Our 50 Ford was converted many years ago, has a 12V generator in place of the 6V. However, other then the outside lighting, nothing else has been done to it.

Amps: reads fine, not dependent on voltage
Fuel Guage: I've determined it works kinda, when it's full it's "F" and when it gets near empty it drops to "E", there is no in-between.
Temp: Reads fine
Oil Pressure: running it reads 30, but there is also an aftermarket gauge.

Of course the dash lights do not work, the heater blower works, though...

 

Are you looking for input?

 

Ha, sorry I guess I didn't ask a question did I?

Oil Pressure, what should it be?
Fuel Gauge, any ideas why it acts the way it does?
Dash lights, are there 12V bulbs available?

 

I haven't done the conversion - you need to electrically convert the original guage inputs back to 6V. Check with Dennis Carpenter for the parts. Smarter guys will also chime in.

 

Have you looked under the dash to see if the gauges were properly converted, with an instrument regulator or Runtz regulators, etc.?

Mine is properly converted, and the oil pressure gauge reads 30 when it is actually (as measured with a good mechanical gauge) 50 psi. They can be adjusted to a point.

Many instances of the gauges working fine on 12v, but usually not for long.

 

My mechanical gauge reads 50-60 on oil pressure.

I'll have to look and see if there are any step-downs, but I don't think so, which I think is why the fuel gauge doesn't quite work right. Not to mention no dash lights...

 

Which gauges on the cluster need the step-down resistor?

 

Oil pressure, fuel, and temperature

 

What about the dash lights? I have none, what bulb should it take and what should I use?

 

If the original bulbs are in the dash, take them out (label them. Some may be longer than others) and take them to the auto parts store. They should be able to match them with their 12v counterparts.

 

Where do you hook up the step-down resistors for the gauges?
Where do you buy them?

 

I looked tonight, there are none I can see installed.

I did find 2 unknown switches, one I knew about. Not sure what they do. One goes into the factory harness with factory looking wires and the other goes to the flasher, on two poles... doesn't make sense....

 

MidFifty sells the voltage reducers that have instructions on how to hook them up. Go to this link, click on the small picture of the instructions where it says "Click image to enlarge". The instructions shown are for a 47/48 gauge cluster, but the process is the same for your truck.
1948-55 Ford F-100 Voltage Reducer, Elctrnc Single Gauge, Runtz

 

When installing your runtz, pay attention to their position relative to everything else under the dash. In particular, it's possible for the runtz on the oil pressure gauge to short against the vacuum motor. If your motor happens to have a film of oil on it from a sloppy attempt at oiling it, it's possible to create a pants soiling amount of smoke.

I'll let you guess how I know this.