I tested my alternator and it is putting out 17-18 volts up and down cyclically at 2000 rpm.

I was wondering if anyone knows a way to bypass the voltage regulator on an 6th gen so I can be positive that the regulator is the problem before I buy a new alternator?

 

Take the alternator off and bring it to a parts store for testing. It is very unlikely the problem is anything other than the regulator itself though.

If you can find the regulator sold separate, it's easy to take the back cover of the alternator off and just replace the regulator. The regulator is a plastic part inside that incorporates the socket for the 4 wire plug.

 

Also check whether 7.5A fuse 15 under the dash is blown.

 

yeah, fuse 15 is good. But a while ago I checked under the intake mount and there were rust marks on the mount and on the wires, although none of them were open so I assumed that no splicing was necessary.

I just wrapped the wires and the mount in electric tape. I assumed this would be good enough since the wires were not frayed.

I found regulators on ebay, but they are selling for 40 dollars. does it sound like it is definitely the regulator, or could it be caused by a problem in the alternator?

 

Check the rotor for ground faults, that could full-field it and send the output out of control. Probably that's real rare compared to a bad regulator.