mrdieseldude

I bought my fixer and the the guy told me the battery drains after a few days... I figured I could figure it out. Well, now I'm beginning to wonder. This one is right down the Landseer's ally:

With all of the fuse pulled and all of the relays pulled from the electrical panel, I am drawing 75 mA. I have not checked the other relays that I think are hidden around the car (and maybe a fuse ???), but I have at least narrowed it down a bit to challenge the crowd. Any thoughts? I would think zero draw with all of the fuses and relays pulled. I even yanked out the old alarm and put the wiring back to original. Am I missing something?

Jim M.

Lets start with the year and transmission type of your car. Also what optional equipment does it have?

mrdieseldude

Jim, at the risk of sounding like the complete newbie, it is an '88 with auto trans. Other than that, I did not get a build list, so I am going to sound like a d.s. and say it has the rest of the typical goodies... sun roof, power everything. No rear A/C... other than that I can't say. I don't even know what a typical static load should/would be on this gill'd animal.

Mrmerlin

at the top of the page,
click on user CP,
then click on edit signature,
then fill in the info about your car,
year, color, trans,
any options,
then every time you post your info comes up as well

for the drain it might be the alternator/regulator if you pulled out everything from the CE panel

docmirror

I"m going to go with the old standby -- radio. Wired in by a PO, and bypassed all fuses.

Another way to start thinning the heard is to disconnect each of the connectors around the edge of the CE board one at a time, and watch the meter. When you get one off that shows a decrease in the current, start tracing the wires on that connector.

Mrmerlin

thats a good idea Doc

WallyP

To remove the connecting plugs from the later Central Electric Panel, locate the handle for the plug lock near the center of the row of plugs. Slide the locking mechanism to the side, then carefully pull the connector from the CE panel while lifting the small locking tab above the connector.

jeff spahn

What Wally said, cause the little locking tabs break off pretty easily.

mrdieseldude

Thanks Gents, and to Mrmerlin for the signature tip. I never could figure that out... must be getting old.
Anyway, got the CEB apart and found a wire with insulation burned completely off. Looks like I am in for a bit of a project. Now I am finding that I am having MAJOR problems reading the electrical drawings. I don't mean tracing the wire lines (which is hard enough), I mean reading the notations that are listed next to the connectors and relays is really tough... more like smudges in some cases... these photographed drawings just don't blow up right. Is there a trick to this that I am missing? Short of being lucking enough to have an original hard copy, this has got to be tough for everyone.

MainePorsche

Having the original Wiring Diagrams/Workshop Manuals is of course optimal.
Go to 928-electrics.com then the Wiring Primer button. This is by Alan, and is a very good tutorial.

mrdieseldude

Thx MainePorsche. You read my mind... this link is perfect for decyphering these drawings. Now all I've got to worry about is the smudge like marks. At least it will be a big help to know what I should be expecting to see.

mrdieseldude

I want to report back the problem for the "WIWF" (what it's worth file), but first thanks to you guys with the great tips and diagnostic suggestions. I thought I could read a drawing, but MainePorsche's link really filled in the blanks. Wally's tip on how to get the connectors out saved a lot of broken parts and gave the confidence to pull the entire CEB out. Behind it was the remains of an old security system. After the better part of a day getting it out and the wiring patched back together proved to be 40 mA of the problem. Now, this leaves me wondering:

What is the normal idle load on the 928 supposed to be? I am seeing 35 mA after the alarm was removed. I suspect some parasitic load will exist (clock, etc.), but I haven't a clue as to what might be considered "normal". Maybe I am splitting this hair to thin... after all, that first battery was a POS, maybe it was the problem all along???

blown 87

I agree, it even helped folks that do this for a living understand a few extra points.

I hope the full version is available soon, it will be worth the 55 bucks.

docmirror

I think resting current of the 928 is around 3-5mA. You've still got some work to do. Glad you found the alarm system. That's another big one. Now that you have the CEB disconnected, go back and put one connector on at a time while monitoring the current flow. It may be split between several connectors, but you can hunt it down if you found the alarm. That's better than a lot of people. Hang in there you'll get it all.

MainePorsche

Also, there are two low amp in line fuses behind the CE board for the doors. They are not in the owners manual but can be seen in the door circuitry in the WD's.