three times now in the last 4-5 months, when i go to start my d-max, ZZZZZZZZZZZZZZZZZZZZZZZ.

i turn off the key, and return, and it starts up

is the starter starting to go bad? should i replace it now?

Mine did the same thing, sometimes I would have to try two or three times, it need a starter and a flex plate.

First check the batteries-- you have to separate them to test-- then make sure that cables are clean and then check all the connections. I am betting battery-:mad:- but if one is bad, you should replace both with the same type and CCA. One bad cell will drain the other battery down to the same level.! :)

Also, get under there and check the starter bolts! My buddies poor Dodge had the starter hanging. Once he went to start it, zzzing!! Bought a new starter, went to put it in and realized bolts were loose!

does anyone have a diagram as to where the starter is on my o3 d-max?

If you can find the oil filter, the starter is on the opposite side. A good alternator shop can freshen up your starter for a lot less than a reman. Sometimes they can even R & I it for dirt cheap, saving you from climbing under there in the first place (helpful it's cold out out, or you're fat and lazy like me.) Sounds like it just needs a good clean and lube inside.