Hello again, Battling a million electrical problems... had an earth issue in the dash, the Rev counter would drop when lights are on. Realised there was a loose earth connector to the dash. Plugged it back in, sorted. However, now the fuel gauge doesn’t work. When I pull the earth, it works again. I’ve read through the cheat sheets and various other materials online, and can’t for the life of me work it out... I’ve tried: Adjusting the micro adjuster, now it’s maxed out and only slightly (about an entire tank!) accurate. Ensuring the regulator is flush with the dash Wondering if anyone’s got any suggestions? Should I replace the regulator? (Although a replacement is £30) Many thanks again! Sent from my iPhone using Tapatalk
As a starting point, I'd take off that ghastly piece of tagboard - God knows what's going on there. For earths, use the star point on the back of the pod. Pull off all those wires from the tagstrip, get your trusty wiring diagram and put any original ones - hard to tell which are which - back where they're supposed to be. Don't guess! Does your alternator light work? I'd avoid fiddling with the fuel gauge adjuster. Is the sender earthed at the tank end?
Looking at the bodgery again, the few tags in the middle seem to provide a positive supply...but they're shorted against the pod case, which may explain a thing or two when you connect the brown earth. Best to sort the whole lot.
Agree with all of that. It would be good to investigate the voltage stabiliser. What it does is take a voltage from the alternator/battery which varies somewhat depending on engine speed and whether you have your lights on, and leaks half of it away to earth, leaving a steady voltage to apply to the fuel gauge circuit. You should get around 5.2 V if you measure between the red wire and earth. The fact that when you disconnect the earth the gauge shows a reading suggests that the output from the stabiliser is too low. Mine went down to about 2 V so my gauge only went up to about 1/4 full. I repaired mine by soldering in a new zener diode (about 40p from Maplins when they were still in business). I did see a complete stabiliser on ebay for about £15 though.
Looking at that mess, I'd say the fuel gauge is probably fine, if the voltage stabiliser is properly grounded. The wiring looks original and as it should be. It's the rest that's the problem...
Thanks all. Ordered a service manual and I’ll see what I can put back. I think the tag was added to go to the Rev counter so I’m not sure if that’s after market or not. Weirdly since filling up, it’s now over reading the tank, which could possibly mean its back to normal minus me messing around with the fine tuner. I’ll take it all apart and have another look. Good spot with the high beam.. that’s another problem I’m trying to diagnosis. It too has stopped working recently!! Sent from my iPhone using Tapatalk
I promise you that bodgery isn't original (neither was a rev counter). There are neater ways of providing +12V for the rev counter. As an experiment, just unscrew the tagstrip so it doesn't touch the case. Things should improve. Get a coloured wiring diagram from the web, and reconnect wires that are original (only the black/brown as far as I can see). Where does the yellow wire go to? Short be easy to sort, although fuel gauge will need re-tweaking back what it was. http://www.vintagebus.com/wiring/
Ok so it seems to be reading the correct amount now that I’ve tweaked it again. I’ll need to empty the tank to properly know if that’s sorted. I’ve no idea how it’s put itself back to normal though.... In terms of the tagboard, here’s the top of it: The yellow reads tacho and heads off into the Rev counter via the solder, so I assume that’s the signal in. The mess of red and black is for the hand break light. I’ve still not solved the headlamp light issue though. It’s not the bulb. I’m getting 0.3v through when the lights are on so I assume it’s something further down the circuit. I’ve traced in back to below the fuse board where to heads into the transformer (I’m guessing) and that’s all connected up. I’m still getting current through on the dashboard lights though, so surely I could just daisy chain it onto the end of that? Sent from my iPhone using Tapatalk
have you disturbed any wires when you were doing your wiper motor. there is an earthing star point just under the wiper
Dont forget that headlight relays fill up with water leaking down from above and rot away, so absence of main beam may be because there is 2cm of water in the relay. I thought my bus came with a spare headlight relay.. until I unclipped the case and found rusty wreckage and a high water mark on the plastic.
Great idea. Pulling the motor assembly out seems to disconnect every wire under there. I’ll double check the earthing. The high beam lights actually work fine. It’s just the dash light for them that doesn’t, which I wouldn’t have thought would be affected by earthing for the high beams but worth checking over. Not spotted any water down there but I’ll have a closer inspection. There’s so many holes in this thing it wouldn’t surprise me! Sent from my iPhone using Tapatalk
