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Charging system S4

PostPosted: Fri Jun 13, 2014 3:48 pm
by djb222
Hi

Looks like the charging on my S4 may have a fault somewhere, going to do some testing tomorrow. This got me thinking about changing to an alternator system anyway. My head is saying change, but my heart is saying renew the original system. Just wondering what the consensus is amongst you guys, sympathetically upgrade or stick with originality with all of its inherent foibles.

Regards
David

Re: Charging system S4

PostPosted: Fri Jun 13, 2014 4:09 pm
by AHM
I have one elan on a new alternator and one on an old dynamo with new control box.

No problem with the Dynamo - And I have no intention of sitting in a traffic jam on a cold wet winters night.

There is some folklore surrounding the subject - With an ammeter mounted in the dash I can see that it isn't true that a Dynamo doesn't charge at tickover, and that it is well up to the job.

Re: Charging system S4

PostPosted: Fri Jun 13, 2014 4:12 pm
by alan
you could convert to alternateur, the same as instructions in the Lotus Workshop Manuel. So official conversion :mrgreen:

Re: Charging system S4

PostPosted: Sat Jun 14, 2014 3:10 pm
by AHM
Started the S3 paying particular attention to the ammeter.

I may have been a bit bold with my statement above - doesn't charge much at tickover. Infact with the engine cold and the tickover a bit low, the regulator isn't cutting out quite early enough and it is discharging!

Give it a few more revs and I easly get more than 20 amps

Re: Charging system S4

PostPosted: Sat Jun 14, 2014 3:38 pm
by Elanintheforest
My S4 has an alternator and I have collected together the bits, including a 2nd hand loom, to convert back to dynamo.

We've gone through all the arguments many times, but unless you are adding electrical goodies to the system (and beefing up the wiring / fuses and adding relays) the dynamo does fine. I used my S3 (with dynamo) for 5 years commuting, summer and winter, in the dark and rain and cold, and it always stated the next morning with no problem.

Don't think that the alternator route is any more reliable either...I'm on my third alternator in 6 years on my E Type, and that was original equipment!

Get a new voltage regulator (the other is probably nearly 45 years old....35 years past it's expected life!) and overhaul the dynamo...there's nothing much else to go wrong. Oh, check all the earths and connectors as well....dynamo or alternator!

Mark Kempson

Re: Charging system S4

PostPosted: Sat Jun 14, 2014 5:22 pm
by djb222
Just checked the Dynamo and it's working just fine. A visual inspection of the regulator, ahead of a test, looked as Mark suggested a bit worse for wear, white deposits etc. as you can see.

Image

All in all I am going to replace the regulator, could be 45years old ( certainly looks it) and stay with the current set up.

On a slightly different subject, although I haven't driven the car very far yet, just moving 50yds from one garage to another, when I turn off the ignition there is a hissing sound coming from somewhere in the engine bay. I'm working my way through the workshop manual but haven't spotted any reference. Any ideas?

The more I look over the car the more jobs appear .

Re: Charging system S4

PostPosted: Sat Jun 14, 2014 8:57 pm
by Elanintheforest
My guess it would be a leak on a headlamp vacuum pipe or unit. Have a look at the three-way connector at the bottom of the vacuum tank...they go quite frequently.
Mark

Re: Charging system S4

PostPosted: Sun Jun 15, 2014 10:20 am
by billwill
I see you live in Birmingham.

I live in London and in the early days 1969-1982 I used my S3 daily to commute 6 to 10 miles each way in London traffic.

I don't recall quite how often, but my guess is that I had to beg push starts from passers by on at least 6 possibly 8 times due to the battery being too flat to start the car.

In my opinion a dynamo in an Elan will not keep the battery charged during winter commuting in the dark in dense city traffic with multiple stops giving an average speed of say 10 to 12 mph.

I converted to alternator in 1982 and have never needed a push start since.

Of course nowadays, you are probably not going to use an Elan as a city commuter car, so this may be an irrelevant factor.