Page 1 of 3

Fuel gauge now working

Posted: Wed Jul 04, 2018 7:52 pm
by Caprifan Rob
Capri passed the MOT today, fuel gauge was working fine on the way down, wasn't working on the return drive :banghead: .
Checked connections on the sender in case they dislodged something but all ok, don't want to remove dash if I don't have to. Anyone have any suggestions where to look, if it's fused, is anything else on same fuse?
Thanks in advance, has been working fine for last few years.

Image

Re: Fuel gauge not working

Posted: Wed Jul 04, 2018 8:29 pm
by Andrew 2.8i
Hi Rob,
Great result with the MOT!
Obviously it's a foregone conclusion with a car that is as immaculate as yours. Which looks superb, by the way. 8-)

The fuel gauge is on fuse 7, the same as the hazards, indicators and dash warning lights.
The temp gauge also works off the same voltage regulator as the fuel gauge, so if the temp gauge is reading OK then the regulator will be working properly.
The fault could be with the wiring coil on the part of the sender inside the tank.
If you need one, I noticed that Martin is selling brand new repro senders on Ebay.

Andrew.

Re: Fuel gauge not working

Posted: Wed Jul 04, 2018 8:48 pm
by Caprifan Rob
Andrew 2.8i wrote:Hi Rob,
Great result with the MOT!
Thanks very much Andrew, I'll have a look at your suggestions tomorrow. Bloody annoying as I was looking forward to another year of fun & it's a pretty vital gauge :D
Funny for it to just stop working with no warning.
Cheers,
Rob

Re: Fuel gauge not working

Posted: Wed Jul 04, 2018 9:23 pm
by Jasonmarie
Glad to here your stunning Capri passed the mot with it up on the lift I wonder if they caught the lead down on the sender unit as Iam sure there should a earth lead down there on the tank end ?
Hope you get it sorted :beer:

Re: Fuel gauge not working

Posted: Wed Jul 04, 2018 9:50 pm
by Peter-S
My first thought is the earth. Try connecting a good fresh earth to the sender to see if the gauge works. If it does then trace the proper lead back and clean the connection. I think it might be in the boot.

Re: Fuel gauge not working

Posted: Thu Jul 05, 2018 5:09 am
by Andrew 2.8i
A poor earth is a good shout.....when Rob mentioned that he had checked the connections, I assumed that included testing them with a multimeter. I should stop assuming!

Andrew.

Re: Fuel gauge not working

Posted: Thu Jul 05, 2018 6:29 am
by Caprifan Rob
Thanks for replies, I only had time yesterday to remove & replace the sender unit wires. Didn't use a meter, thought it might have been something as simple as that. Will chase wires later & figure out what's going on. Cheers :cheers:

Re: Fuel gauge not working

Posted: Thu Jul 05, 2018 7:29 am
by andyd
Well done with the MOT, car looks great too :applaud:

Hope you sort the issue and it's nothing too awkward....Nothing worse than a dodgy petrol gauge :doh:

:goodluck:

Re: Fuel gauge not working

Posted: Thu Jul 05, 2018 9:02 am
by nigecapri
The gauge should move up to read FULL if the two wires at the sender are connected together. If they are corroded and need cutting back then a couple of bullet female connectors will do the job.

Re: Fuel gauge not working

Posted: Thu Jul 05, 2018 6:22 pm
by Caprifan Rob
andyd wrote:Well done with the MOT, car looks great too
:cheers:
nigecapri wrote:The gauge should move up to read FULL if the two wires at the sender are connected together. If they are corroded and need cutting back then a couple of bullet female connectors will do the job.
Connected them together & gauge read full, put meter on sender & found no continuity. Bugger, I guess a new sender is required then, at least I now know what it is.
Thanks for help.

Re: Fuel gauge not working

Posted: Thu Jul 05, 2018 8:07 pm
by Andrew 2.8i
Caprifan Rob wrote: I guess a new sender is required then, at least I now know what it is.
Hi Rob,
It's a bit of a bummer that you need a new one, but we shoud at least be thankful that they are available to buy new.

