Ok, so my problem is this. I need to install the Hydroelectric Magnetosphere Regulator (I typed this without any help!) in Gecko's lovely power plant. The catch is I can't get past the first Yellow security door. I thought "it's yellow, just like the card I picked up in Klamath. Message: "This does nothing". Ok, I go see Jeremy, the supply guy. He's a handful. Like a little geek from a high school's biology lab, he needs a "Request Authorization Form" and says I can get one from Harold or Festus (to whom I have been trying to go). Now, Harold doesn't have the dialogue available to get the Form. I am stumped. So I modify the game a little and get me the only item named "Yellow Reactor Keycard" Again, nothing. I used the "use on" command... Can anyone help ne, cause I want to do this the "good guy way", but right now i am half-a-mind to kill every rotting zombie in there and make Lynette happy.
So help, please.

The one you picked up in Klamath has nothing to do with the reactor. Whether it should be or not I'm not sure, though the Enclave is somewhat tied to the reactor, if only for flavour purposes. That key may have been originally designed to be used at the plant, but was possibly left out of the final cut. You can find a yellow key card in Gecko, possibly in the plant itself, have a look around. Also try to open the door, unlocking doesn't combine an open command, you need to unlock, then open.

As for the forms, you need to be authorised them, of course, you have no reason to obtain authorisation, so you need to steal them. Have a look around in that building Harold is in.

I got the form and the keycard in the same desk (next to Harold). And I know how unlocking works. I did the "use on" on the door. Again "This does nothing"...

There's also a card in one of the lockers in the reactor. I wasn't trying to sound condescending, thought I'd make sure just incase. Make sure you're not confusing the other key you picked up with the one you already had, any key you find in gecko should work in the reactor, however if for some reason the key in Harold's desk in bugged, try the other key found in one of the reactor lockers, there's one north-east from the front desk (isometric north-east, to avoid confusion).

Thanks...I don't mean to be ungrateful, but do you know how to find the red one now?

Don't worry about it. It's what I'm here for The red key card should be in the first room on your left after you come through the yellow doors into the next section of the reactor. Not very imaginative I know, but that's where it is.

Thanks, again. Now i am going to blast critters an' folks (in a bad southern accent) all the way!