I'm testing the voltage at the battery. I haven't had the battery tested, but I did replace it not that long ago. When I first started having problems with it not starting I thought it was just a bad battery so I had it replaced with a brand new one. I have cleaned the battery terminals.

I don't know for sure if my alarm system is aftermarket. Is there a way to check to see if I have the factory system?

Regarding the alternator, my rebuilt is a 90 amp. Do you guys recommend I get a higher amp one? If so, where do you think I should get one? I've seen the one at 928motorsports, but I want to consider all options.

 

If you bought a group 41 battery you should be OK. Around 650 cranking amps is appropriate.

 

does anyone know what a 928 draws amp wise sitting in the garage, parked for the night?

 

I believe it's 60ma. Casey, you can hook an ammeter between the neg. post and the body, and pull the ground wire. Lay the ammeter in the back so that you can see it with the hatch closed and everything off. If you're drawing more than 60ma then start pulling the fuses one by one and see if one of them results in a drop in the draw.

 

Annual maintenance:
1) Open the hatch and remove the tool panel. Remove the carpet and spare tire cover. Remove the spare, tools, etc. Open the battery box.
2) Disconnect the ground cable from the chassis. Remove the negative battery terminal. Remove the positive battery terminal. Remove the battery. Use extreme caution to avoid getting battery acid or residue from the top of the battery or cables in your eyes. Goggles are recommended. If the battery brushes against your clothes, you can end up with holes.
3) Clean the battery terminals until they are bright and shiny. Dull gray won't do. If it is possible to check the fluid level in the battery, do so. Fill to the rings. Wash the battery. Put it on a charger if possible.
4) Clean the battery box, removing all corrosion. Wash the battery box. After it dries, touch up the finish as required.
5) Clean the battery cable terminals (all three) until the connection area is clean and shiny. Dull gray won't do. Clean the connection area on the chassis.
6) Clean the speedometer/odometer drive electrical connector in the right forward corner of the spare tire well (pre-'90 models).
7) Raise the hood (bonnet). Remove the protective cap from the jump start terminal and pull the protective plastic cover from the terminal. If you are missing the cover or the cap, replace them - they are critical items. If there is no cover, water will enter the connector and corrode the connectors and wires, causing serious electrical problems.
8) If the connections are clean and tight, replace the cover and cap. If the connections show any corrosion or looseness, disassemble, clean and reassemble.
9) Jack the right front of the car so that you can SAFELY work underneath.
10) Remove the ground cable that runs from the right side of the engine to the chassis. Clean both ends of the cable, and check for corrosion in the cable. Clean the connection points, and replace the cable.
11) Check the heavy cable connection on the starter solenoid for looseness or corrosion.
12) Check the moderately heavy wires on the same connection for corrosion and breaks inside the insulation. These carry the charging current from the alternator.
13) Check the small yellow wire connection for corrosion and tightness. This wire triggers the starter solenoid.
14) Lower the car. Fold back the carpet and open the central power panel cover.
15) Check the main power connections at the top of the panel for tightness and corrosion. Check the ground connections above the panel for tightness and corrosion.
16) Disconnect and reinstall each plug at the bottom of the panel. If there is any trace of corrosion, clean the connections carefully.
17) If you are having electrical problems, remove each fuse and reinsert three times. Check the fuses for the proper value, and examine them visually for damage or corrosion. Test them if desired. Later cars have a fuse tester built into one of the relays.
18) If you feel that it is necessary, remove and reinsert each relay. This won't be easy, as they fit very tightly in some cases. Porsche sells a relay removal tool, but I am not impressed. It is basically a pair of pliers with square jaws, and will pull the relay apart. One tool that works well is a spark plug boot removal tool. It is a thin but strong sheet metal tool shaped like a "J" with the top 1/8" bent over at a right angle. You can put this angle under the bottom edge of the relay and lift it out - IF the battery is disconnected!
19) Close the panel and replace the carpet.
20) Replace the battery. Install the positive cable. Install the negative cable. Put a drop of oil on each nut. Connect the chassis end of the ground (negative) cable. Lubricate the battery box latch and close the box.
21) Lubricate the wiper drive shaft and hatch latch mechanism.
22) Clean the spare tire, jack and tools. Put a couple of large heavy plastic garbage bags in the spare tire well for emergencies, along with a tube of hand cleaner and some paper towels. Install the cover and carpet.
23) Lubricate the jack, and put it inside the tool panel. Clean and lubricate the tools. Reinstall the tool and tool panel.
24) Reset the clock and radio presets.
25) Reach up under the dash and make sure that the ignition switch is firmly plugged in.

A couple of hours of quality time with your 928 once a year can forestall many problems.

 

In addition to performing the maintenance Wally recommends, I still want to get a new alternator just to make sure that is no longer a problem. I'm planning on getting a new 90 amp, but would it be wise to consider a higher amp one?

Also, I still really want to disconnect the alarm system, since I know for a fact that there is something wrong with that. As I've said, I'm not really sure if its factory or not, but is there a definitive way to find out?

Thanks

 

Well, I talked to my friend today that installed the alternator. I asked him if he noticed if the cooling shroud was on the alternator and he said that he didn't think so. Could not having the cooling shroud be causing my alternators to overheat and thus become ruined?

Does anybody have a picture they can post of the cooling shroud installed on the alternator? I'd imagine it'd be pretty obvious if it was on there, right?

Thanks

 

<http://members.rennlist.com/v1uhoh/alternat.htm>

 

Maybe do the 105 Amp Delco conversion. Cheap and pretty easy. Local parts, even in MT.

 

Well, I already ordered the stock 90 amp from 928 International a few days ago. Just last night I did some more reading on the alternator and the cooling shroud and I didn't get a chance to ask my friend about it until today.

So, is this what I need?

and the hose?

I'm not sure what all I need to get.

 

Are you sure your battery isn't just past its life?

 

I ask, because even a new battery, once drained of all power a few times, will do as you describe...

 

Well, I'm not sure the battery isn't a goner...but I'm not sure if the battery was really drained of all power. I suppose its always a possibility though. What do guys think of the no cooling shroud being the problem? Is it unlikely? What is the proper way to route the hose?

I'm still clueless as to how to disable the alarm system...I know there's a glitch of some sort with that thing.

 

you need the shroud, it protects against dust and water too, since the alt is 3 inches off the ground. Route the hose up against the plastic vertical piece that acts as a front mud guard, it bends in a U up there and turns down vertically to end in a short open hose. Toward the top is the air temp sensor (not sure this exists in an older car)

 

Batteries will do odd things. The GTS was dead, no lights on dash, nothing. It had been sitting for weeks with batt disconnected, showed 12.8V. As I checked various electrics, another week passed, still disconnected. Voltage now showed less than 12.0, so I take it out, it is 2.5 years old Duralast, not sealed, all cells were dry; replenished H20. Charged for 8 hours, voltage held overnight at 13.4. It would only cause starter solenoid to whrrrrr. Replaced it, no problem. Someone else said, "Aren't all batts now sealed?" I know they aren't but I did assume that the previous maint had been excellent and this would have a sealed unit. Don't assume.

[edit] In this situation I would add that I think a batt load tester (or as Bill B says a hygrometer) is a step up over a DVM. I just happened to catch it as it was going over the abyss and the volts showed good, but I assume the amps were gone and I wasted another day messing with it when a more complete test would have save me the time and trouble.