12v. to 6v. instrument cluster
 

Hi
I am about to put a 12v. to 6v. reducer into my insrument cluster on my Cab 12 Chevy.
Someone said I need two of these one for the fuel guage and one for the
temp guage. Is this true? Also I've been told that I do not have to
reverse polarity. I am going to a 12v. negative ground setup.
Thanks Terry Clark

Are you sure.....?
 

Hi Terry

The temp gauge is mechanical with a bulb into the head and a fine copper tube to the gauge....... or...... are you using a GMC cluster which I beleive is electrical....

What about the amp guage....will it work on 12 Volts..?
amps are amps right ?????

Vested interest in the replies as I will be doing the same.

Bob C

My temp guage is electrical which suits up fine with the 261 cu. in.
sender. Amps are amps and that should not be affected. A fellow
on ebay selling 60 dollar 12 to 6 units said that the guage polarity
does not have to be reversed. Tommorrow I will know as I am getting the
reducer and will experiment... look for explosions in the west!!
Terry

Just to clarify for those still in doubt, an ammeter is not polarity sensitive, but will read the wrong way , if connected wrong.
If its showing a charge, when the lights are on, and the engine is not running, swap the wires around.

Lynn, I think you mean the ammeter IS polarity sensitive, but won't be harmed by reverse polarity. As you say the Charge/Discharge reading will simply be reversed, which is easily fixed by reversing the guage connections. I imagine this will have to be done if converting to negative earth system.

As far as I'm aware the other guages are NOT polarity sensitive because they don't need to detect current direction. In any case I imagine they'd be designed to survive reverse polarity, at least temporarily, in the interests of making them foolproof!

Interestingly Ford continued to use their 6V guages long after they introduced 12V systems, by fitting a 12V to 6V converter of some kind behind the dash. Eventually they got around to making 12V guages, which simply involves recalibrating the shunt resistor inside the guage.

Ok Tony, I submit! You are of course correct! :doh:
However, what I did achieve, was to prompt a more accurate response :D
At the end of the day, I am trying to help those who fear the vageries of electrickery.
Thankyou Tony for putting it so clearly. :salute:

saves me having to ask
 

Thanks guys,

I have been reading this thread with much interest, as I would no doubt be asking similar questions in coming months. I have examined a number of photos showing rear of instrument clusters (Ford), and tried to work out if they showed a common pattern of wiring. They dont, as far as I could tell, so this info will assist me greatly.

:cheers:

Now that is a good answer. I may well write it down to use in case I am ever wrong. :)

Rob, What you said, I took as a compliment...until I read the last four words. :fry:

Fair Dinkum
 

Lynn if your ever over the ditch, look Howard and myself up in Ganmain.

:salute: :salute: :salute:

Your message was perfectly correct Lynn, I was merely clarifying the context, which alters the meaning of the term "polarity sensitive". In other words I was being pedantic!

Tony W., your pedanticness (is that a word) Is the bit of info that the guy who didn't know, needed. He should now have a pretty good understanding of what he needs to know. That was my goal, and with your help, he has it pretty clear. (I hope) ( I tried several smart arse lines in here, but the wisdom that comes with age finally prevailed) I am happy as, with your post. :note:

Terry just adding a bit more to the discussion. There are many variations to the theme re the solution to suit your particular requirements. In our particular situation with the Chev. Aust. No.6. Artillery Tractor I decided to change to 12V.
A couple of things influenced the decision. First there was no wiring to speak of in the first place. Second we have a restored Canadian built (Otis) 40mm Bofors which is to be towed by said tractor. It is registered on the road and as such we need a boat board on the rear to travel from A to B. Everything except the starter motor and the fuel electrics were changed to 12VDC. The 6V generator was replaced by a refurbished 12v version. The starter motor is a 6VDC original but no problems running it on 12 which only left the electrics for the 2 fuel tanks with the single gauge and selector switch. A 12VDC to 6VDC converter was installed just for the fuel gauge electrics and the whole system including the necessaries for the towing aspect works very well. A couple of images of the wiring upgrade attached. Wire came from Vinwire in Melbourne. Rod