gen lights and battery

[bryab123]

went out to start my truck this morning and it cranked over 2 times and then started dragging, took the batteries and had them tested they were marginal so i replaced both batteries and it fired right up. i have been driving it all day and this evening i noticed the gen 2 light flashing at highway speedsthen goes off when you slow down, belts are tight, batteries are new, volt gauge is where it should be. what should i check first? also where can you buy those brown military batteries and what do they cost?

 

[Westech]

The 6TL batteries cost around 160 bucks new. There are deals out there and I'm sure someone will pop in and say where. My alt is having problems at low RPM's. That is when mine flashes. Volts seam to be fine and always starts. I would say the volt regulator is starting to frits out, that's my guess.

 

[bryab123]

are left and right alternators the same, can they be interchanged?

 

[uscgmatt]

If they are both stock they are the same thus interchangeable. They are 12 volt 100 amp isolated ground alternators. Hope this helps.

Matt