General Battery light ON.............ignition OFF

[murfman53]

Hi to all,

Details of vehicle.

Fiat Ducato 2.5 non turbo 1992 Weinsberg camper.

Details of the problem, and actions taken.

After doing the regular DOE (MOT), failed a small hole on the cill under drivers

door.

Fabricated a portion of the cill, and ready to migweld into place.

Disconnected battery, and disconnected all cables from alternator.

Welded part into place, then dressed welds and completed with primer

and paint.

Connected up alternator, then connected the battery.

Then wanted to start up camper, but noticed the battery (charging light)

ON!!! The ignition was OFF.

Suspected the alternator diodes, but the alternator was disconnected

before I proceeded with the welding. Decided to get alternator checked

anyway. Brought it to a alternator specialist in town.He checked and found

it was working 100%

I asked for his opinion on what the problem might be, and his belief was

that the fault lay elsewhere but nothing wrong with the alternator.

Refitted alternator, and connected leads, and connected up the battery.

Ignition is OFF................battery light still on. I then disconnected thin

wire from the alternator, the battery light went out. Reconnected it and

the light came back on again.

Am I correct in saying that I have 12 volts on the cable before connecting

to the alternator. Is this correct I wonder. Should the 12 volts come from

the alternator to the battery lamp, and the otherside of the lamp down to

earth. Or should the cable be live, and then receive its earth from the

alternator to complete the circuit. I'm not sure to be honest.

I have no wiring diagrams to go by, but the circuit should be much like

any other I suppose.

Any suggestions or help would be greatly appreciated.

Thanks a million.

John.

 

[jackwhoo]

The thin wire to the alternator should be + battery voltage with the key turned on . Zero volts with key off.

 

[murfman53]

Hi jackwhoo,

Thanks for your reply. I was thinking along your lines, but needed confirmation.

If I'm correct, with ignition on, the battery voltage supplies the field windings with

this voltage, and kick starts the charging process when the engine revolves.

Excites it, I believe they call it.

I have somehow supplied voltage to this wire, even though the ignition is OFF.

Might have an issue with the ignition switch itself. Or, I may trace back this wire

and see exactly along its path that it is not touching any live wire that it shouldn't

be.

Would it be correct to say, that during the charging process, the lamp is supplied

with voltage on both legs, ( no ground ) which in turn cancels the light to OFF.

Its a peculiar problem I haven't seen before.

Thanks a million jackwhoo for the insight. It gives me a path to look at.

Cheers.

John.

 

[jontee61]

hi murfman. when you disconnected the battery before welding did you disconnect both earth and live or just live from the battery, as it would seem that alternator may be at fault even though its been checked. just a thought good luck.

 

[murfman53]

Hi jontee61,

I played on the side of caution, and disconnected both positive and earth leads

on the battery. Still thinking I may have damaged the alternator, I got it checked

to be on the safe side..................but it seems to be working perfectly accordingly

to the specialist. I have no doubt to his conclusion, so I must see if the problem lies

elsewhere, as he suggested................for the time being.

Thanks for your input all the same. When ever I have a job to do where you need to

disconnect the battery, out of second nature, I always remove both leads.

Thanks a mill.

John.

 

[murfman53]

Hi to all,

Found the problem......................It was me!!!

Just to recap. When i was ready to do the welding, I disconnected the leads

from the alternator, and battery cables.

When I finished the welding was ready to reconnect all the leads and cables.

This is where I made my mistake.I connected the small wire to the alternator.

However I wasn't aware that there was two spade lug connections on the alternator.

My mistake was I connected to the wrong spade lug connection marked +

When I should have connected the wire to the spade lug marked D+

When your under the camper on jacks with a torch for light to see what your doing,

vision is limited. We've all been there at some time or another. This was my time.

A simple mistake, but thankfully a simple solution. Everything is as it should be now.

Again thanks for the contributions from fellow members. Always appreciated.

Happy camper.

John.