924Board.org

percy · Joined: 12 Feb 2004 Posts: 11 Location: London, UK

Hello,
I have owned a 924 Auto for about 7 years now, but I've only just discovered this board. I was interested to read other threads about the problems of water leaking in etc. I cured my battery shelf leak with about 7 layers of fibreglass matting and resin, but now its the sunroof (lift-off type) thats letting in water. Boy, does the cabin stink with the carpets and seat foam wringing wet!

However, something else is bugging me. The red low-charge warning light is on, but dims when the engine is revved. I need to eliminate alternator belt tension first. I've loosened off the hinge bolt, but cannot find a way of moving the alternator to increase tension of the belt.

Any ideas??

Lizard · Posted: Sat Feb 14, 2004 2:45 am Post subject:

as per the moonroof, make sure the holes (1 in each corner) are not blocked, test by pouring hot water down the holes, and might be a good time to replace the moonroof seal at this time too.

as per the alt light, there is a small bolt (8mm bolt) on the alt replace the connector on here, and then trace this wire back to the firewall and you will find a 3 pin connector on the firewall pull this apart and clean these terminals or replace them, while in the engine bay run a good ground (min 4 guage) from the alt housing to the body or the gound point for the battery. next we move onto inside the car, pop out the guage which has that light, clean all the connectors on it, including the connectors for the light, then move under the dash and up behind the fuse box and yu will find 2 crown ground points, remove these and either clean them and replace ALL the connectors, or put in a distrobution block and replace all the connectors as well problem should be gone at this time,
also of course verify the voltage output of the alt
_________________
3 928s,

Lizard · Posted: Sat Feb 14, 2004 2:45 am Post subject:

oh and welcome sorry forgot about that
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3 928s,

percy · Joined: 12 Feb 2004 Posts: 11 Location: London, UK

Many thanks for that reply Lizard.
I'll certainly follow up those ideas and hopefully get the thing fixed.
Thanks again.

924RACR · Posted: Sat Feb 14, 2004 3:50 am Post subject:

Wilkommen!

To adjust the alt belt tension, you need to loosen the bolt/nut on the bottom, where the tension adjustment is - I gather you haven't touched that yet? You may need to remove the undertray, if it's still present, to see this more clearly (though it can be adjusted from above, in you know what you're doing).

Complicating the attempts to set the tension can be the rubber mounting bushings for the alternator (on the pivot bolt), which soften and distort. They frustrate any attempt to apply tension, as they allow the alternator to twist and release some of the tension. It's very easy to establish if these are bad; visual inspection from above will reveal if the alternator pulley is not parallel to the other pullies, but at an angle; if this is the case, plan on replacing those bushings (not that expensive from the dealer) next you replace the belt.

But Lizard's quite right about checking the connector and other wiring concerns. There's also a ground strap he doesn't mention, grounding the alternator (from a bolt on the rear cover) to the block, which needs to be in good shape to get a good charge.

One final thing, if none of the above resolve the issue, would be to replace the voltage regulator and brushes - one part to replace both, and really can make a huge difference in charging performance if worn out. But that requires actually spending a few bucks, so check the cheap and easy stuff first!

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Lizard · Posted: Sat Feb 14, 2004 3:50 am Post subject:

while you are there you may as well run at least a 4 guage wire from the alt DIRECTLY to the battery, not going to the starter then to the battery also replace the wire running from the battery to the starter, and put a good heat shielding on it or it will melt, then also run a good ground wire from the negative of the battery (or the battery grounding point) to one of the starter bolts,

now 4 guage wire would work for this but I would recommend a 2 guage myself, although I personaly have a 0 guage running to my starter and my engine cranks right over
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3 928s,