Lotus Elan and Lotus Elan Plus 2 Forums

Having only recently got my TwinC going again, I have yet to acheive a successful charging circuit. The ignition light remains on and the battery eventually discharges unless I charge it manually. Having taken a look inside the control box, I can see that neither of the arms move when the engine is running (I think one is supposed to oscillate, the other just closes?). I have checked all of the wiring and good connections are made. Is my dynamo stuffed, and how can I confirm this? Or is it likely to be something more challenging in the control box?

Best to read the Lotus Manual. There is all the info for troubleshooting the electrics in there. You might consider upgrading to an alternator though.

I couldn't agree more, unless you "MUST HAVE IT ORIGINAL" an alternator is the way to go, dont waste your time with that generator.
Brian

Oddly enough-the same dynamo as is on my Lotus is on my 1966 Ford 3000 Diesel Tractor (also made in the UK and shipped to the US)-excpt it has a mechanical tach takeoff on the back end of the armature shaft. 'Bullet-proof' is a word I'd use to describe it. The tractor takes a pounding - literally - and sits out in sub-zero weather. ALWAYS charges just like it's supposed to. It's gotta be something pretty simple. Follow the manual - especially the part about grounding the dynamo before attaching in the regulator. If you didn't properly ground the case - it won't work. (Takes 30 seconds) If you don't have one- get a cheap voltmeter and start checking outputs at various points. The regulator is quite easy to adjust also (adjust rpm at which it cuts in). I see that some suppliers now sell an alternator that looks like the stepped case generator externally - from the UK car mags I get occasionally. Think it's Moss Motors - but they are pricey.
Good luck!
Paul Zimmerman
65 Elan S2 (26/4600) and 66 Ford 3000!

Well I've been following the manual diagnostics and have discovered that the dynamo works just fine. Turns out anything up to 30 volts at high revs with the output connectors wired together.

Have been looking at the regulator and cut-out, the latter of which does not move to close the circuit at any voltage, and the regulator arm is similarly static. Done all the diagnostic tests, but they seem to imply a level of efficiency not present in mine - ie, the point is to check the voltage at which the cut out operates - but it won't operate at all. I haven't yet tweeked the adjusting screws, but will do so tonight and see what transpires.

I that doesn't work, the manual doesn't help any more and I can only conclude that the regulator and cut out are defective. Have checked the car's fuses (all 2 of them) and they are fine.

Thanks for your help.

Matt

The generator is solid no doubt about that!. What you're forced to also use is the old contactor type voltage regulator. It's the sparking contacts where all the problems originate from and why the alternator now rules. The alternator's voltage regulator is a solid state type and usually incorporated onto the backside of tha alternator housing. It's placed there because the cooling supply of fresh air flows into the backside and out around the pulley. The Elan is much better off with at least 60 amps from the charging system. At night the headlights are noticably brighter.

BTW, if anyone is having the battery drain down over a few weeks time for no apparent reason and you've got an alternator. That's usually caused by an alternator diode leaking current at or below the 300 milli-ampere range. The leakrate can be so low that doing the sparking test with a battery terminal will not show any. Any automotive Volt Ohm Meter will have a test mode for that fault condition. It's no big deal to replace a diode also.

I have fiddled with the regulator and cut out adjustment screws and have set the gaps, but to no avail. It seems they just don't want to work at all.

Keith, are you saying that with an alternator, I don't need the control box at all, or have I misunderstood?

That is correct. The voltage regulator is built directly into most alternators. I'll see if the web article on installing a bosch alternator in an MG is still active. If it is I'll post the link to it here later. Lucas also has some that will fit okay. You can buy the bracket that mounts the alternator at most of the usual places. I have a modified wiring diagram of the S1/2. Shouldn't be to hard to figure it out though if your car is different.

I know you are all right about switching to an alternator, and you have me convinved that I will. However, for now, I have fixed this charging problem with the purchase of a brand new regulator/cut-out control box directly from Lucas. Works a treat, and was a quick and inexpensive fix.

I am trying to get her on the road this week, although that now looks less likely. I am waiting for some parts, but the (well known in this forum) vendor has let me down with the delivery - should have come yesterday, didn't come today either. But until I get my new discs and silencer, I won't be able to re-assemble the car, let alone get an MOT

So near, but yet so far...

Been following this thread with interest as my S4 still has its dynamo. Seems to me that the deciding factor to convert to alternator must be whether or not you drive after dark much. I don't, in common, I suspect, with most other Elan owners these days whose cars (like mine) are pampered weekend show/nice weather/track machines, no longer used as basic year-round transport. Given that scenario, the dynamo (provided it's still working) is just fine.

Hatman raises a good point there. By far the highest current drawing thingies are the headlights. Generator is fine to power eveything else even if it's all on at the same time.

I'm hyper-sensitive to having the best possible lights because I drive deer infested roads at night all the time. Smacked into two last year ago just one week apart. Hitting a deer at 25mph does a lot of damage to an Elan. I was lucky it was a just a glancing blow off it's hindquarters because I only had time to slam on the brakes for the better part of a second beforehand. No brakes and it would have come through the windshield almost certainly.

Oh, deer!