Disco-Skipper

Active Member
Hi All,

A couple of days ago I had a charging issue with my td5 so I got it back home and checked it and noted the voltage across the battery was just north of 12V with the engine running so I assumed that the alternator had packed up.

I went to double check it again today and the battery light went out on start up and it was reading over 14V which gave me a glimmer of hope. However, 5-10 minutes into a quick test run and the light returned and the voltage had dropped back down to around 12V

I cant find anywhere which explains this sporadic charging, only permanent failure

Do we think a new alternator will solve it or are these symptoms of wiring issues instead?

Thanks for your thoughts
 
Hi All,

A couple of days ago I had a charging issue with my td5 so I got it back home and checked it and noted the voltage across the battery was just north of 12V with the engine running so I assumed that the alternator had packed up.

I went to double check it again today and the battery light went out on start up and it was reading over 14V which gave me a glimmer of hope. However, 5-10 minutes into a quick test run and the light returned and the voltage had dropped back down to around 12V

I cant find anywhere which explains this sporadic charging, only permanent failure

Do we think a new alternator will solve it or are these symptoms of wiring issues instead?

Thanks for your thoughts
The Brushes are kaput and fail to make contact when its warm? I had one that would pack up if I hit a big pothole. I found there were almost no brushes left and big trenches cut in the commutator (or whatever it is called).
 
That would make very good sense, the issue only reared its head since it been so hot out - the day it first came up it was 31 degrees! Sounds like it's time for a new one
 
Could also be a dodgy diode pack.
I once drove a minibus full of kids to Paris and around there for a week.
Similar symptoms to you. Took it to a French garage, they tested it, said it would get us home. On the motorway coming back from Portsmouth it was getting slower and slower and the lights were growing dimmer and dimmer, when suddenly with a jerk everything went back to normal.
Funny things electronix!
But in my case the ignition light glowed ever so dimly but it glowed.
 
Having a similar problem which I thought I'd fixed: https://www.landyzone.co.uk/land-ro...new-rectifier-and-regulator-sorted-it.370681/
However after replacing the voltage regulator, brushes and rectifier pack the light goes off on starting and at idle but comes on getting progressively brighter as the revs increase.
The battery voltage is approx.13.5 and up to 13.8 when running and no sign of poor charging.
It has been suggested that the exciter wiring from the ign to the dash warning lamp to the D+ post on the alt is earthing somewhere.
Will next try a wire from the battery + to the D+ post with a bulb in line to see if the light still comes on = alt faulty or not = wiring fault.
 
Hi All,

A couple of days ago I had a charging issue with my td5 so I got it back home and checked it and noted the voltage across the battery was just north of 12V with the engine running so I assumed that the alternator had packed up.

I went to double check it again today and the battery light went out on start up and it was reading over 14V which gave me a glimmer of hope. However, 5-10 minutes into a quick test run and the light returned and the voltage had dropped back down to around 12V

I cant find anywhere which explains this sporadic charging, only permanent failure

Do we think a new alternator will solve it or are these symptoms of wiring issues instead?

Thanks for your thoughts
Hi, I have a usb charger in the fag lighter socket with volt meter built in & when I start it it shows 14.4V but then goes down to 13.5V once the eng. is warm so I'll be interested if you try brush replacement or whole alternator, if you wouldn't mind keeping us updated please.
 
I'm allergic to all things electrical so am inclined to fork out for a new alternator to save me the hassle - especially since I'm not aware of the history on the car so it could well be ancient

Are the diode pack, voltage regulator, brushes and rectifier pack all internal to the alternator? I'm hoping I can replace all of the potentially faulty bits with that one lump

I'll be sure you keep you posted with what I do and how much success I get with it
 
Good news! I'll definitely go down that route then - I'm a sucker for new shiny bits too so its a win win
I know what you mean I spent hours unseizing the rear wiper motor which didn't really matter as it was off the road at the time (still working fine) but now it's on the road alternator wise I'd tempted to just replace the whole thing. So if/when you do it & it improves those charging rates, if you can post the results that'll be much appreciated. The same usb/volt meter in my FL1 reads 14.4v when running regardless of load.
 

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