Strange switch on dash

[wings04]

Hi guys, again new to the world of the 6.5, this is probably a long shot but here it goes,

I picked p a 93 2500hd reg cab long box, there is a switch mounted on the dash, when I turn the switch on it seems that there is load put on the motor?
when the truck is not running I can hear a "click" of sorts, almost like something is being engaged under the hood..?

Does anyone have any ideas what this might be??

[a5150nut]

Manual AC switch?

Auxiliary compressor/

Auxiliary welder?

[DmaxMaverick]

Glow plugs? Lighting? RV power?

[wings04]

I have ruled out ac, a compressor, there is no wiring for a trailer, no lights,

Maybe glow plugs? would the glow plug light on the dash come on when I flip the switch? it seems to do something even with the key out of the ignition..
whatever it is it certainly draws power, and puts load on the engine..

[DmaxMaverick]

If it's glow plugs, it may or may not light the WTS lamp, depending on how it's wired. You can check the voltage before/after the switch is thrown, at a GP (don't leave the power on too long, 10 seconds or less). The clicking, regardless of what's being powered, is probably a relay. Are you able to trace the wires?

Also, if this is/was a plow truck, it could be for plow power and/or a beacon. However, if it's pulling a load on the engine, something of significant current draw is still in operation.

[wings04]

I actually just tried it again, it draws enough power if in the on position prior to start that the batterys slightly struggle to start the truck...?

I am going to try trace these wires.

[jeffscarstrucks]

If it has what looks like an extra AC compressor it is an air compressor,usually a Ford type. A buddy of mine has these on his farm trucks. Just a thought, JEFF

[trbankii]

In my house there's this light switch that doesn't do anything. Every so often I would flick it on and off just to check. Yesterday, I got a call from a
woman in Madagascar. She said, "Cut it out." -- Steven Wright

Quite a few possibilities. Hard to say without tracing the wires.

[wings04]

Ok guys.. tell me if this makes any sense, I traced the wires and well, there is a hot wire going to the ac power terminal,, however does not seem to have any affect on the a/c... what the hell....

[rustyk]

Well, that pretty much narrows it down to the proton torpedo launcher :D.

Seriously, you'll need to do more research, because if it drags battery voltage down enough to make starting harder, either it's energizing a BIG legitimate current draw or a short.

[winemaker]

Perhaps the proton torpedo launcher, but I'll bet it's the flux capacitor. If you measure the current draw, I'll bet it's 1.21 gigawatts. It's a Delorean, right?