Lotus Elan

Generator/Alternator cable rating

PostPost by: gav » Fri Dec 01, 2023 11:45 am

Thanks Steve - thats really helpful

So if I am running circuits that draw power from the alternator through the existing wiring loom, they will continue to run and if that exceeds the charge that the battery needs, the second cable will essentially top up the missing portion.

On this basis, the battery should never go flat even if the other circuits are taking all of their allocated power.

Does that sound right?

This doesnt deal with undersized cables, nor circuit mods over the years but would allow the stsus quo to remain in the interim.

Thanks
Gavin
One day I'll actually finish - completely - one day....
User avatar
gav
Fourth Gear
Fourth Gear
 
Posts: 526
Joined: 26 Jan 2004
Location: Hertfordshire UK

PostPost by: steve lyle » Fri Dec 01, 2023 6:38 pm

I think you’ve got it.

In my experience the original loom isn’t bad. When I rewired my car, I did find a significant benefit to upsizing the window motor wiring - doing so dramatically increased the lift/lowering speed. I also upsized the power wire to the headlights/horn and radiator fan.
Steve Lyle
1972 Elan Sprint 0248k @ https://www.mgexp.com/registry/1972-Lot ... 48K.30245/
1972 MGB Roadster @ https://www.mgexp.com/registry/1972-MG- ... 842G.4498/
2007 BMW 335i Coupe
User avatar
steve lyle
Third Gear
Third Gear
 
Posts: 462
Joined: 15 Jun 2015
Location: Tulsa, OK USA

PostPost by: gav » Sat Dec 02, 2023 8:54 am

Many thanks Steve

Lots of food for thought
One day I'll actually finish - completely - one day....
User avatar
gav
Fourth Gear
Fourth Gear
 
Posts: 526
Joined: 26 Jan 2004
Location: Hertfordshire UK

PostPost by: gav » Sun Dec 10, 2023 7:02 pm

Ive been doing some homework.......

...and discovered that my auto electrician joined 3 cables (colours yet to be confirmed but one is definitely the original brown battery link from the control box to the solenoid). One of the cables is a newer 44 strand / 0.26 mm cable which I think equates to 2.4mm sq or 14 gauge providing around 25A. This is what is connected to the alternator alongside the cable from the ignition switch which includes the ignition light. I dont seem to have any exciter cable to the alternator but it does seem to work so presumably I dont need one.
I will expose the junction where these old control box cables have been joined but my instinct is to abandon the newer 25A cable to the alternator that sprouts from that soldered joint and replace it with a much higher amperage one direct to the battery via the solenoid connection.
I plan to retain the brown cable that used to run from the solenoid to post B of the control box because I suspect that it still feeds the original circuits and with luck I will be where I need to be.
Hope this makes sense and happy to take thoughts as to the logic.
Thanks
Gavin
One day I'll actually finish - completely - one day....
User avatar
gav
Fourth Gear
Fourth Gear
 
Posts: 526
Joined: 26 Jan 2004
Location: Hertfordshire UK
Previous

Total Online:

Users browsing this forum: No registered users and 16 guests