I have a 97 mercury xr6 150 and the voltage has been running 13-14 volts at around 1000 rpms and the higher rpms the higher the voltage gets it will reach almost 17 volts and tach will go loopy every now and then, does this sound like the voltage regulators?

Sounds more like bad battery connections or battery going bad. There is however the possibility of one of the regulators going out. Simply unplug one and run off the other.

How can I determine if it is the battery and when you say unplug one by that unplug all of the wires completely where only one regulator would be working

Swapped out batteries and didn't change anything so I swapped tach leads from one regulator to the other and the tach quit working, so would that be the bad regulator

My book says to replace as a pair. Was the plastic caps/shielding burnt? I had the same problem and when I changed both rectifiers everything worked great.
You can see the bad spots in the one I took off.

replace both units if the tach wont work on one its bad,

I had to replace my regulators...you need to replace both, and you need to do it immediately! Could create alot of damage to the engine if you don't. I was told to not run my motor at all until I replaced my. Use genuine OMC parts,too.

(edit)
DUH!!! I meant OEM, just not thinking!

I checked all the wires and connections for burns they all looked good. Went ahead and order two new Sierra regulators.

These are the connectors that went out when mine when bad. Make sure you have replacements prior to starting the job. I was told if you dont use the right connections you will just burn them out again. Also I was told to connect the negative battery terminal with a nut and lockwasher and not a wingnut to prevent future problems.

Im hoping you meant to say OEM parts instead of OMC hahahaha. OMC parts will not fit or work on a Merc.

I have those regulators off a blown engine that was charging fine. 75.00 each. OEM regulators. 281-312-9856

That would have been nice two days ago, but I have already ordered new ones.