Engine/alternator electrics

Colin K

Colin K

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Hello,
My old Watermota Sea Panther blew up and I have been lucky to find another and the new one is 12v not 24 hoorah. Whoever ripped it out of the old boat just cut the wiring looms but I have worked them all out ! All apart from the alternator run. Thought I had it licked then tonight I found a relay aaah.
Ok so my quandary is that from the alternator there is a single "added"red which I think goes to the tacho? The thin yellow think goes to the charge light? But there are two meaty wires that come from the + terminal that are spiro rapped together and end with eye terminals ( the relay has these) then finally there are two spare leads again meaty that end in big eye terminals! Looking at my wiring diagram I think one/all go to the starter solenoid or battery aaah but I'm stuck.
The relay (think its a relay) is a Lucas numbers on it 33ra 12v and 334198 0298. Terminals are G meaty eye, 30 meaty eye. 85 spade 86 spade.
Any electrical charging/starter techies out there ? Cheers. Col.
 
Hi

To come up with a circuit diagram we need to know the altenator type. I suspect it might be an old Lucas 12AC with an external regulator system ( difficult for spares and un reliable) in which case you may not have all of the old installation parts.

It might be easier to start with a modern altenator as the wiring is simple.

Good luck
 
Hi Thanks for the reply, luckily ?? The alternator is brand new and its a Lucas 110179 think thats a Lucas LRA 101 if that helps. Cheers. Colin.
 
Hi

I think the LRA 101 is only 35 amp and it does have an internal regulator / control

There will be a thick wire (or two wires paired up if the installer did not have any heavy duty cable) connected to a terminal (usually) marked B+. This conects to the battery positive, (best to fit a battery switch and fuse in here)

There will be a thin wire which connects from a terminal (usually) marked D+ which connects to the charge light. The other side of the charge light need to go to neg (earth)

There will be an earth connection (thickish wire) from the frame of the alternator to the battery negative.

There may be a connection marked W with a thin wire that goes to the tacho.

If you have a two battery system with a split charge the B+ wire goes to the split charge relay / diode first.

Good luck
 
He he now that sounds a nice bit of kit. Yep its a LRA 101 36 amp.... Which is a baby? The patched in red definitely goes to the tacho and the yellow from terminal marked "ind" goes to the charge light. The two meaty 10mm ish browns are the same length and could go to one terminal on the relay and the two meaty again 10mm fly leads are different lengths and could go to different battery banks?
Cheers. Col.
 
Colin K said:
He he now that sounds a nice bit of kit. Yep its a LRA 101 36 amp.... Which is a baby? The patched in red definitely goes to the tacho and the yellow from terminal marked "ind" goes to the charge light. The two meaty 10mm ish browns are the same length and could go to one terminal on the relay and the two meaty again 10mm fly leads are different lengths and could go to different battery banks?
Cheers. Col.
Click to expand...
Split charge relay ??

From TB training :

SPCRL.gif
 
I was also thinking split charge relay.

I would guess that the spade terminals (85 and 86) are for the energising circuit (see VicS diagram above) and the 'meaty' rings (30 and G?) are for the charging current (big red line above the relay in the picture above).

If that's the case I would suggest losing it and replacing it with a modern VCR (voltage controlled relay) for split charging the domestic battery.
 
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