Got a chance today...

to go over the wiring behind the dash. I replaced all the short wires & put in a new fuze & recepticle. I proceded to attach the red lead of the meter to the disconnected + batt wire & started my probe. Full juice on the ammeter posts, cool. No juice on any of the posts on the ign or the light switch. I turned the key every which way. Nothing. How do I go about testing the light switch & the ign? What other things can I do to chase this gremlin through the wires? Thanks - Mike

I have a wiring diagram for a 450, would that help. I think it is the same as a 400, and I have one that is modified to show wiring with an alternator. As far as the switch goes, set you meter for ohms, or resistance. Hold both leads together, it should read 0, or real close. Some meter have an audible conductivity setting, this will work also. Do you have a switch and push button, or just a switch? For a switch and button, Connect your meter across the two terminals of the key switch and watch your reading. When the key is off you should get an infinant reading, turn on it should read 0. Same with the button switch. When the button is off you should get an infinint reading, push it and it should read 0. I do not know terms if it is just switch, but can check in morning. There should be a power feed term, an "on" term, a "start" term, and I think an "accesery" term. Turn switch to right, this should be "on". Using your meter on ohms, hold black lead on on terminal, check all others with red lead, results, yes no, if yes, hold switch to the start position(spring loaded)and check with read lead, results yes no, if yess you are done. make drawing of switch to mark terms. if no, move red lead to previous term, and still holding key to start, use black lead to check. Power to the switch should come from ammeter, your light power would of come from voltage regulator. Let me know, a wiring diagram is the only way to do it, along with some checking with meter or test light. hope this gets you in the right direction to start.

If there is no juice on the light switch, or the Key Bat terminal, the load side terminal on the amp meter is corroded, Touch the leads at the terminal on the amp meter to see if they have juice, It may be the real problem. JimN

is the green wire the batt wire on the ign switch? There's supposed to be power to the batt post? If that's the case, where's the other end go? The load post on the amp meter? I was wondering where the key got its juice. I get a good solid "0" reading on the amp meter posts, btw. - Mike

Yes the amp meter must have Battery volts at both terminals all the time. The switch should get power from the amp gauge. Either terminal on the amp gauge should show battery volts when the other (black) volt meter lead is grounded. If there is none, the wire from the non load side of the amp meter should run directly to the starter, and connect to the relay at the big terminal connected to the battery plus cable. The wire is 10 gauge. Jim