Fuel Level Sending unit HELP!
 

I have a few questions regarding it....

1.) Is there an a place one can use to check the wiring on it with out dropping the tank?

2.) where can I find a new one or can I use a universal replacement part?

3.) What are the odds of the low fuel light working while the gauge does not?

The car is an 85 Rx7 GS with a 12 a. I've pulled the gauge cluster, and checked the wires on the back of it (Not sure how it works but I assume its magnetic as there is no motor? The wires all look good however I do not know what plug controls the fuel gauge so I cant check it with the Voltage meter.

Any help would be great! I'm going to hunt down a book for it soon.

Remove the right rear tire. Remove the plastic panel covering the rear of the wheel well. The sending unit can be removed by taking out the small screws around the edge of the circular plate. They are easily stripped. First, test the plug and terminals per the FSM, Chapter 15. A few resistors from Radio Shack can be used to replace the special Mazda tester.

You do not have to drop the tank. The unit is right behind the lr wheel (remove the fender liner). Usually the contacts are rotted right off or dissolve when you touch them.

Didnt even have to lift the car, it appears the P.O. did some work on the unit and replaced the clips with other connectors. 2 of them are solid however the 3rd snapped right off when I touched it....

What does the level sending unit usually cost?

someone did a write up on how to get a 2g sending unit guts to work in a 1g sending unit and good luck finding a new one i called every auto parts store within 300 miles looking for one thay dont make them ne more lol

In theory any 3 wire universal sending unit should work should it not? Provided of course its the correct length and is the right size? I do believe its a standard 5 bolt set up correct?

I'll look around up here, if not I may just spend the rest of my time with her guessing until I can find a good one on here.

I'm sure someone has Retrofitted something to make it work...

Mazdatrx used to have them new. I replaced mine with a universal one and matching aftermarket guage. I have yet to find a aftermarket sender that has the matching ohm range for the stock guage. It is possible to have the low fuel light work and the guage not.

So my best bet is to find the closest Ohm rate I can with a univeral? How deep is the FB tank? The universals are set up for 6"-24" and from what I've seen you adapt them to fit?

just place a WTB thread in the classifieds for a used one

I opted for the aftermarket guage because I was changing/adding everything except the speedo and tach. Unless you're willing to add another guage, find a stock one.

Dealer item, about $100....don't mess with anything else

When you remove it, take note of the orientation of the float!

6 bolt actually i just took mine out last night and there its a 2 blade connector yellow wire is to the fuel gauge black wire goes to ground and the whole unit is griunded to the tank via the 6 screws

When it comes to the aftermarket guages, senders are matched to the guage. There are 3 different ones, each of which coincides to one of the big 3 automakers. None are even close to the Mazda ohm range.

hey i was lurking in da archive and i:icon_tup: found the write up on how to fix you sending unit

https://www.rx7club.com/1st-gen-archive-71/fuel-how-repair-fuel-level-sender-786986/

Sadly this doesnt apply to my situation, the connectors on the top of the unit have completely fallen appart so I'll need to get a new unit entirely.

Thanks though :)

I was in the same situaton and I broke the plastic around the portion of the remaining broken clip and fanageled a female connector onto it.

There has to be SOME way to still attach voltage / proper wire to the broken clip...

Or when the ground contact completely rots off and you connect the ground wire to the ground of the sending unit and it has a mind of its own lol Too much of a pain to mess with the wiring, either I'm going to buy a whole new fuel sending unit with a new connector that connects to the unit or just not know what my gas level is and always fill my tank to the top every day or two.