I bought a used 55 6v dash to swap out my 6v idiot lights and install the gauges. I found that the "oil" and "battery" gauges are not a simple swap.

The "battery" gauge on the sacrifice dash had a yellow wire running through a metal "cage" to measure current. Any idea on how to use this in my 6v 55? The easy answer is to find a yellow wire - there are 2 at the headlight switch.

The oil gauge when wired up swing to "80 " when the ignition is turned on then back to "O" after thr truck is running. Do I need to change the sensor?

Anyone done this?

 

Howdy,

the ammeter is probably the easiest gage to "convert" to 12v. It doesn't care what the voltage is since it only measures current.

Also, If you reverse the connection to it, it will point the "right way" in a negative ground system . I never turned mine around since I removed the whole panel to replace it with a billet panel to use with modern gages. I'll be using a volt meter for the charge indicator when it goes back together


Regards,


Rick

 

So, you're replacing the gauges (which are a much better vitals check system) with idiot lights? Don't do it, keep the gauges. If you need good gauges, I'll send you some, that are still 6 volt and in perfect condition. If you are switching from lights, to gauges, take the oil light wire, and attach it to one of the terminals on the gauge, and run a jumper wire from one of the other gauges to the other post on the oil gauge. For the charge gauge, run the wire through it. For swapping to lights, take the wire to the oil gauge (not the one from the ignition switch, but the one from the sender) and put a bulb socket on it. Get a schematic for hooking up the light.

 

Ok for the oil. But what wire do I run through the charge gauge?

 

The 10ga yellow wire coming from the generator. It's supposed to go from the generator regulator, through the gauge, and then to the light switch. In an idiot light system, there are two wire attached to the headlight switch (a 14ga yellow that goes to the ignition switch, and the main 10 ga that goes to the starter solenoid). In a gauge system, there are three that go to the light switch (the two mentioned above, and the 10ga yellow that comes from the regulator, through the gague, and then terminates at the light switch). For your oil gague problem, sounds like either the wires are on wrong on the back of the gauge, or the sender unit is bad/wrong. You can take the wire from the charge light and run it through the gague, and terminate it at the headlight switch.

 

You have to remove the sender for the Oil idiot light (which was a simple on/off contact switch) and install a sender for a guage (which is variable resistance) and it has to be for that particular gauge.

The "Yellow Wire" runs from the "B" (battery/cutout relay) post on the voltage regulator, to your higher rated (of the two) circuit breaker (which on the other end distributes to your headlights on the middle left post of the headlight switch), it then goes through the induction loop of the Ammeter, and attaches to the battery lug of the starter solenoid. It makes no difference if it is positive or negative ground. The positive or negative battery post, as applicable, will be attached to the Battery lug on the starter solenoid as well. You are testing flow direction through the loop and it travels from generator to solenoid in both cases.

The wire goes in from the circuit breaker on the left part of the loop and out the right to the solenoid. However, I have seen some that operated backwards (because in some vehicles the gauge is upside down and sometimes gauges were made by POs using incorrect gauges with correct faces).

After you run the wire, turn on your headlights with the key off, and the gauge should show a discharge (in other words power is flowing from the battery (via the starter solenoid battery lug) to the lights, not from the generator to the battery lug). If you do this and it shows a charge instead of a discharge, disconnect the wire and run it in the other direction.

Also note that it is NOT unusual when at idle with high drw items powered, to have the needle show a discharge then jump up after your engine gets up to about 1200-1500 rpm.

J!

 

These the ones Mid-Fifty sells, ya think?

 

Well, that's a good question. And I don't have a good answer. I know the both LMC and Mid fifties sells new gauges with the sending units for the 53-55 models that are for use with 12 volt systems. I would imagine they sell the 6 volt sending units as well as the 12 volt sets. We just aren't sure if the gauges you have are 6 volt or 12 volt. One way to tell would be to test it by touching it to a 9 volt radio battery - but just for a second or two. If the needle deflects quickly and all the way, it's 6 volt. If it goes at regular speed and only partly delfects then it's 12 volt.

I would venture to say you have about a 95% chance they are 6 volt, and the sender mid fifties sells would be the right one.

Maybe the guy you got the guage cluster from still has the sending unit. ????

J!

 

Thank you for your clear thinking! I will call Mid-50 tomorrow. I bought the cluster on ebay. Pretty sure they're 6V.