Charge Light Glowing but Alternator OK

[Brrok_lands]

Went out in the Samurai yesterday for the first time in a while. Lousy weather here so I had the heater fan on full blast, wipers on as well as the headlights. Noticed that the charge light was glowing slightly, more so with more electrical load. Not bright but definitely on.

Got the volt meter out and I'm getting 12.4v on the battery (engine off), 14.2v engine running, 13.6v with everything electrical on.

This suggests to me that the alternator is OK but somewhere I have got a voltage drop (due to increased resistance on one side of the circuit). If I was to guess I'd start with the contacts in the ignition switch but it could be anywhere in the wiring.

Not really an issue as it looks like the battery is charging OK and its not the weather to go hunting round the wiring loom to find the problem unless I've got it wrong and this is the start of something more serious.

[ScottieJ]

I've had this for a while, well I actually forgot about it... it did it last winter or was it the winter before that??? I noticed it again briefly the other night when the weather was really bad. I probably should try and find the cause, might just be an unhealthy earth somewhere.

It only happens when there's a lot of current draw as you say, headlights, heater on full whack, wipers and stereo on.

However I have a Voltmeter in mine and as soon as I turn the heater off its back to normal so I'm thinking it might have something to do with that. Will have to get the multimeter out and do a few checks.

[Tramp]

Mine did this - just whenever things were switched on, the more things on, the more it glowed, I just assumed it was just that the tiny alternator was struggling to supply all the power I needed, off the top of my head the alternators are only 30a? units so quite small, it didn't stop my battery charging,

[ScottieJ]

I think mines a 45A alt

I do also run halogen headlight bulbs so thats more current draw than the original headlight loom is designed to handle so I would imagine in getting extra voltage drop there. One day I might get around to upgrading the headlight loom.

[Brrok_lands]

Thanks Chaps very reassuring to know its sort of normal. I'll leave it alone for now. If I get bored I might get the wiring diagrams out and work out where the problem might be should decide to go and look for it sometime when the warm sunny days return.

[ScottieJ]

Well I'm not sure if it's supposed to be normal but I wouldn't worry about it too much. We are talking about 20+ year old wiring looms so there's going to be deteriorated sections that probably could do with being replaced. Just happens so rarely on mine I always forget to actually look into it properly

[courior]

My old Skoda did this... Its the wire going from the b+ to the battery.. Basically after a while it gets corroded and puts up resistance to the flow. Use a volt meter and test the voltage from b+ to battery + ... Should be 0v. If its more than 0.2v that means that there is enough resistance in the wire to force some current through the multimeter. Just add a secondary fat cable from alternator to the battery and issue will be solved

[ScottieJ]

Worth checking but adding a secondary wire would bypass the fusible link and could cause a major headache if there was a short elsewhere in the wiring loom etc.. so it would have to be wired up through the fusible link to be safe.

If the main positive feed has corroded or broken down anywhere else then this wouldn't make a difference anyway, it isn't just a wire from the alt to the battery, the loom Ts off to the fuse box, ignition switch and stalks as well between the alt and battery.

[courior]

Fair play.. i havent dabbled in the factory wiring, just added my own for my gadgets.. The skoda had just one cable from the alt to the batt and then another from the batt to the fuse box etc.