Bilal928S4

Thank you for the suggestion, I will try and get to it after work tonight.
I hate electrical problems.
Bilal

Bilal928S4

OK,
Per Wally's suggestion removed the three wires from the post and the battery stayed fine. Reconnected the 2 red wires to the post and it was still fine. I connected the brown wire to the post with the big connector not connected and it started drawing and voltage started going down rapidly.
I have the wiring diagrams but do not have a clue what I am looking for.
Any help would be appreciated.
Thanks
Bilal

tmpusfugit

so where are you located? Maybe there is a fellow 928 owner who can offer some assistance....

docmirror

Yikes! Be careful here. Brown wires on the 928 generally indicate ground. It should NEVER be connected to the + positive side of the battery terminal. It may be a red wire that has been oxidized to look brown? Please double check.

Now, if you have it broken down to one wire doing the loading, then leave that off, start the car and let it idle, then go through the systems one at a time, and check off what works, and what doesn't. i.e. Headlights, high beams, horn, heater, AC, radio, int lights, seat movement, mirror movement, etc. When you find what doesn't work, report back, and we may be able to identify the supply wire, and what may be causing the drain.

neilh

Big Brown wire up at the post is usually a discolored red or yellow!

Bilal928S4

I am in CT. New Canaan CT. The wire I am talking about is the one that you disconnect at the post with the connector to do the WP/TB replacement. It is also shown on Dwayne's write up. So I know that I am connecting to the right location.

Bilal928S4

It is the brown one in this picture.

neilh

That is the main power feed from the battery / alternator up to the post, and it's RED! - then to the rest of the car !
So, unfortunately, you know the problem is back from there. I would go back to the CE panel and start trouble shooting. At this point, its better to pull the battery, unhook the big red wire, put a sensitive ohm-meter on the big red wire ( it should show a very low resistance) , and pull every fuse one by one, checking the resistance, if it suddenly jumps up, you are on the right track!

Mrmerlin

dont run the engine with any wires disconnected you will fry something else most likely the alternator or the engine computer..
NOW if your talking about connecting the brownish( actually was red) wire to the hot post then you may have a bad alternator that is internally shorted

neilh

Stan, he has no drain until he hooks up the big red wire - wouldn't that suggest the alternator is good as it is still in circuit, but the load side of the post has the problem?

Bilal928S4

So if this is the harness that goes to the panel, can somebody provide me with a picture or routing path. It could be that when I lifted the engine (by the home made 4x4 wooden brace) to replace the MM and when I set it back down I could have pinched this harness or nicked a wire and that is why I am getting a short?
Suggestions?
Bilal

Mrmerlin

the fat red wire goes to the alternator, if your showing a drain with this fat wire connected,
then you either pinched a wire when installing the alternator or it has an internal short .
anyway remove the alternator and inspect the wire harness with the rear cover removed

Bilal928S4

MrMerlin,
So if I take the alternator OFF, what am I looking inside once I take the back cover off? The buring plastic smell was comming from the other side of the engine. Also I checked the wiring to the alternator and it is not pinched. I was degreasing a lot of the stuff at the bottom of the car, some engine degreaser might have inadvertantly gone into the alternator as it was sitting on an upside down pail.
Bilal

neilh

Before you pull the alternator:
As i said earlier, you do not look for a short by continually applying battery voltage - you may make it worse. Do you have a digital ohm-meter? I'll modify the steps I suggest:
1) Disconnect the battery.
2) disconnect the big red, which we have determined goes to the alternator.
3) Unplug the 14 pin adjacent to the jump post.
4) disconnect each wire at the jump post.

hook one lead ( black) from the ohm-meter to chassis. Withe the meter on the 1000 ohm ( 1k ) range, measure and record the resistance at the disconnected reed wire, each of the wires removed from the post.
Now, reverse the leads on the meter, so red is to chassis, and repeat.

Post back and i'll give you next steps....
Neil

docmirror

No it won't. That may have been true with Ford or Euro alternators decades ago. The 928 has an internally regulated alternator, and is diode limited to 14.8VDC. It will never, ever put out any more than that. If the int regulator was damaged, it would show already with very high voltage, and bright lights, and possibly popping fuses. Disconnecting loads one at a time from the jump post is something I've done several times. It helps to isolate the supply line that is faulty.