My new, old, 1969 +2 and a battery/charging question

[CaveatLector]

Were 1969's originally a postive ground (earth)? It seems so by the way the wiring is set up on my Elan +2. Someone may have switched it over later on, but why?

Also, I get a whirring sound coming from my headlight housings. I haven't yet looked at it closely but does anyone else experience this? Could it be a bad solenoid? Also, my headlights pulsate. Obviously there is not sufficient power being generated or at least sent to the lights to keep them going full-on. Any encounter this?
Thanks in advance.

[types26/36]

I'm not sure when Lotus changed to negitive ground, sometime around that time, others may know better. The usual reason to change is if an alternator is fitted, does your car have an alternator ?
another reason is if a modern radio is fitted which are usually neg ground (some can be changed to either system)
Look on the face of the rev counter, it normally says if it is pos or neg, if it was converted it may show pos ground, of course if it were converted the rev counter may have been replaced with a neg ground one and not changed over.
The pulsating (if you mean the lights go brighter then dimmer while you are driving) then it sounds like you have a problem with the regulator.

[CaveatLector]

Extremely helpful, thank you. There is, in fact, an alternator. Did it originally utilize a dynamo?

Thanks for the tip on the pylsating lights, and yes they go brighter then dimmer.

[types26/36]

I'm sure a a 69 plus2 still had a generator as standard, my 72 Sprint had a generator before I converted it.
Do you have the Lucas alternator or an other make?

[Jason1]

Hi just thought I would confuse the matter I have a 1968 +2 which says Pos earth on the rev counter but is negative earth; I assume it was changed in the past. But I am still running a dynamo

I have thought about changing to an alternator but I like that it looks original 'ish'.

I would not automatically suspect low charging. As I also have problems with my headlights which may give you somewhere else to look for the fault??

My headlights pop up (none failsafe type) no problems, but in fourth gear foot on the throttle they go off. I have not looked at them yet as most of my driving is done in daylight, but I will start by checking the vacuum system has no leaks. My engine idles fast anyway which could be caused by the vacuum leak and I understand that the headlight pods have a micro switch which turns on the lights when the pods are fully up.

My thinking is if the vacuum is leaking then the pods will slowly drop tripping the micro switches and turning the lights off???

If when the lights are off and I am in fourth gear I take my foot off the throttle (closed the throttle) the lights come back on. I figure there could be only one reason for this;

1. When I close the throttle the engine draws air from the headlight vacuum as the throttles are closed blocking off this air supply, this increases the vacuum and pops the lights up fully. Lights come on??

If it was that the dynamo was not running fast enough i.e. the revs were too low, when I took my foot off the throttle the revs would decrease so the lights would not come on??

Any thoughts????

Jason