Another 12v conversion question...
Thread Starter
|
Junior User
Joined: Jun 2013
Posts: 80
Likes: 0
From: Inverness, Fl
Another 12v conversion question...
OK...I searched the forums and found a great deal of information on converting to 12v. What I didn't find is the one piece of information that I really needed. I have everything figured out when rewiring my truck. Everything went without a problem. However, the only thing I still have on my to do list is the fuel gauge. This is one of those areas that I don't know much about. I want to run new wires and hook up the sending unit to my new 12v Autometer fuel gauge. Does anyone know how to properly wire this? I know that the 6v system had a positive ground, and the 12v is negative. I don't want to hook it up wrong, and arc a wire anywhere near my gas tank. I have the stock style behind the seat tank, and the original 6v sending unit. Can this be done? Do I need a new sending unit? Do the wires hook up in the same spot? Any information is helpful. Thanks guys!
Hotshot
Joined: Oct 2004
Posts: 15,882
Likes: 88
From: Durham NC
You will need a sender that matches the resistance range of the gauge to read properly. Read the guage instructions if new or contact the manufacturer to find the range needed and possible recommendation for sender choice(s). Since the gauge is reading the sender's resistance there is very little current flowing thru the wire between the tank and the gauge.
Logistics Pro
Joined: Nov 2011
Posts: 4,685
Likes: 81
From: Northville, MI
OK...I searched the forums and found a great deal of information on converting to 12v. What I didn't find is the one piece of information that I really needed. I have everything figured out when rewiring my truck. Everything went without a problem. However, the only thing I still have on my to do list is the fuel gauge. This is one of those areas that I don't know much about. I want to run new wires and hook up the sending unit to my new 12v Autometer fuel gauge. Does anyone know how to properly wire this? I know that the 6v system had a positive ground, and the 12v is negative. I don't want to hook it up wrong, and arc a wire anywhere near my gas tank. I have the stock style behind the seat tank, and the original 6v sending unit. Can this be done? Do I need a new sending unit? Do the wires hook up in the same spot? Any information is helpful. Thanks guys!
I would remove your original sending unit from the tank if you have not done so already and with it hooked up and grounded see if it moves the needle on your old dash gauge. Does it provide full range, empty to full, when you move the float within the measured limits of the gas tank? If so it is then a simple matter of measuring with a multimeter the ohms resistance within that range of travel. Then compare that to what your Autometer gauge needs.
Here is a link to a similar question on the Autometer site that might help you:
http://www.autometer.com/tech_faq_answer.aspx?sid=1&qid=56
Hope this helps,
Logistics Pro
Joined: Nov 2011
Posts: 4,685
Likes: 81
From: Northville, MI
I didn't know that Ross. (This forum is great! There is always something to learn regardless of your experience level. 
) Every older car or truck that I have worked on has been negative ground. The fact that they can be so easily converted may be the reason why. See the following:
http://www.hotrodders.com/forum/why-neg-ground-vs-pos-ground-181903.html#post1296040
) Every older car or truck that I have worked on has been negative ground. The fact that they can be so easily converted may be the reason why. See the following:http://www.hotrodders.com/forum/why-neg-ground-vs-pos-ground-181903.html#post1296040
"These could be easly converted to negative ground by swapping the connections on the igntion coil and re-polarizing the generator. The starter motor always seemed to rotate the correct direction regardless of polarity. And for a short period of time 6 volt negative ground systems were used, such as on my 1954 Chev truck....or was in a 1952.....can't remember now."
See this comment on corrosion on positive ground systems:"I did find this on Wikipedia: In modern automobiles, the grounding is provided by connecting the body of the car to the negative electrode of the battery, a system called 'negative ground'. In the past some cars had 'positive ground'. Such vehicles were found to suffer worse body corrosion and, sometimes, blocked radiators due to deposition of metal sludge."
Thread
Thread Starter
Forum
Replies
Last Post
columbia1spring
1973 - 1979 F-100 & Larger F-Series Trucks
24
Aug 22, 2017 12:44 AM
joey2fords
Electrical Systems/Wiring
3
Dec 3, 2015 06:29 PM
