Originally Posted by Mogs
Originally Posted by chanceafrica
Ive swapped out my fuel sending unit and my gauge reads 3/4 tank when full and when its at E it probably has around a quarter tank left. ive checked the gauge before installation and it has an ohm rating of 10/75 full/empty. the guy i spoke with at spectra(manufacturer) insists that is the proper specs for a stock 77dodge b200 fuel gauge. my van is a "factory custom" but all the pictures of 77 dodges seem to have this same fuel gauge. what are some causes of my improper reading do you think? should i check the lead from the unit to the gauge and see if there is an improper resistance reading due to wire breakage/corrosion at connections? has anybody had this same issue? the sending unit i put in looks like it has calibration tabs on the float arm closest to the unit, to change where the arm stops at full and empty. the guy at spectra says the unit does not come with calibration capabilities and i should not mess with the tabs , as they will not change the resistance reading. thanks for any insight on this issue. also tank is a stock 22gallon i think. i replaced the sending unit ground and sanded the chasis where it connects, next i need to check at the gauge to see if im losing resistance along the run, but not sure how to check it unless its completely full or empty.



Same issue here. Dodge 77 b200 van.

I replaced an old sender with a sunk float for a new spectre part from rockauto for a 22 gal tank.

I tested both the old and new units outside of the tank: with the floats manipulated to full sweep, the dash guage read 3/4 with both units. I read that someone elses gauge also reads only 3/4 on a full tank, so I was willing to accept this as a quirk. (I'm in the UK so I just assumed it's a thing for them to never read over 3/4 -maybe they never did from factory?) So I assumed the new unit was calibrated the same as the old one.

I have to try hard to brim the tank, with the nozzle clicking off at the station. I can get the guage to read 3/4. But then with some driving it drops drastically! After 6 miles I'm at 1/2 and another 6 miles I'm at 1/4. I'm pretty sure when it hits E I've still got most of a tank left.

I have tested the guage by earthing the sending unit and witnessing the dash gauge peg to full.

Getting a 5v reading from the dash volt reg too.

Anyone throw any light on this or did chanceafrica find a solution or any information?

Thanks.


My 82 B150 has always done the same thing since I bought it a few years ago. It shows somewhere around 3/4 when its full and when it shows empty, it only takes about 15 gallons. It might be something wrong with the gauge but it is always consistent so I've just used it as is. I also changed the gas tank because it was a bit rusty and smashed in (looks like someone backed over a big curb) and reused the fuel sending unit. Everything looked fine and it did the same thing.