fd fuel gauge not working

[capella re]

need some help fellas. my fuel gauge hasnt worked in my fd since i got it, first thing you look at when you get in a rotary is the fuel gauge so i knew it wasnt working when i started it for the testdrive.
now heres the thing, just trying to narrow the cause down a bit. i would have fixed it sooner but two weeks after i bought it i was driving along and the "low fuel" light came on which was handy so i could get out of trying to fix it for a bit longer.

heres what i know
-the gauge sits on empty all the time never moves spikes nothing
-low fuel light works (i would assume this means the float is okay?? unless low level fuel indicator is separate, anyone know??)
-the guy reckons it was working until it came back from the engine rebuild with mildrens in which case engine had been removed, new fuel pump put in so could be anything (or he could be lying and forgot to connect it when changing the odometer readings!! seemed like a genuine guy so id be inclined to take his word for it though)
-i heard theres a ground on the centre housing top of the motor which will directly affect the fuel gauge if not reconnected, but buggered if i can see it down there

so what do you think?? power or ground not been reattached?? float been knocked?? and if you suggest something like a wire, let me know where it is as i dont have a manual and my internet is the step above 56k so i havent downloaded the pdf off here (that and its easier to ask for help than get off my ass :) )

i pulled the cover to the fuel sender off in the hatch area and the wires (from what i know, never seen another fd setup before) everything looks okay
any joins (plugs) half way down the car i should check??
ps unfortunately i dont have a multimeter either but il just check for circuits the old fashioned way if need be

thanks for your help in advance, and its not urgent due to having the low fuel light still operational but auto elecs aint cheap so if i can suss it myself would prefer that option

[FDTRX7]

Hey Simon,

I've got the manual and can give you a hand looking at what the problem is. After all, the fuel gague in mine works, if all else fails, we can reference mine and see what's different on yours to stop it from working.

[FDTRX7]

I've taken a look around and found a Full Colour Wiring Diagram Doc over at FDRX7
That's got what you're looking for :)

Post: FD-RX7 Enthusiasts Forum

Download Link: http://www.wrex-racing.com/html/fd/9...ng_diagram.zip (http://www.wrex-racing.com/html/fd/9...ng_diagram.zip)

[capella re]

I've taken a look around and found a Full Colour Wiring Diagram Doc over at FDRX7
That's got what you're looking for :)

Post: FD-RX7 Enthusiasts Forum (http://www.fdrx7.com/forum/showthread.php?t=1843)

Download Link: http://www.wrex-racing.com/html/fd/9...ng_diagram.zip (http://www.wrex-racing.com/html/fd/9...ng_diagram.zip)

thanks for that damo. i saw there was a guy with a similar prob to me over there on fdrx7 but his sender was faulty. tried to download the wiring file but said it was corrupt or something so thats not going to work.
due to the car having major engine work done to it and the gauge dying at the same time id find it a bit much of a coincidence so im putting my money on something not being connected or some wiring damaged. what would really help is if someone could let me know where the ground points are and which fuse/relay it works off so i can just check it off.
traced the wire inside the car (without removing rear seat) and seems okay, no excess pull or connectors to no where. back of the gauge looks okay (from looking under the dash, didnt go through hassle of removing facia / cluster.)

never had a prob with a fuel gauge before hence why i have no idea what im doing-even had to read how a gauge works for a starting point!! from what ive read sender should be fine due to low light coming on.

[The Stig]

http://www.fdrx7.com/forum/manuals.php

[vortex]

S8 clusters come up from time to time Simon so you might be able to pick one up and try that.

Perfect time to put in a 300km/h speedo, too! :D

[capella re]

http://www.fdrx7.com/forum/manuals.php

thanks dave

S8 clusters come up from time to time Simon so you might be able to pick one up and try that.
Perfect time to put in a 300km/h speedo, too! :D

still hoping its not a cluster problem and just a ground / fuse problem. really like the white faced cluster with the chrome bezel in 01 02 fds (not sure if its a special model) but so could not be screwed explaining a cluster change to a prospective buyer even realising it could have already been done.

just a couple of questions, does your fuel gauge show fuel level when ignition off or activates after key turn.

is there a fuse that would directly affect the gauge - i've been through about 30 fuses just incase i missed one. i read about the voltage probs on the back of the cluster but it affects the temp gauge too and mines fine only fuel level affected

and the two wires off the sender do they ground anywhere between the sender and gauge or if i do the test to check the float (bridging the two pins on sender clip) and the gauge still doesnt move am i looking for a clip that not plugged in rather than a missing ground to the body.

just trying to cover my bases save pulling pump and cluster out for nothing. thanks again for the help - i have searched this on rx7club too and its always been the float at fault but no one has said their low fuel light still works hence why i think the senders still okay.

[gotorx7]

Fuel level shows even with the battery disconnected!

[vortex]

really like the white faced cluster with the chrome bezel in 01 02 fds (not sure if its a special model)

White faced clusters were standard on all Version 6 cars.

[capella re]

Fuel level shows even with the battery disconnected!

thanks dave, due to the ground giving the read no doubt.

look, one last question and il leave you all alone. ive done the pin test and as expected the low fuel light works on grounding, needle doesnt. this would indicate gauge at fault BUT the low light and level travel on different goups down the side of the car. the needle goes with the red and the level wire goes with smaller speaker wires which suggests they dont just plug as one to the back of the gauge.

where does the needle level wire go?? straight to the back of the gauge?? or via the ecu or what?? if its straight to the gauge i need to double check its plugged in at the back the dash or if it joins somewhere else first i may have a disconnected plug somewhere. (maybe cluster maybe a plug)

least i know now, ruled out the sender for now. (provided sender and gauge didnt go at the same time)

thanks again

[Kotter31]

mine doesnt work either, when i can be bothered i was just going to get a spare cluster from katie and slam that in and see what happens but sounds like i have the same prob as you so maybe you can do all the hard work and ill just fix mine after hahaha

[capella re]

sounds like i have the same prob as you so maybe you can do all the hard work and ill just fix mine after hahaha

thats alright thats how these threads work, just everything i read either makes no sense or theres something i rule out to help me. im going to have to bite the bullet and pull the cluster out first and check the plug at the back then ground it to see if the gauge is stuffed and if its not either run a new wire to sender or strip the hatch trim rear seats and scuff panels to trace the wire and see where its unclipped.

its been a long day, lots of tools thrown and swear words yelled and my back hurts from lying upside down looking under the dash for relays fuses cut wires and as usual theres hundreds of them. il let you know how i get on when i pull the cluster out.

[Kotter31]

if i was you the first thing i would do is cluster out new cluster in

that way its ruled out straight away.

PS i know where some are

[capella re]

hindsight is a wonderful thing. only thing holding me back on this was lack of knowledge on fuel senders. if i did this again, i could get to where im at know in 30mins not 6 hours.

no point checking fuses, runs on ground not power. resistance comes from a power supply regulated to low voltage which is the same reg the temp gauge works on it would have affected both not just fuel.

low fuel light still working elliminates fuel sender being a problem, needle and light work off same sender just volt regs are different hence light only works at a lower reading.

cluster can be tested by grounding at rear to eliminate or find the gauge to be your problem also use a low voltage source to check as well, sending 12v straight to the cluster would damage the unit.

and for farks sake, check the wiring last. 5000mm of wire to go through to look for 1mm of damage. i bow my head in shame for attempting to look for a dodgy connection first.

I PITY THE FOOL THAT LOOKS FOR DODGY WIRING FIRST SUCKER!!!!!!!

http://farm1.static.flickr.com/163/398422382_5153133f8d.jpg