Fried Battery

[Darthmjh]

Over the last few times I have used the car my Becker radio has intermittently been turning off and back on again. At idle it was on and then at slow speeds on and off. When I was on the motorway it always turned off.

I thought it was a loose connection. So yesterday I took it out and removed the connections and refitted.

I went on a long motorway journey today and the same thing was happening. On the way home there was a strange smell in the car.

Once I got home I lifted the front bonnet, the smell hit me. There was condensation and the battery was making a fizzing noise. It then started smoking.

I removed the battery and replaced with a spare. I tested with a meter and The alternator was pushing out 19v!

I assume this is why the radio was playing up.

Could this be the voltage regulator in the alternator? Is it an easy job to replace ?

 

[mikelb04]

Almost certainly your regulator
2 screws at the back of the alternator, if it's OE Bosch take the number and give somebody like Wood Auto Supplies in Huddersfield a ring and they can supply a replacement at a sensible price
looks like they are out of stock of Bosch ones but most Auto Electricians would use a pattern part one so you should be fine Get a voltmeter and test for 14.5v at the battery when you have changed it
Only other problem is how old is the Alternator if the regulator has failed and its an original one things like bearings must be quite old as well it might be worth thinking about getting it re-built when you have time

 

[Darthmjh]

Thanks for that. I have no idea how old the alternator is.

I am using a CTEK trickle charger in the garage whilst the battery is plugged into the car. Could this have caused the regulator to pop. I don't know if the battery should have been disconnected.

 

[mikelb04]

pretty unlikely
CTEK are designed to be used with the battery still connected even my newest Porsche with all its fancy electronics lives connected to a CTEK permanently without a problem
Chances are 60-70% of the people on this forum use them like that on their car so just put it down to old bits failing at some point

 

[TobesEtc]

For a split second I thought this post was about some Scottish delicacy!

 

[Darthmjh]

After a few delivery issues of a new voltage regulator, it arrived on Friday. I tried to fit it this weekend.

I followed the instructions here: https://www.porscheclubgb.com/forum/tm.aspx?m=1075161

and got to the part of fitting the new voltage regulator, which said:

"Due to the new brushes, it will take a small amount of jigging around to get it in but it's not hard. "

Well, myself and 2 others attempted it and could not manage it.

Plan B. Remove the alternator. I couldn't remove the small rear impellor so struggled to get wires unbolted. However nearly 2 hours later the alternator was out.

Whilst it's out I am going to strip it and check it over.

 

[AndyS]

I followed the instructions here: https://www.porscheclubgb.com/forum/tm.aspx?m=1075161

and got to the part of fitting the new voltage regulator, which said:

"Due to the new brushes, it will take a small amount of jigging around to get it in but it's not hard. "

Well, myself and 2 others attempted it and could not manage it.

Plan B. Remove the alternator. I couldn't remove the small rear impellor so struggled to get wires unbolted. However nearly 2 hours later the alternator was out.

This sounds like the kind of experience I have whenever I try a simple job.
Nowadays I just end up dropping the car off with someone else :nooo:

 

[Darthmjh]

I have managed to take the large fan off the alternator. But still cannot get the small black plastic fan off the rear, its stuck solid.

I can't apply heat as this will melt then fan.

I may just leave it on and let someone else worry about it. I am going to be giving the alternator to a company that can check it over for me. The commutator is warn with a groove from where the brushes touch it from the voltage regulator.

 

[Tycho]

When I was replacing my alternator a few years ago the rear small black fan caused problems. I was having trouble identifying the part number to order a replacement. The OPC parts manager realised that only half the fan was present. In the past someone must have tried to take it off, split it in two & decided to leave it as it was. As I recall my mechanic mate managed to remove without too many problems. I can see if he remembers how if necessary.

 

[Darthmjh]

Thanks for the offer, but I went back to it today and tried again. I managed to move the fan enough to get a screwdriver behind it and slowly levered it up and took it off.

As I have the fan and alternator out I am thinking of painting the fan housing. Not sure if to power coat it or paint it. From what I have read I think it was anodised originally.

Any recommendations?

 

[Tycho]

After reading all the pros and cons I went for painting, satin black for the housing and iris blue for the fan.

 

[Darthmjh]

After reading all the pros and cons I went for painting, satin black for the housing and iris blue for the fan.

Thanks for the advice. What paint did you use ?

Cheers

 

[Tycho]

Just checked and I had it done nearly six years ago. When I went to chat with a recommended local bodyshop I found that the owner had a 996 and was working on a 993 at the time. I was satisfied that he knew his stuff – was aware that the fan was magnesium & the preparation needed. I wanted the fan done body colour & he suggested satin black for the shroud. After that I left the rest to him so not sure what he used. No problems since (touch wood!).

 

[Darthmjh]

Just checked and I had it done nearly six years ago. When I went to chat with a recommended local bodyshop I found that the owner had a 996 and was working on a 993 at the time. I was satisfied that he knew his stuff – was aware that the fan was magnesium & the preparation needed. I wanted the fan done body colour & he suggested satin black for the shroud. After that I left the rest to him so not sure what he used. No problems since (touch wood!).

Thanks for the info. I didn't realise it was magnesium. I think I will first clean it to see how it comes out.

 

[A993LAD]

Definitely worth painting whilst it's off the car in my view. The unpainted magnesium housing always seems to get white powdery corrosion over time.

Good thread here for seeing colour options and paint finishes....

http://911uk.com/viewtopic.php?t=109615&postdays=0&postorder=asc&start=0

I went for matt black on both.

Still looks good after 5 years.

Before and after shots here...........