can u wire a fuel gage backwards? Or will it burn up I wired the gage the way i thought it was before the only differance is i converted to 12 v installed the volt reducer but when i filled the tank it bairly read a 1/8 0f a tank so i took out the sending unit and moved it up and down the higher the float got the lower the gage level got so u see the reason for my asking any help would be greatly apperated Thanks
Funny thing is, i pretty much experienced the same thing last week, when i installed a new gas gauge and couldn?t believe my eyes, once hooked up. Sorry i?m not of any help, but curious, if anybody has a solution for that problem...
Wiring diagram ! To avoid any short damage in your system i advice you to use a wiring diagram. Using a voltage reducer is not really neaded if the install is done in the right way and everything is converted to the new 12 volt system. Did you installed new wires for the 12 v. el system or are you still using the 6 v. original wires as there is a difference there in size/dia ? Martinius.
Fuel gage problem Same 6 volt fuel gage / New complete wiring system / Followed the print / Good ground / New sensor / seems to be working good the only thing not sure is the connection on the gage / Could not tell which was which post / So took best guess by some pictures on line . Thanks again for any help.
Nate has answered the question about the wire position on a fuel gauge many times so do a search like "fuel/gas gauge wiring" and it should come up. Yes, you can hurt a fuel gauge by wiring backwards. Originally there was a narrow cardboard strip under the two terminal post nuts that had "Sender and Ignition" imprinted in it but they are usually long gone. Once you know it's wired right ground the sender wire and the gauge should go to full. If not the gauge is bad. Also try running a jumper from a good ground to the gauge cluster housing; never seen this bad before but eliminate all possibilities. I hope you used an electronic voltage reducer, like a Runtz, and not one of the ceramic ones. The electronic gives a constant 6 volts while the others vary with the generator/alternator output. There are knock-offs of the Runtz on ebay now for a fraction of the price.
Fuel Gauge The left most post is the power feed . The right most post is the sender connection . it's critical to use star washers under the gauge to dash nuts as that's the ground path . What Evan said about a proper voltage reducer as the resistor things don't properly cut the voltage . I always add a ground wire from one of the sender to tank screws , down to the frame and another one from the frame to the cab . You cannot have too many grounds . When the gauge is properly connected , power it and disconnect the sender , this should drive the gauge to full , touching the sender wire to the tank should then drive the gauge to full empty . If it passes this basic test , then anything else will be the senders fault ~ Stewart Warner makes a universal sender that fits & works better than the Chinese repops , i got an N.O.S. AC sender off E-Bay for my '49 the thieving a$$hole who bought it , prolly tossed it in the trash . BTW : the wiring diameter makes NO DIFFERENCE ~ 6 volt wiring is far heavier than is 12 wiring and gauges don't draw even 1/4 ampere so it's moot as long as in good shape , no splices / patches .
Guess what I'm trying to get ironed out? So with everything else working, I thought~ eh, why not try to get the gas gauge to work as well? Bill Hanlon gave me some advice, and so here I am looking at this thread again. Question... Nate, are you talking about the posts as looking at them from under the dash, or from sitting on the seat, looking at the gauge? Thanks!
BTW, NAPA has a 12 to 6 reducer(for gauges). I see Runtz are specifically mentioned. Is there a reason why I should not get a reducer other than Runtz if it is made for dropping 12 to 6 for gauges? Just wondering because I could get this first thing tomorrow and get it installed (hopefully to the correct post) tomorrow morn. Thanks for your advice/opinions.
Runtz is a 3 terminal solid state voltage regulator. It will provide 6 volts no matter what the load applied to it is, up to the point when you demand too much and the smoke gets out. SOME of the alternatives are just resistors, which will only supply 6 volts at one particular current load. That is what the NAPA solution (echlin part #vt6187) is. It is designed to drop 12 volts to 6 volts by inserting 1.5 ohms into the circuit. In your case, the resistance in the gas gauge is a LOT more than 1.5 ohms, so the actual voltage supplied to the gauge would be MUCH more than 6 volts. You could connect two of the Echlin parts together in series and use the center point to tap off 6 volts. It would look like this: Switched 12V -------- "Bat --- Output" ------tap 6 volts here ------"Bat --- Output" ---- Ground This would work, but will pull a constant 4 amps from your charging system any time the key is on. And the Echlin devices would get at least warm to the touch. Stay away from any solution that is advertised to provide 6 volts for multiple devices at the same time. It is possible to do so, but would be large and cost lots of $$$.
AARRRRrrrrrrrggggH! Well I want to do it the best I can if I''m going to do it, so I guess I'll order and wait for a Runtz to come in~ *sigh* and SOB. In the mean time, I look forward to finding the answer to the other question about which post is the power feed post. Thanks, Bill!
The sender will go to the F post Power to the E post If your 12 volts and using a 6 volt gauge then use the reducer on the power side. Originally there was a red waring tag attached to the sender post of the gauge If you refurbished your housing and painted the inside white, make sure you clean the paint off where the gauge touches the inside. That is a ground path
Fuel Gauge Wiring Left most post : sitting in the driver's seat . The resistor typ reducers often will smoke your original gauge , I'd never use one for the fuel gauge . Radio Shack sells a three terminal voltage reducer for about $5 that works dandy but I don't remember the part # ~ . if you go in looking , DO NOT tell the sales boob it's for a car ! he'll *instantly* says ' oh , we have nothing for that ' . All he needs to know is : you want to drop 12 volts DC to 6 volts DC . The Radio Shack reducer cannot be used for heater blowers etc. ~ it's far too delicate .
Thanks again, Tubby! GREAT photos clear everything up! I just need to be patient and wait for my Runtz to come in. (Well, first I have to get it ordered...)
So ? . GOOGLE it mon ! . There's still R.S. stores all over the place . I go into Boyle Heights (East Los Angeles) for one .
Zig: Another picture of the back side of the instrument cluster. The sending unit wire goes to the red tag.
Ummm~ Interesting picture there, Bill. HA!!! (What I see is a red circle with a line through it.) Tubby's picture has a red tag that says "This side to sending unit". Is that what you are speaking of?
Okay Nate! (First of all, I hope you're having a wonderful time with your son!) So I "Googled it, mon!" Here's what I came up with. http://www.voltage-regulator.org/tag/12v-dc-power-supply-radio-shack Of course, when I called I asked if they had any 12V to 6V "reducers". "Nope." So, if anything they have shown here is what you are talking about, I will call them back and see if they have it in stock. In the meantime, for the first time, I am starting to feel much frustration at being so close, yet so far away...
There is that option! It really sounds more inviting then getting under the dash and trying to see stuff I can't due to BIFOCALS!! The only deal is, I know my wife will be driving this, and a working fuel gauge would just be a better option...
