Is this a failed alternator?

Afternoon Gents

Having to recharge my battery every few days since putting my 1989 19J 90 2.5TD back on the road this week. Been SORN for a couple months whilst doing other things. When a fully charged battery is on the battery warning was flickering. Whilst driving along the volt meter will be around just under the half mark with no electrics on. However will drop if anything is switched on - significantly. The thing which is confusing me is that occasionally a few miles down the road the volt meter will shoot up to 3/4's for a while. Only when I stop and restart the engine does it then go back to under half. Its like the alternator just works now and then, seems to be less now than when I first noticed. Do I need a new alternator? Could it be a dodgy connection somewhere? I have cleaned up the battery terminals, the alternator connections?

Thanks

get a proper multi meter on it so you no what volts alternater is throwing out

if you can try dif battery first

belt slipping??

Check earth as well, and yes, a decent meter will be money well spent

Hi Guys, will get a volt meter. What and how should I test with one. Im fine with engine and trans but electrics are def not my thing. Step by step would be great help!! Belts not slipping, just checked. Tried my spare battery - same. I cleaned some of the electric connections this aft - now I have no battery light on running but Volts are still down and is not recharging - must have upset something cleaning the connections.

Thanks

follow the alternator test procedure in the FAQ section?

or take it to halfrauds.

Mine was doing this until this morning and I was convinced the belt was not slipping, It was though but only randomly. or else it was just about turning the alternator. Not enough to really charge it. Tightened the belt this morning and Hey Presto. All is perfect again. Godd strong charge and good p[owere levels even with all the electrics turned on. I had even bought new batteries. Ho hum

You are looking at voltmeter , it will have a line that is difference between "on charge" and "off charge" Before you start that is resting battery voltage , then you start up , it will then go to a reading above the "charge" line if it does not then alt is not charging , various possible reasons eg belt slip , diode , reg u/s etc . If whilst running the needle drops below "charge line" means you are taking more out of electric sytem than the alt is putting in , eg when winching , row of 10 spotlights on roof bar on etc . , you can run at a deficit for a short while , and alt will catch up when you remove elec load , or you get a bigger alt , or stop belt slipping etc . HTSH

gonzolandy said:

Mine was doing this until this morning and I was convinced the belt was not slipping, It was though but only randomly. or else it was just about turning the alternator. Not enough to really charge it. Tightened the belt this morning and Hey Presto. All is perfect again. Godd strong charge and good p[owere levels even with all the electrics turned on. I had even bought new batteries. Ho hum

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The belt is turning the alternator wheel at all revs and constant, plus the tension is fine. I would say its electrical.

Where is the earth? I would of thought if it was earth related then i wouldnt get any power from the battery? I understand basic electircs but could someone run me through problems with earths and "recharge" or alternator problems?

The Mad Hat Man said:

follow the alternator test procedure in the FAQ section?

or take it to halfrauds.

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Sorry cant locate this have you got a link?

sharpe said:

Sorry cant locate this have you got a link?

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Apologies, believe I found the document - im assuming its the pdf. As i stated before, I would be really grateful for a step by step guide (for dummys). This PDF might as well be in Spanish for me. Thanks anyway!!

The Mad Hat Man said:

Halfords Chorley (580) Store

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Hi MHM, my Halfords is next to my work office, but i would never dream of going there? The last time i went in they didnt know what a UJ steering joint was so.....im not sure why you suggest this?

I can take it the the local auto electrical garage 5 mins away, but i prefer to have a understanding to some degree of any problem before i ask to get a quote for obvious reasons. So if anyone can help further much appreciated.

Regards

Halfrauds have the kit to test the battery and the alternator - its a bit of Bosch kit which can give a printout of findings..... insist on it.