Andrew.

Re: Fuel gauge not working

Posted: Thu Jul 05, 2018 9:36 pm
by Bod9084
You can check the cinder by taking of the wire and sending a earth down to see if it goes up

Re: Fuel gauge not working

Posted: Fri Jul 06, 2018 9:23 am
by Andrew 2.8i
Rob,
Don't forget that a repair might be possible.
viewtopic.php?f=17&t=46894&p=322831&hil ... ir#p322831

Andrew.

Re: Fuel gauge not working

Posted: Fri Jul 06, 2018 6:32 pm
by Caprifan Rob
Andrew 2.8i wrote:Rob,
Don't forget that a repair might be possible.
viewtopic.php?f=17&t=46894&p=322831&hil ... ir#p322831

Andrew.
Thanks Andrew, I had the original repaired once & it's lasted around 3 years or so. I've bitten the bullet now @ bought a new one. Kids will have to go hungry for a while... :nopity: :)

Re: Fuel gauge not working

Posted: Fri Aug 03, 2018 8:43 pm
by Caprifan Rob
Just an update. Fitted the new sender unit today (a CCI unit, only one I could get) . Tested continuity before Fitting & I get a reading on the top 2/3 of its movement. Not having anything to compare it to, I fitted it as I've been running down the tank.
No reading showed on gauge after fitting but tank was really low, filled it up & reading went all the way to .. 1/4 of a tank!
Got a local meet I'm taking it to tomorrow, if nothing changes, I'll be emptying the tank & sending it back. Cost too much for it not to work properly. Has anyone else fitted one of these?

Re: Fuel gauge not working

Posted: Fri Aug 03, 2018 9:28 pm
by Peter-S
I think the feed on this is meant to be 6 volts, governed by the regulator in the dash. Might be worth checking what reading you are getting.

Re: Fuel gauge not working

Posted: Sat Aug 04, 2018 5:54 am
by Caprifan Rob
Peter-S wrote:I think the feed on this is meant to be 6 volts, governed by the regulator in the dash. Might be worth checking what reading you are getting.
Cheers Peter, I'll try that when I get back from the meet today.

Re: Fuel gauge not working

Posted: Sun Aug 05, 2018 5:56 pm
by Caprifan Rob
Peter-S wrote:I think the feed on this is meant to be 6 volts, governed by the regulator in the dash. Might be worth checking what reading you are getting.
Checked this & ive got less than 4 volts power. Does this mean changing the regulator as well to make it work or is there another reason for this? Sorry, not so clever with electrical side of things :) . Thanks, Rob

Re: Fuel gauge not working

Posted: Sun Aug 05, 2018 6:21 pm
by Andrew 2.8i
Caprifan Rob wrote:Checked this & ive got less than 4 volts power. Does this mean changing the regulator as well to make it work or is there another reason for this? Sorry, not so clever with electrical side of things :)
Hi Rob,
It's supposed to be 5 Volts, so it sounds to me like the regulator is not working correctly. The low voltage you have will affect the correct operation of both the fuel and temperature gauges.

The voltage regulator chip is cheap enough to buy, it's a 7805 that you need.
https://www.ebay.co.uk/itm/10psc-L78XXC ... X7805.TRS0

A guide to changing it:
http://www.capriclub2000.co.uk/help-inf ... mp-gauges/

Unfortunately, some of the photos appear to be missing, but at least the text is still there.

Instead of riveting the heatsink back in position, I used a small brass nut and bolt (M2 or M2.5, something like that).

Hope that helps.

Andrew.

Re: Fuel gauge not working

Posted: Sun Aug 05, 2018 6:50 pm
by Caprifan Rob
Andrew 2.8i wrote: Hope that helps.
It certainly does. Just ordered one as you suggested, thanks very much for the links :cheers: . I'll fit & report back when it arrives to see if that solves the issue. Thanks for all the replies :D