it all, but did you forget to switch it from the uncensored?

Nah, just waiting for someone to give me some static about it.

Tough to do at 5000 rpms. :D

That's what I was thinking but no squealing, smoking, stinking or belt dust.

I went out Sunday and mid-range cruise still 14 volts. At WFO it would drop to 12 for 1-2 seconds then pop back up to 14 and stay there. Did this all day. :confused:

Not really. Snake a pair of wires from your battery or alternator to a location where you can see the DVM while driving. An old extension cord with the ends cut off would do. Just be careful not to short them together while running. I have seen dash mounted meters give false readings before due to bad or corroded connections. You need to be sure you have an alternator issue and not a meter issue.

A bad belt will just grow at high rpm. Once it glazes, it won't really burn, just slide thru the pulley. I always like deep-groove pullies for this reason- they bite more belt surface.

If nothing else, it's an easy test. Just stick the spare one on I know you have sitting on board already ;)