Fuel Level Indicator
 

Hello everyone,

So I finally got some new tires for my FB and with the prospect of driving it more regularly, there are three small issues that I feel should be addressed:

1. Fuel gauge doesn't work
2. Windshield chips
3. No lighting for gauges

Number 3 only affects me for night driving (maybe I'll just stick on an LED keychain or something), number 2 is mostly a preventative measure and I might try one of those rock chip repair places at the mall, but...

I don't have much car maintenance knowledge (though I am a bit mechanically inclined and own some tools) so I don't really have any idea on where to start tracking down the fuel gauge issue. Is there something RX-7 specific I might look for or should I just google how-tos for cars in general?

My first assumption would be to check the fuse to it. Then let me know and i can try and think of Some other stuff.

My fuel gauge didn't work so I unplugged it and cleaned the crap out of the contacts. Now it works fine.

I was going to start tracking down this issue after work yesterday but I wound up falling asleep until after 9 pm instead.

Thanks for the suggestions, I'll dive into this this afternoon! (I hope)

Is it stuck in a certain position? Like dead empty or pegged out full?

It's stuck at about 80 percent

Not sure if they're all the same for the first gens but when I looked at mine it had a tiny little pin that would pull up on the actual red needle that you see and it was kind of sludged up and grimey. I had to clean it with a q-tip for it to move freely. Then theres a small box on the back with a transistor in it and a small circuit board. I cleaned the terminals on all that too and between the 2 simple repairs mine worked properly. You can carefully remove the one pin from the drivers side connector that goes to the fuel level sensor and measure the resistance to ground through it to make sure it even still reads. If it does...dump a few gallons of fuel in and the value should decrease if its the same as my '79. Mine reads like 80 ohms full to 5 ohms empty. If thats good turn the key on with that one pin still out of the connector but the connector properly installed in the gauge cluster. The fuel gauge should go to empty. If not the gauge is stiff or the little voltage reg/transistor box is bad. Hope this helps

Forgot to add but...would do these checks after checking the powers and grounds first. Be surprised how many times you will find a simple broken wire behind a dashboard. Be the cheapest fix too

sorry I haven't posted in a bit, but I'm on leave now so I have more time to focus on fixing stuff. Looks like this was the culprit, but one of my prongs has melted off and attached to the female end... :banghead:

Now what? Is there somewhere I can buy a new pair?

Attachment 499120

Attachment 499121

The right way to repair that so you only have to do it once is to replace the level sensor as a whole unit and soldetin in a new connector. If you want to save a few dollars and you are confident with your electronics skills you might be able to solder something to the top of the original sendor there, still removing the gas first and working on a table away from any open fuel so you dont burn your house down. Would be a way to make it work but wouldnt be right. I prefer the new replacement idea. Online someone may have what you need for sale also. Hope this helps.

Typo sorry. SOLDETIN = SOLDER IN

What is the nomenclature for the connector? I found the fuel gauge sending units and they are unfortunately about 130 but oh well!

If a mazda dealer cant supply any real answers then you can use regular size "spade" terminals for it. If the outside of the spade terminals arent encased to make sure they dont contact anything and short out, put heat shrink tubing around each individual terminal end. Hopefully after this tepair you have no more issuea. If something shorted out prior to this it might have caused damaged to something else but...have to fix the obvious first and go from there.

Im terrible with typos :( sorry. TEPAIR = REPAIR

Alright, sent an email to my local dealer. Hoping it doesn't come to soldering or I'll have to learn how to do that (luckily, I have someone near-ish that is proficient and can show me)

Its very easy to learn and is good to know for further issues. Gonna need it one day lol. Hope the problem is fixed with the one repair so you can move onto the next.