TwinCamJohn Posted April 2, 2018 Report Share Posted April 2, 2018 I was sat in the passenger seat today (LHD) checking a few things before the next rallye. On glancing to the left I noticed the ammeter wasn't exactly in the middle and was about the thickness of the white central mark towards discharge. I couldn't see anything that would be "on". I suppose I haven't noticed it before as from the driver's position it doesn't stand out; Any thoughts? Perhaps others have the same situation? Quote Link to post Share on other sites
RogerH Posted April 2, 2018 Report Share Posted April 2, 2018 Hi John, they are not accurate - don;t panic. If you want to centralise it, you could position a weak magnet near the gauge to tilt the needle over. Roger Quote Link to post Share on other sites
TwinCamJohn Posted April 2, 2018 Author Report Share Posted April 2, 2018 True, it's just getting to know your gauges ! I now know that the fuel gauge means empty when it is just under a 1/4 ! Quote Link to post Share on other sites
TorontoTim Posted April 3, 2018 Report Share Posted April 3, 2018 True, it's just getting to know your gauges ! I now know that the fuel gauge means empty when it is just under a 1/4 ! Ah yes - a useful thing to know, even if it's annoying learning it... Quote Link to post Share on other sites
Dave Larnder Posted April 3, 2018 Report Share Posted April 3, 2018 Hi John As your car is LHD like mine, I have reversed the small gauges so that you can see them better from the driving position. Top right I have the Oil pressure, and below it the water temp. gauge. This is because they are the two most important to view while you are driving. The fuel gauge(top left) and the ammeter if you need to check them, you can crank your head over to see them very occasionally, whereas the other two you should glance at them reasonably regularly. Hope this helps. Dave Quote Link to post Share on other sites
peejay4A Posted April 3, 2018 Report Share Posted April 3, 2018 Hi John, they are not accurate - don;t panic. If you want to centralise it, you could position a weak magnet near the gauge to tilt the needle over. Roger +1. Get a small neodymium magnet and stick it on the back of the dash panel. Move it around until the ammeter needle is dead centred and you can call it "compensated". Been there etc. Quote Link to post Share on other sites
TwinCamJohn Posted April 3, 2018 Author Report Share Posted April 3, 2018 Interesting idea. Thanks. Will have to look up neodymium Quote Link to post Share on other sites
john.r.davies Posted April 3, 2018 Report Share Posted April 3, 2018 Pete, would this work with a fuel gauge? I have a dip tube sensor, in a custom tank. It's at a slight angle and when the gauge reads zero, about five litres is left in the tank. And it reads full, when there's 5-10 litres of room left. But, the gauge is right next to the oil temp. Gauge (an adapted OE water temp gauge). Is just jiggling the position to influence one and not the other? John Quote Link to post Share on other sites
peejay4A Posted April 3, 2018 Report Share Posted April 3, 2018 It might work with a balancing coil type gauge John. It wont affect a bimetallic gauge as fitted to wind up window cars though. Quote Link to post Share on other sites
john.r.davies Posted April 3, 2018 Report Share Posted April 3, 2018 No idea of the operating principle. It's a VDO sensor and gauge, and while my Vitesse did have wind up windows once, not any more, so there's hope! John Quote Link to post Share on other sites
RobH Posted April 3, 2018 Report Share Posted April 3, 2018 Rather than poke-and-hope with a magnet John- this might help : https://sites.google.com/site/shannonpowerlab2/home/calibrating-your-fuel-gauge Quote Link to post Share on other sites
john.r.davies Posted April 3, 2018 Report Share Posted April 3, 2018 Wow! Thanks, Rob! Proper calibration! John Quote Link to post Share on other sites
peejay4A Posted April 4, 2018 Report Share Posted April 4, 2018 Solved then. A magnet wouldn’t work with that sort of gauge anyway, poking , hoping or otherwise. Quote Link to post Share on other sites
Z320 Posted April 7, 2018 Report Share Posted April 7, 2018 Plug off the battery and see what happens with the amperemeter Quote Link to post Share on other sites
John McCormack Posted April 7, 2018 Report Share Posted April 7, 2018 It is probably just parallax error. The needle is a small distance from the face so it will 'move' depending on the angle you are looking from. I always get a bit of a surprise looking at the gauges from the passenger seat as they all read differently than from the drivers seat. Quote Link to post Share on other sites
TwinCamJohn Posted April 7, 2018 Author Report Share Posted April 7, 2018 Plug off the battery and see what happens with the amperemeter Doesn't make any difference. I can live with it, and in any case it doesn't notice from the driver's seat ! Quote Link to post Share on other sites
Z320 Posted April 7, 2018 Report Share Posted April 7, 2018 (edited) Doesn't make any difference. I can live with it, and in any case it doesn't notice from the driver's seat ! Good plan, would also be my plan Edited April 7, 2018 by Z320 Quote Link to post Share on other sites
Charlie D Posted April 7, 2018 Report Share Posted April 7, 2018 I think the calibration page that Rob mentioned is a neat way of solving the problem of inaccurate readings. Just one comment. The guy says: Note: When you calibrate make sure that it is done when the engine is running at least 2000rpm and alternator is in charging mode. If not, the voltage variation will lead to inaccuracy and the indicator varies quite a lot between 12 ~ 12.4V from battery voltage alone vs 13.8~14.2V from alternator voltage. I don’t think you really need to bother with that as in most classic UK cars the instruments are fed via the 10 volt regulator, the whole point of which is to keep the instruments at a constant voltage, no matter what volts the battery is giving out. (As long as it is over 10 volts, of course.) Is that correct? Charlie. Quote Link to post Share on other sites
RobH Posted April 7, 2018 Report Share Posted April 7, 2018 (edited) You certainly don't need to for TRs which either have balanced-coil or stabilised meters as you say Charlie, and the same goes for any other makes too which use similar instruments. Of course what the chap did not say (although it should be obvious) is that such calibration will only work over the operating range of the tank sensor. If the physical movement of that is restricted before the tank is completely full or empty, you can't compensate by fiddling with the gauge. Edited April 7, 2018 by RobH Quote Link to post Share on other sites
Nigel C Posted April 9, 2018 Report Share Posted April 9, 2018 that's a good link about the fuel gauge adjuster. I did read the "other guys" page sometime ago about adjusting the slide screws on the back of the gauge which did improve matters but I still have a gauge that reads about a 1/4 when the engine starts to cough and splutter (much to the annoyance of the present Mrs C) and stays on the full stops for a long time when full. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.