Voltage Regulator behaving badly

[beachtrvlr]

Hi all, first post to this forum - have been a long time viewer, and have learned a lot just from perusing the great posts. Now, unfortunately, I have a reason to post a question of my own...

I've got a 1959 series II 109" 2.25 petrol, positive earth, LHD. I've had it a little over a year, and have had piles of fun with it so far. It is all original, but has a freshly rebuilt motor. It has been running like a top, no issues beyond the usual quirky things with old trucks...Some slow starting due to bad grounds, leaking Solex, etc.

Well, my general good fortune changed a couple of days ago, when out of the blue, sitting at an idle, the charge light came on, accompanied by a loud buzzing sound from the firewall. I assumed that I had broken a belt, but a tap on the gas made the charge light go out and buzzing stop. I drove home, and there was no light or buzzing above about 2k rpm. At home, I let it idle and lifted the bonnet. As suspected, the buzz was the VR. I popped the cover off, and discovered that the buzzing was caused by the "points" in the VR opening and closing rapidly, and arcing impressively when open. I stopped the engine, checked the belt for tightness - fine - disconnected the battery, and checked the face of the "points". Very pitted at this stage. Start it back up, and now the light is on at low idle, but no buzz (points closed). when slowing pressing the accelerator, the buzz comes on for a moment, then goes away when above around 2k rpm (points open). I am pretty mechainically inclined, but I don't know the finer points of how that VR is supposed to look/act on a normal day, so please keep that in mind for your explanation (dumb it down for me, please? ;-)

I've ordered a new VR from RN, but want to see if any of you have ever run across this buzzing/arcing phenomenon before, and know what started it. I don't want to roast another VR if possible! Thanks in advance for your input!

[LaneRover]

Never had that issue before but it sounds like it looked pretty impressive!

One of the nice things about having the old Rover regulator is that when you start working on your vehicle and you don't know any better and arc the alternator then it doesn't matter because it is still externally regulated by something that isn't ruined by a wee little spark!

Brent

[greenmeanie]

I can't tell you outright but mechanical regulators eventually wear out much like points. I assume you have the original alternator and regulator? If so the best thing for long term reliability is to ditch them in favour of an AC Delco 10SI. It's rather fit and forget.

If your system is a 3 wire with external sensing you could check that you don't have a ground on the sense wire as that will cause overcharging and will cook your regulator. In the short term my bet is just replace the regulator and all will be fine.

Cheers
Gregor

[beachtrvlr]

Thanks for the input - sounds like my plan to replace the VR isn't too far off track.

Greenmeanie, I have the C40 generator on the truck - it has been rebuilt and is in good shape. The VR may or may not be original - it is a Lucas, but doesn't look particularly new or old. I don't want to put an alternator on it; trying to keep it as original as possible. Question: how do I tell if I have a 3 wire external sensing setup?

Thanks again for your advice - very much appreciated!!

Justin

[Terrys]

You don't have 3 wires. With the original Lucas generator, you have a field wire and an armature wire. The generator Shell is grounded via it's mounts. The Lucas regulator went through several design changes, but they mostly involved the case, and hookup method. There are a few people who rebuild them. Look in Hemmings. They are pretty bullet proof, and the only drawback to the whole system is simply not charging at Idle, and their max current output is about 35 amps. If you've already ordered a new regulator (ouch) and you're not running a bunch of driving and fog lights, or any other accessory items that drag the battery down, you'll be good for, oh, roughly another 40 years. Only two things kill them; studipity and age. Age chews up the contacts over a LONG period of time, and moisture can rot out the dropping resistors on the back of the unit. Stupidity comes in so many disguises, but notably, the one where Jump-starting another, or yourself, and you get the cables reversed. Oh yeah, there was the guy who thought he would clean the contacts while the engine was running, and used carb cleaner, but then, the regulator was the least of his problems after that.