What's up here

[Gary Jarlson]

A friend has offered me his 1983 635 for free. It's a gray-market car (the owner's manual is in German.) The car itself is kind of rough. The bodywork seems pretty good. No rust, although the paint has a few problems on a front fender and the hood. The interior really needs help.

My first question involves the battery (http://rover.ebay.com/rover/13/0/19/DealFrame/DealFrame.cmp?bm=825&BEFID=87204&acode=892&code=892&aon=&crawler_id=518814&dealId=0vrMrumOUz20CEIENv5IZw%3D%3D&searchID=&url=http%3A%2F%2Fc.affil.walmart.com%2Ft%2Fcsesh01 %3Fl%3Dhttp%253A%252F%252Fwww.walmart.com%252Fip%2 52FINSTEN-2-LP-E10-Battery-Charger-Neck-Strap-for-Canon-Rebel-X50%252F32243414%253Fwmlspartner%253Dshoppingcom%2 526affcmpid%253D1845892272%2526tmode%253D0000%2526 bcfg%253De96184b032f01c1b9788442d713a8b79%2526veh% 253Dcse&DealName=Insten%202x%20Rechargeable%20Battery%2010 20mAh%20%2B%20Car%20%2B%20Travel%20Charger%20%2B%2 0Neck%20Strap%20for%20Canon%20EOS%20M%201100D%20Re bel%20T3%20T5%20Kiss%20X50&MerchantID=518814&HasLink=yes&category=0&AR=-1&NG=1&GR=1&ND=1&PN=1&RR=-1&ST=&MN=msnFeed&FPT=SDCF&NDS=1&NMS=1&NDP=1&MRS=&PD=0&brnId=2455&lnkId=8070676&Issdt=161222051507&IsFtr=0&IsSmart=0&dlprc=22.49&SKU=32243414). There isn't one. When I gave the matter a quick once over, something struck me as odd. There is a red cable goes from the battery (http://rover.ebay.com/rover/13/0/19/DealFrame/DealFrame.cmp?bm=825&BEFID=87204&acode=892&code=892&aon=&crawler_id=518814&dealId=0vrMrumOUz20CEIENv5IZw%3D%3D&searchID=&url=http%3A%2F%2Fc.affil.walmart.com%2Ft%2Fcsesh01 %3Fl%3Dhttp%253A%252F%252Fwww.walmart.com%252Fip%2 52FINSTEN-2-LP-E10-Battery-Charger-Neck-Strap-for-Canon-Rebel-X50%252F32243414%253Fwmlspartner%253Dshoppingcom%2 526affcmpid%253D1845892272%2526tmode%253D0000%2526 bcfg%253De96184b032f01c1b9788442d713a8b79%2526veh% 253Dcse&DealName=Insten%202x%20Rechargeable%20Battery%2010 20mAh%20%2B%20Car%20%2B%20Travel%20Charger%20%2B%2 0Neck%20Strap%20for%20Canon%20EOS%20M%201100D%20Re bel%20T3%20T5%20Kiss%20X50&MerchantID=518814&HasLink=yes&category=0&AR=-1&NG=1&GR=1&ND=1&PN=1&RR=-1&ST=&MN=msnFeed&FPT=SDCF&NDS=1&NMS=1&NDP=1&MRS=&PD=0&brnId=2455&lnkId=8070676&Issdt=161222051507&IsFtr=0&IsSmart=0&dlprc=22.49&SKU=32243414) area back under the intake and in the general direction of the block. The cable end at the battery also has a braided pigtail (in my experience a grounding device) that attaches to a post on the inner fender. The black cable, on the other hand, joins into a wiring loom that travels along the inner fender and then around to a point where it seems to enter the firewall. The cable end has several wires, including one that looks like an in-line fuse, attached to it.

It seems the norm--red cable positive, black cable negative--has been reversed. I'm very hesitant to connect up a new battery with this seemingly backwards layout. I'm certain the results, whatever they are, could be unpleasant.

[rlkrlk]

Um, yeah. A braided, un-insulated cable should be ground. Better look closely at the cables/wiring before hooking things up tho, to be safest.

Post pics.

Chees,

Ray

[Sprocket]

Neg on my car (Euro gray-market) is the cable that is closest to the fender (on the left if looking from the rear of the car).

[DesktopDave]

Just like Sprocket, on all my E24s (Euro or NA), the outer cable was ground/negative, grounded to the chassis on the front inner fender wing with a braided strap. Inner cable was positive. The positive cable is a bunch of wires. The largest positive wires will run directly to the starter, and then connect to the alternator. A few others will run to the ABS unit and fuse box. I still have the fuse box and cables, if you'd like a few pics for comparison.

There was a large market for custom BMWs back in the day. It's entirely possible that you had a rear-mount battery box wired up to help balance out the car. IIRC the Euro M635CSi had that setup from the factory. There's a decent pic of the rear trunk-mount battery in this thread. (http://www.bimmerforums.com/forum/showthread.php?1149297-battery-relocation-to-trunk) Not a great add-on IMHO, really eats into what little trunk space these cars had. I guess if you're buying a gray-market M635CSi...trunk space isn't the biggest consideration.

Believe it or not, the 'norm' for BMW isn't the same as everyone else's. :confused The stock BMW grounding color is typically brown, it can fade to a sorta/kinda reddish color. Often, wires relating to starting the car are color-coded black or black/yellow.