Faulty Fuel Gauge

I've given up on my readout ...It will read a level when switched on but will not count down until I'm almost out then goes from 8 galls to zero with warning light Disconnect the battery and it will reset to a new level but still will not show any drop

I've checked and tested everything ,the sensor works out of the tank,checked resistance at top ,bot and mid ..............so I'm now completely resigned to this method ....

Lee. You`ve got a manual, what model year is it for? and in the "under the bonnet" diag , does it show a TSU like Jeff says his does
John

I've not got a blackbox sender unit .It's an early setup ' 88 car .Checked the tank tube and it does what it should so it's whatever converts that signal for the digi readout that's at fault I feel .......

I've not got a blackbox sender unit .It's an early setup ' 88 car .Checked the tank tube and it does what it should so it's whatever converts that signal for the digi readout that's at fault I feel .......

Yes Lee, I know yours has not got a TSU, but I was wondering if your manual was different to my two, and showed item 593 that Jeff speaks about.
The only thing with yours is the continuity between the Sender and the computer. or the connector on the back of the computer. But a thought has just struck me.... does thr MPG work on your computer, as this does not need the tank level to compute. This might give an indication of the computer working at all

That reminds me ...I must reconnect the gearbox sender
I'll do that and see if the speedo etc works
I'll dig the book out and see .

John, I hadn't done the computer reset previously, but I have just come home and done it as you suggested. Unfortunately it has just gone back to the 18.7 gal. It is not flashing, but I assume as soon as the car is using petrol and the value drops, that it will start again.
To your other question, the rest of the computer display is working. It is computing the mpg and showing the mileage travelled and the tank contents are reducing accordingly? I have previously had speedometer problems, like evryone else, but it has been a liitle more stable lately. Yesterday I cleaned the earth at the bottom of the driver A-post and I am hoping that may also improve things - here's hoping.

My wiring diagram is for the years 1987-1988 and has a reference No NT 8038, so it sounds as if it is the one that falls in between your 2 ?
I am going to upload the image of the underbonnet area and the relay shot so that you can compare.

I take your points regarding your comments relating to the relays, but it has to be worth a try, It seemed to do the trick for someone else who responded, so if the relay is there it should be easy to check if it is working or not? I fully appreciate your points that they could be related to the fuel pump circuit, which would be more logical, but we are talking about Renault!!

The parts list Ref No seems to be PR1132 which is applicable to 1985 - 1989 and is something that I have had for about 10 years.
The plate reference for the tank sensor control unit is 83.101 and the item ref is (7), the part number is 60 01 018 982, the relays are shown in Plate No 87.401 and are items (6) and (19) and are P/Nos 77 00 764 239 and 60 01 052 001 resp.

I will get the reference numbers from the tank sensor control unit as soon as I get the chance to remove the boot liner again. Unfortunately I am away this weekend, so it may take longer than I would like,

Cheers,

Jeff
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[BIG_MVS]

It's a relay I'm tellin ya

From memory it's the middle one (VIGNAL)

How much ?

Martin...I hope for Jeff`s sake you`re right...that would be the best result. However I find it strange that Jeff cannot identify item 593 when it is quite clearly in the pic. It could well be a TSU but from what he said there is no reference to it in the manual. Nevermind, time will tell.

Jeff, can you post the cct diag of the Fuel Gauge from your manual here, and also the location diag of thr relays. I would like to see the what differences there are between the 3 versions. The strange thing is that there is two types of sensors, two types of instrument clusters which seem to go together, and yet there seems to be a strange cross over when they changed from one type to the other around `89.
I look foward to your getting the pt.No. of the sensor, and item 593 when you get around to it.
Cheers
John

John, I hope that Martin is right as well !! I think that I know where the relays are, although it has been a very long time since I looked in that area? It would be a much easier result than trying to find the relevant connector blocks in the various areas?

The sensor looks to be more of a solid state type than the conventional relay type and judging by the 6 terminals are feeding more than one circuit?

I will send you the wiring diagram and the relay page tomorrow. If I get a chance tomorrow night I may try removing the boot liner and get the details of the sensor control box, will let you know if I do.

When I get more time I will try and scan a copy of the wiring diagram

Jeff

[stephendell]

Strange.

Black box 593 is not listed in the list of components for the 87-88 diagrams which in fact stop at item 586, but it's clearly there in the picture.

It disappears from the wiring diagrams in 1989 and then returns again in 1990

The sensor looks to be more of a solid state type than the conventional relay type and judging by the 6 terminals are feeding more than one circuit?
Jeff

Jeff. When you say the sensor, I call the long tube that drops into the tank the sensor, and the box on the wing (Tank Sender Unit or TSU) the Sender. The unit you are discribing above I take it is the Sender, am I correct?, sorry for this, but it is important that we both are talking about the same things
John

Strange.

Black box 593 is not listed in the list of components for the 87-88 diagrams which in fact stop at item 586, but it's clearly there in the picture.

It disappears from the wiring diagrams in 1989 and then returns again in 1990

Thats what puzzeling me too, when the TSU returns it becomes item 327 in the 1990 model year. It will be interesting to see if the sensor in his Alp is the early or late one, considering his Alp has Red needles, suggesting that it is of the earlier type

Sorry John I am confusing you, I think I must have sensor on the brain!!
I meant to say relay in my previous post, referring to Martins previous picture that was showing the relay?

No problem Jeff....we`ll get there in the end