Grey Wolf

As many of you know, Ed picked up his new 928 "the BluMaxx" on saturday in Virginia, and is driving it home to Bozeman Montana. I got a call tonight that he is having charging problems even though the previous owner just replaced the alternator. Says the reading is 14 at the alternator but not at the amp meter.
Meter has always shown 12, and the P/O said that he never had a problem with it. Tonight it went into the red zone and ed pulled off and found a room in the middle of nowhere. He is about a half hours drive from Sioux Falls, SD. and wants to know if anyone knows of a good machanic there.
He found two places in the ph book. Graham Automotive, and Classic Import Repairs and would like some sort of feedback if possible.
One thing Ed notice when staring the car is a buzzing noise that last for a few seconds and goes away, in or around the area of the CE panel. One other symptom is the background pod lights stay on even when the headlights ect, are off.
Ed will get on rennlist tomorrow if and when he gets to Sioux Falls so any mechanic info, or problem solving would be greatly appreciated.

Thanks...........

Mrmerlin

buzzing could be a relay thats not getting enough signal or an interruped signal.
I would check the battery connections and the belt tension, also see if the cooler hose is on the rear cover, its possible that an errant stone could have gotten sucked into the alternator with the hose off

61tony

Iam about 200 miles away in Minneapolis and if Ed needs some part locating help call my shop at 612-922-5846 ask for Tony. I have 4 928's and spare parts if I can help out some how. good luck

SharkSkin

Sounds like the voltage regulator is done. Some can be replaced by a reasonably well-stocked rebuilder(first pic), some not so much(second pic). A mid-80's Audi 5000 alternator(first pic and third pic, right) will work at least well enough to get you home -- pretty much plug and play, though you may need a different belt and they charge poorly at idle. Pics below of the one I took out of my car. DON'T get the Delco in the bottom shot -- no way in hell will it charge at idle.





The pod lights will come on any time the key is on. No worries there. If they do not turn off with the key off, that is another matter.

It seems that no discussion of relays is complete without a link to the 928 Specialists fuse/relay chart.

The seat belt relay (IX) could be making the buzzing, I see here that your car still has one. Yank it out and throw it under a passing 18-wheeler. Then get the alternator fixed, check fluids and put the hammer down. It's a '78, that's even better than using Amsoil.

karl ruiter

On a CIS car during the day you pretty much just need to run the ignition and fuel pump. If somebody can measure what that draws (should not be a lot) we could calculate how far he can go on a freshly charged battery. My thought is that he can just buy a couple of fresh and fully charged batteries and a couple of chargers. Drive until the first battery starts to go down, then switch. Recharge both at night. Kinda silly, but might be easier than trying to get it fixed in the middle of nowhere.

jpitman2

My 83 CIS pump pulled 7A when I tested it once.
good luck.
jp 83 Euro S AT 52k

SharkSkin

'78 cars may have TWO pumps. I think the cars with an in-tank pump may draw a bit less overall, but most seem to have the two large external pumps. So make that 14A.

Also, the brake lights draw significant current as does the aux fan -- so traffic would kill the battery much faster, and is not easy to plan for in unfamiliar territory.

The Audi alternator would cost less than two batteries and two chargers IMHO, shouldn't be nearly as hard to find as a 928 alternator and could be installed with the tools in the tool panel(if they are there). There is still the possibility of just swapping the voltage regulator. Plus, Ed could enjoy the rest of the drive.

rixter

78s, especially early ones have 1 pump and 1 accumulator

123quattro

I have done this before for hundreds of miles with big deep cycle marine batteries.

AO

If you do this, try not to run any of the accessories (lights, radio, AC, etc.) so as to maximize your range.

Giovanni

Charge the existing battery + Buy a new battery - (Time 1st battery is drained/Place to Recharge drained battery) = Make it home safely

Landseer

Delco option may effective in this case.

Good luck, Ed.

Keep us posted / tell us what you need.

linderpat

Thanks guys - I found an internet connection. All of this is most helpful.
I got the car to a Bosche authorized service center - place called Classic Import Repairs. Not sure if it's the same contact you have Donald. This shop looks good, and he has at least 8 or 9 P cars in there, including 2 912s, Boxters, a 968, and several types of Carreras. He told me he owned several 928s in the past. I believe him (have your guy call me anyway Don in case this guy can't get to it today I'm at four-oh-six-581-73one-six).
He tested the post, and the charge is 12.2 volts, and it isn't charging. The alternator on the car is a rebuilt Bosche unit, put on last year in May. When it was installed, the meter on the dash showed only 12 volts, but the po told me that the charge measured 14 or so at the alternator post. The mechanic told me this is common? Not sure why it would dod that. Anyway, I ran for over a thousand miles and 2 days, and the needle never moved off that reading until last night - the battery stopped charging.
As to driving with extra batteries, no way will I do that out here - this is the most remote part of the country I have been to. From this city to Rapid City is 333 miles, with absolutely nothing in between. Same as the next leg to Billings, MT. Once you're past Sioux Falls, you're screwed if you have a problem. So here I'll sit until it's fixed
I'm lucky to have found an apparant qualified place tho.

linderpat

Thanks for the info Dave. I hope it's just the regulator. The guy looking at it thought it might be too. We'll see.
As to the pod cluster light, I never noticed that with my other sharks - so it stays lit all the time? Why? Wouldn't this burn out the bulbs? It does go out when the key is off.

Marine Blue

Unfortunately I can't add much other than good luck getting things straightened out. Hope its a quick fix and your back on the road quickly. Please keep us posted.