| Author | Message | ||
     Randy Roberson Grand Master Username: wascator Post Number: 607 Registered: 5-2009 |
I'm getting ready to finally get my fuel gauge working. You might recall I found the sender in the fuel tank in terrible condition and replaced same; alas! still no response from the dash gauge. I understand there is a voltage control unit that steadies the voltage to the gauge system: where is it physically located? My sender was in such bad condition and for so long, possibly it damaged this or another part of the gauge system. If someone has successfully dealt with this fault, I am interested in your experience. | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 67 Registered: 7-2015 |
Hi Randy Have you any voltage at the gauge? with the ignition on Mike | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1424 Registered: 6-2006 |
If you earth all the wires at the sender , the gauge should read full. One is an earth, one puts the fuel light on, the other the gauge. Does it change if you press the oil level switch? | ||
| Randy Roberson Grand Master Username: wascator Post Number: 608 Registered: 5-2009 |
I have to access the back of the gauge to check for voltage. Paul: As I recall earthing the wires made nothing happen; nor did the oil level button. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1425 Registered: 6-2006 |
Randy, the gauges are also prone to sticking in the zero position. Earth the cables by the sender and tap the gauge glass with your finger tip. Even cars in regular use suffer from this. You can check the wires at the sender for voltage as well. | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 68 Registered: 7-2015 |
Hi Paul I second what you say about sticking needles mine was stuck on 0 but pressing the oil level button and tapping the gauge made it jump into life. I think you will end up needing to get to the back of the gauge. Best of luck Mike | ||
| John Kilkenny Prolific User Username: john_kilkenny Post Number: 229 Registered: 6-2005 |
Here is a diagram I made some time ago to show the operation of the Shadow 1 oil and fuel gauge.  | ||
| Randy Roberson Grand Master Username: wascator Post Number: 609 Registered: 5-2009 |
The diagram and suggestions are most helpful; thank you all! | ||
| Randy Roberson Grand Master Username: wascator Post Number: 610 Registered: 5-2009 |
NEW INFORMATION: during my garage time this afternoon, I checked the fuel gauge: it does in fact respond to the oil level inspection button as it should: a somewhat slow but smooth motion toward the full indication. That is a plus I think. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 623 Registered: 5-2009 |
I'm back on the Fuel gauge: 1. It responds normally to the oil level function; 2. with a VOM, I have just over 10 Volts at the right sender terminal/wire, just over 5 volts at the left terminal/wire. 3. If I earth the LEFT harness wire to the sender, the gauge goes to FULL; 4. If I earth the RIGHT wire, the LOW FUEL lamp illuminates 5. I think the tank is actually about 1/2 full. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1452 Registered: 6-2006 |
The sender may be seized or the resistance coil or wiper may be corroded or faulty in side. Get a pair of gaskets and take the sender out and make shre it moves freely. Watch the gauge and see if it moves at any transmitter position. If nothing at all Take the top plate off and have a look inside. I would double check the warning light wiring and also make sure that the terminals are not just crimped onto the plastic and the copper has corroded away inside. (A tug) The rest is just for the bored . . Sticky gauges can be expensive. I had a parts customer who emailed me over a period of 3 months with a few weeks gap between asking for 2 dizzy caps. Ht lead set 2 x coils. Fuel filter Two fuel pumps Crank sensor. Various relays Throttle position sensor Eventually he got to engine ecu and 2 x ignition amplifiers. I said that it was unheard of for all of the parts to be faulty unless possibly somebody had boost started it backwards with 24v ? He told me that the auto electrician (non R-R) was highly recommended and insisted they must be the problem. He said it had never been boost started. It had not been out on the road for a few years but had driven in working perfectly and had been started every 6 months and run for a while wit out amy problems. Always started perfectly. Have you got fuel on it? The electrician said yes. It must be the ecu. I sent wiring diagrams and the test proceedure documents. After another month or so the Electrician said that the wiring was all good but so it must be the ecu. I suggested he had it transported to me, I would try a slave ecu and offered to discount the transportation price off a new ecu if it was faulty. It turned up unannounced about a month later. Checked her over. I'm sure you've guessed the happy ending . . . I added a couple of gallons of fuel and she fired up and ran perfectly. It was just he fuel gauge transmitter stuck at 1/2 full!! | ||
