Fitting a replacement alternator

[pwebb]

My son has an '89 2.7 and broke down the night before last. RAC thought it was the alternator so we've got a second hand replacement coming from PorscheApart today, hopefully.
Is it straightforward for a pair of incompetant idiots to fit?
Any hints/tips/take it to a garage welcome.
Thanks
Peter

 

[Riverside]

On a lux without aircon the alternator isn't all that hard to get to, just remove the air filter box (rear bolts can be hard to reach & require patience) & it's right there.

You'll need to get underneath to undo the adjuster bar too though so best to plan ahead, jack it up first & remove the undertray etc.

Do you know what the symptoms were?

 

[pwebb]

Thanks. From what was described it conked out a couple of times, starter motor only just got it going again, electrics were dying, so did sound like a battery. That's taken a charge OK with overnight so the alternator seems logical?

Peter

 

[Riverside]

I think it's a reasonable assumption from what you describe. The Alternator itself may be okay & possibly just the voltage regulator (on the back of the alternator) is iffy. If the volt meter in the dash tends to vary depending on load (eg goes down from 13v to 12v when you switch the headlights on with the engine running) that might suggest the alternator itself is okay & just the regulator needs changing, I've never had a faulty alternator but I'd guess it would just give a permanently poor reading on the volt meter.

The volt meter should ideally read 13.8v all the time (with the engine running) and around 12v with the igintion on but engine off.

hth

 

[Jonny B]

ah right so mine reading at twelve when running and is affected/ goes to less by lights etc is down to the regulator rather than alternator? can i service the alternator at all, brushes etc Also i dont think mine has an under tray .. . '88 44s, cheers for any info
JB

 

[George Elliott]

Peter, I'd say if you can do an oil/filter change you will manage.
I would strongly agree with putting the front on stands as you will be working at a better height, and have proper access to the unit. (I always give it a push to make certain its steady after fitting the stands / before fully removing the trolley jack.)
I did my turbo alternator recently and although a bit awkward, its not that bad. (Its only two bolts at the end of the day)
I replaced the battery at the same time because I was suspicious the volts regulator/alternator fault I had damaged it? Anyway its much better now.
Good luck
George

944T

 

[sawood12]

A classic sign of a voltage regulator on it's way out is that it suddenly starts to generate a very large voltage. Your in-dash volt meter will go off the scale, any lights will go extra bright and your fan (which is always on even when your switch is off) will go haywire. For me it was intermittent and if you leave it too long to get it sorted you'll knacker your battery. Unfortunately i've found the in-dash volt gauge to be very inaccurate. Mine reads about 12.5v with all the electrics off and just under 12v with lights and fan on. When I get a voltmeter across the battery terminals I get 14v and 12.5v with the electrics on.

 

[pwebb]

Thanks all. Chickened out in the end and Keith at Addspeed kindly swapped it over on Saturday morning. Back up and running and will take her for a decent run this evening to check the voltage etc as described above.
Peter