Popup charging woes...

[SamK]

Popup was due a run out last weekend but the voltage was only showing 10v.
Started with my booster pack attached but once disconnected the voltage still showed 10v.
Tickover was fine and when revved the voltage dropped further and returned to 10v on tickover.

What would be the main culprit?

Sam.

[johnr]

well, the three main suspects are , duff battery, duff generator or duff reg rec. the complicating factor is that any one of them can, in time, take out either or both of the other two. it might well be worth checking the earths, particularly the earth for the reg rec, make sure its earthed directly back to the battery neg if poss, but from what you say, its sounding to me like your alternator is goosed. but only a session with the multimeter will show whather thats correct.

[fossie]

Only showing 10v , then you must start with the battery ....even a goosed 12v should show minimum 11.5v

[SamK]

Looks like it'll be the weekend before I'll have a chance to check it out.
I'll start with the battery and take it from there...

[fossie]

As said no matter what battery is goosed, however why? While battery off check the earth connections , make sure the reg rec earth goes direct to battery not the original bottom of battery box.

Also alternator wires from alternator direct to reg rec.."......the main issue with the original wiring layout. Relies on all 3 phases working. But if you are running with lights off the last phase is not operating. Leading to burn out..

Worst case would mean , new reg , can be sourced for £35 , alternator £45 ish and a gasket £10

Battery a given but 14LA2 £25.

[SamK]

But if you are running with lights off the last phase is not operating. Leading to burn out..

Interesting Fossie,
I fitted some LED running lights, so the last couple of runs had no headlight on.

[SamK]

Took the battery off and one of the cells looked damaged inside.
So only running on 5 cells would give 10V instead of 12.

Fitted other battery and started up no problem... nice easy fix

[katmarch]

Yes but why did it kill the cell? With multimeter attached from tick over to about 4k you should get from 13.5 to 14.5 V charge. If as the rpm increases the voltage continues to go up much above 14.5 the regulator part of the regrec is not preventing over charge.

Basically the rectifier bit turns the 3 alternating current yellow wires into direct current by 6 one way valves ( dieodes) the regulator bit clamps the excess voltage down to ground as the RPM goes up.

Give me a call if you want, numbers in pride. I've been doing electrics for years.

Steve

[SamK]

Cheers Steve,
I'll have another look at the weekend.