Hi folks, I'm after a bit of advice on a battery charging problem. This is the situation, I've got a 1600 beetle engine in my bus with a dynamo. She runs pretty well and we get around at night with the lights and wipers on, then every so often we go to use her and the battery is flat (she isn't a daily driver - yet). I live near a battery specialist and got them to check it once I'd charged it at home - they said it was all fine. Next up I checked the draw from the battery which was about 110 milliamps so I'm pretty sure nothing's sucking it dry. Now I'm thinking it's either the dynamo or regulator, I did a couple of tests from the Haynes manual and found that the 'no load regulated voltage check' returned 12.4V at high revs instead of 13-14 as suggested and the 'current output check' was a bit weird as my multimeter showed 0.03A at high revs. We were out in her yesterday and late last night, so the lights were on (mostly full beam) and the wipers were going and at times I could see the charging light glowing dimly but not all the time and you'd never see it in daylight it was so dull. Before we went out the battery was showing about 12.5V, this morning it's showing about 11.8V (but still started fine). I'm fairly sure that if I replace it all with an alternator all will be solved but if there is a cheaper method I'd be interested to hear it. Also will I be able to put an alternator onto the beetle engine (I believe it is a 1973 engine), I know I will need a new stand and backing plate but is there more I need to bear in mind? Having searched the threads I know it can be done in situ but I'm wondering about fouling the carb (a pict 1) and whether I could use the existing fan? Any help and advice gratefully recieved. Many thanks, Adam.
have you checked the brushes ( 2 of them ) as they might be worn , about £4 for a new set , mine had on and off chargeing changed the brushes and all was fine again , also had a tempremental regulator in the past with similar issues , there not so cheap and about £40 , just visually look at the 2 brushes see if there warn down or not My dynamo light sometimes glows slightly of a night when ive got everything on but has never caused any problems and mine isnt a daily think the last time i checked at high revs mine was kicking out just shy of 14v
Thanks, I'll give them a look. I had thought of that before but don't really know what I'm looking for, I suppose it should be pretty obvious if there's not much of them left!! That would certainly be an easier solution than replacing the whole lot...
look like 2 thin lego bricks ! these http://www.ebay.co.uk/itm/VW-Beetle-Camper-Dynamo-Brushes-Set-12v-NEW-Brush-Set-T1-T2-Bug-Bus-Van-Kombi-/120948140988?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c29122bbc
Thanks. I've checked and there is plenty of lego brick left! What is a bit embarrasing is that I also noticed that the fan belt is loose, it still turns the pulley but I could twist it through 180 degrees. I only tightened it about 3 weeks ago so I think I need to fit the spare and have another check before I chuck everything out. I should have checked that first but didn't because of its recent attention.
Just a quick update. I fitted a new belt (the old one was for an alternator) and even though it's all set up nicely the dynamo results are the same. I'm going to take the dynamo off soon and see what's what. A friend of a friend has recommended a local place that might be able to fix it for about £35 so I'll let you know if it goes that way.
Hmm. After not charging very well even though the light went out, I was aware I should sort mine. The brushes didn't look too worn. Then the light came on and never went out again. When I took the dynamo out, pieces of twisted commutator fell out of the end and one of the brushes was snapped in two. I swapped it for an alternator. You'll need a new stand for it if you go this route, but the wiring is simple enough.
Thanks for the help. Here is what happened in the end; I replaced the dynamo with a new one from my local motor factor (£60 + VAT) and then despaired as my multimeter told me I was getting 0 volts. Then the probe fell off the positive lead and so that got fixed to find that the dynamo was putting out plenty of volts but I wasn't getting any at the battery. I took the regulator off and had a look under the cover - it was obvious it was in a bad way, one of the points was blasted apart and blackened, the other was 'welded' together with a blob of solder. I got a replacement from machine7 which arrived the next day and now I'm getting a healthy 14 volts at the battery. I took the old dynamo apart and it looks fine, good separation of the commutator segments and they were nice and shiney, no scoring or anything. The wires were well connected and the windings didn't look in a bad way at all, so I suppose we'll never know why it wasn't working. I left the engine in to take the dynamo off. I didn't raise the fan shroud as I was a bit paranoid about the flaps not working if I didn't set it down right and I have no idea how it's supposed to feel to know if they're trapped or not. I took off the carb and air filter and removed the nut at the back of the fan shroud (36mm socket and a bar about 16" long). I needed to tap it with a hammer (the bar) to get started but after that it all went quite smoothly. I just left the fan in the shroud. The bosch woodruff keys were much better than the ones I got with the new dynamo so I used them again. It was tight getting the pully onto the new dynamo too, so I took a bit of metal off gradually by running a bit of old sander belt around the inside of the pully and on the shaft until it would go on with gentle taps from a hammer. Oh yeah, I took the regulator off as well as it was in danger of getting clouted with the bar when getting the nut off. And the lower backing plate nuts were a real pain to get back on, not so much the right hand one but on the left behind the manifold took many, many attempts to get back in. Hopefully this might be handy to someone else in the future.