| Bob Reynolds Grand Master Username: bobreynolds Post Number: 360 Registered: 8-2012 |
Funny story.  Of course, when an engine doesn't start, there are only 2 things to check: Ignition and fuel. So why this took 6 months to find out, I can't guess. | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 94 Registered: 7-2015 |
How can these people call themselves electricians? Makes me angry  I spent years training to be auto-electrician which included 1 year mechanicals . some people change a bulb and call themselves auto-electricians GRRRR I bet if he had paid him $000's for parts he would have said oh yes they were faulty Mike | ||
| richard george yeaman Grand Master Username: richyrich Post Number: 464 Registered: 4-2012 |
The clue might have been the noise of the electric fuel pumps. Richard. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 624 Registered: 5-2009 |
The sender is new: a generic Smith's unit which is designed to be adjustable to fit different applications but otherwise identical to the completely faulty and corroded original I removed. Tests indicate the gauge should work as far as I can tell: the resistance from the sender seems right, etc, but alas! | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1453 Registered: 6-2006 |
Generic and RR often don't mix.  Is the sender well earthed? How is the sender adjusted? Have you tried it unfitted. ? | ||
| Randy Roberson Grand Master Username: wascator Post Number: 625 Registered: 5-2009 |
The only adjustment is the length of the float arm. The float itself is the identical white plastic part. The earth I used to confirm the gauge is the one attached to the sender base. I will fiddle with it more today and report back. The old sender was in such bad shape I knew it would not work once I saw it so I installed the new sender before I connected the wires. If I can't get it to work I will drain the tank and remove the sender. The resistance I measure seems reasonable though. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1078 Registered: 5-2012 |
Randy Why drain the tank? When I was working on my sender I first made a cover from some 1/16" steel plate. This allowed me to reseal the tank and use the car whilst I was repairing the sender unit. It also prevented inflammable fumes escaping from the tank. Geoff | ||
| gordon le feuvre Prolific User Username: triumph Post Number: 103 Registered: 7-2012 |
Sometime in the '70's I remarked that lots Shadows were suffering from the fuel gauge sticking on zero when ign. on. The reply from the R-R rep.when visiting our dealership was- bang top of dash. "it worked on the bombers when we were setting off on a mission in WW2" he told me!! | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1454 Registered: 6-2006 |
If leaving finger printd on the fuel gauge glass gets to you . Often is the stop pin that is the problem. To stop it making an infuriating tick noise when you turn off the ignition it is coated in rubber sleeve. The sleeve gets sticky so the needle can nit get aeay. You can try painting the stop with nail varnish to coat the stickiness.  | ||
| Randy Roberson Grand Master Username: wascator Post Number: 626 Registered: 5-2009 |
The gauge needle does not appear to be sticking: it works very smoothly when checking the engine oil level, also when I earth the appropriate wire at the sender. The sender is mounted about half way up on the rear of the tank: gas will come out if I try to remove it without lowering the level. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 861 Registered: 5-2015 |
Neither the fuel gauge or oil level work fast on my car. I had a similar thing with a Mini. The electrical system is about as simple as it gets. An electrician had fitted a new coil then leads then dizzy cap. I put some petrol in it and it started right up. I wonder at the incompetence of mobile services. How can you miss no petrol. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1455 Registered: 6-2006 |
Geoff many USA spec cars had the tank behind the rear seat like Spirits. I'm guessing that is why the tank needs draining. Randy, indeed we know your gauge is working, sorry, Gordon and I rambled of topic there for a while :/ | ||
| Randy Roberson Grand Master Username: wascator Post Number: 628 Registered: 5-2009 |
I sent a question to the vendor from whom I purchased the Smith's gauge sender. Maybe this will get resolved soon. Looks like the sender itself may be off. I did verify the earth connection is good. I don't mind the ramble; it lets me know you all care! | ||
| Randy Roberson Grand Master Username: wascator Post Number: 629 Registered: 5-2009 |
Fuel gauge problem is diagnosed I think: my new genuine Smith's sender seems to be defective. Sheesh. I did not test it before installation. |
