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Charging system woes
https://forums.tipec.net/viewtopic.php?f=25&t=20187		 Page 1 of 1
Author:  piemuncher [ Sun Jul 26, 2015 2:16 pm ]
Post subject:  Charging system woes
Hi all,

My car is not charging... Running at between 8-11 volts regardless of run times or toys switched on.

I have so far:

Replaced voltage regulator
Removed and spun the alternator (seems fine, slip rings seem ok)
Cleaned points on back of alternator
Tensioned belt
Stuck a voltmeter on it, 12.5 turned off, 11.5 idling!

Where is the next place to look, starter motor? It's making me frustrated as it's the only mechanical issue with the car!

Once this is sorted, I can make it stop poisoning me with fumes and can also change the exhaust!

Will
Author:  Prophead [ Sun Jul 26, 2015 5:47 pm ]
Post subject:  Re: Charging system woes
piemuncher wrote:
Hi all,


Stuck a voltmeter on it, 12.5 turned off, 11.5 idling!


Will

Where did you stick the voltmeter? Not 100% on this but think the alternator should be outputting about 14volts to charge the battery.
Author:  white944 [ Sun Jul 26, 2015 6:38 pm ]
Post subject:  Re: Charging system woes
Just lob another alternator on it. I paid £35 for one from Douglas Valley on Ebay.
Author:  Waylander [ Sun Jul 26, 2015 8:15 pm ]
Post subject:  Re: Charging system woes
Rectifier is done
Author:  piemuncher [ Sun Jul 26, 2015 8:43 pm ]
Post subject:  Re: Charging system woes
Hi,

Voltmeter was across the battery.

To add insult to injury I now have no alternator light on the dash and consequently my last battery reading was 6.5v.

The only things I have done are remove and refit alternator and refit two large fittings to starter (I had missed one first time).

Argh! Any recommendations? Thanks waylander will look at rectifier.

Ps found a loose blue cable with spade connector. Loose behind fuse board.... Is this right?

Will
Author:  Rhett [ Sun Jul 26, 2015 9:06 pm ]
Post subject:  Re: Charging system woes
Hi, you don't say what year your 944 is. If an early car, have a look at this thread on Pelican.

http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/776325-early-944-fuse-box-wiring-charging-system-warning-light.html

It mentions the blue wire - so that is important to the charging circuit.

Also, I have a suspicion that the alt light bulb is required for the exciter circuit in the alternator to work, so if the bulb is disconnected (blue wire...) or blown, the alt will not charge. Lots of good info on Pelican regards this situation. Have a search...

If a later car I think the situation is basically the same, but different wiring diagrams, etc.

:bounce:
Author:  piemuncher [ Mon Jul 27, 2015 9:36 am ]
Post subject:  Re: Charging system woes
Thanks Rhett,

I think I've read through that one previous (plus about 30 other threads across pelican parts!).

Where does the blue wire terminate where it goes through the grommet into the cabin (fuse board?).

Also, stupid question. The large terminal on the starter - are there two connections onto this?

Will
Author:  piemuncher [ Mon Jul 27, 2015 9:39 am ]
Post subject:  Re: Charging system woes
Is this a coincidence?
Author:  Rhett [ Mon Jul 27, 2015 12:02 pm ]
Post subject:  Re: Charging system woes
piemuncher wrote:

Where does the blue wire terminate where it goes through the grommet into the cabin (fuse board?).

Also, stupid question. The large terminal on the starter - are there two connections onto this?

Will


I don't have an early car, so cannot advise on the routing of the blue wire, but ultimately it must end up at the alternator light in the instrument panel. It should not go through any relays, etc. so there should be a direct continuity from the alternator terminal to the light, and the bulb must be OK too.

There are generally always two connections on the starter (as shown in the circuit diagram), one directly from the battery, the other from the alternator. It is important that these large connections are nice and clean. Always disconnect the battery before putting a spanner anywhere near these!

The relay and blue wire situation may be a red herring in this case, unless you can determine if the blue wire you have shown in the photo is actually connected to the alternator.

Hope that helps a bit? :wink:
Author:  piemuncher [ Thu Aug 20, 2015 7:27 am ]
Post subject:  Re: Charging system woes
Hi All,

To round this thread off for any future people that stumble upon it.

My symptoms were:

1. No charging (car running at around 11.5-12v)
2. Dim lights
3. Did have the battery light

I did the following with no change:

1. New voltage regulator
2. Tensioned belt
3. Ensured blue wire etc were correctly fitted.
4. Found and connected the loose connector to the starter motor (idiot!)

It turns out the issue was with the alternator. I replaced my old one with a used working one, transfered the new voltage regulator over and it now sites nicely between 13-14v. I can now see the clocks in the dark - happy days!

Will
Author:  piemuncher [ Thu Aug 20, 2015 7:28 am ]
Post subject:  Re: Charging system woes
PS Rhett was seemingly correct, the blue wire under the dash wasn't related.

Will
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