has anyone swapped an instrument cluster from the warning lights to gauges? it appears the wiring harness is different ?

 

I suspect that the main difference is the wiring for the ammeter. The wiring for the oil pressure light should be nearly the same as the wiring for the oil pressure warning gauge.

 

Oil/Amp GAUGES vs. Oil/Amp WARNING (idiot) LAMPS:

The wiring harness, printed circuit board and the instrument cluster back are different.

What year truck are you working on?

 

Warning light cluster plug is about 2", gauge cluster plug is 2 1/2". Location of the wires in the plugs is different; #10 is dash lights on gauge cluster, #2 on warning cluster, as an example. All the others appear to be different as well. Oil wire is same color, white with red marker, gauge plug #17, warning #10.

 

I've swapped them before, but its not a quick parts change...
What I've done before that has worked well was to cut the plug off the harness of the donor truck the gauge cluster comes from. Then I use it to replace the smaller plug on the receiving truck. I'd recommend following a wiring schematic to make sure all the wires are correct when matching and soldering them from one plug to the next. Keep in mind, with this method the ammeter will NOT work correctly and may have the potential to create a fire since the ammeter requires very precise length, size and connected wires (the ammeter shunt is what it it called I believe) and the truck with lights does not have this.
I actually send the original ammeters to: Rocketman's Classic Cougar Innovations to have them converted to a volt meter (more expensive than an add-on but keeps a stock look). This has worked out pretty well for me and if you happen to upgrade your alternator the voltmeter is a bit more forgiving.
The sending unit on the engine for the dash oil gauge is different than the switch on the engine for the oil light in the old dash as well.
The whole swap is only mildly expensive and a little time consuming but it looks nice! I guess it does save you from replacing the entire truck wiring harness though...
Hope this might save some time.

 

sounds fantastic.Lights it is. If I need a gauge then an aftermarket set will be, well, I know where they sell those. This is a work truck. welder and torches and compressor on the back, no need to make it fancy. Year is a 1978 snow fighter.