electrical problem 636csi

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   Hi
  I have a 1982 635CSI which is driving me nuts. Unfortunately it will not start. The engine turns but wont fire. When this occurs there is no spark either. However on other occasions the car will start normally with no problems. Even more strange is that when you turn the key in the ignition the windscreen wipers and washers often come on. This only happens when the car won't start. Does anyone have an idea on what I should do to get the car started.

with thanks

Edward

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eclayson Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 06-June-2005 Status: Offline Points: 2	Topic: electrical problem 636csi Posted: 06-June-2005 at 17:21
	Hi I have a 1982 635CSI which is driving me nuts. Unfortunately it will not start. The engine turns but wont fire. When this occurs there is no spark either. However on other occasions the car will start normally with no problems. Even more strange is that when you turn the key in the ignition the windscreen wipers and washers often come on. This only happens when the car won't start. Does anyone have an idea on what I should do to get the car started. with thanks Edward

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Howard Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Moderator Group Did I say thaaaat? Joined: 14-October-2002 Location: United Kingdom Status: Offline Points: 735	Posted: 06-June-2005 at 17:41
	Sounds like an earth fault somewhere. Check that the copper earthing strip that is bolted between the chassis and the engine block has not corroded away or come loose at its fixing points. The 635 is quite complicated wiring wise,and has lots of connections that can go temporarily disconnected. If you have some time to spare, get a good quality contact lubricant (not WD40, which is good for some things but not for this)and disconnect the connections, clean and lubricate them, and put them back again. The fault indictor panel is often a culprit in silly electrical faults. If the worst comes to the worst, then take it to an auto-electrician. May pay in the long run.
	1963 700 LS 1988 635 CSi 1990 M635 CSi no longer! 2001 E38 728i Individual http://www.tyneships.co.uk

eclayson Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 06-June-2005 Status: Offline Points: 2	Posted: 06-June-2005 at 17:44
	Hi Thanks for the advice. Is the earthing strip just in front (toward head light) of the fuse box, attached to the inner wing?. There are a group of cables that go to this point which all look pretty grubby thanks Edward

siscobmw Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member II Joined: 13-May-2005 Location: North Italy , near lake of Como Status: Offline Points: 201	Posted: 10-June-2005 at 12:58
	If you have a 1982 "second series "car , with OBC : The OBC has got an alarm code, with a relais, inside the OBC brain...You can use it or not, but this relais will seize (oxidation, age....). I tried on a spare OBC ECU the way to solve the problem..But It's too complicated for "my ECU"(it starts in the morning till the night, without code... ) The only thing I have done is to apply 1 Bypass to this relais. I have access to some electronic troubleshooting manual for BMWs,so I located wirings that trigger relais and code. If You look at the the OBC brain, You can see two connectors,a black one and a yellow one.Look at black connector and locate wires no14 and no15 ( on the connector You can also see the numbers of wires, stamped with very little font) and I made a 5 cms jumper ... The OBC alarm code is disabled forever( unless you have a second hand ECU), but I ensure you that this relais get worse and You will find yourself( it happened to me) on the highway, at a "dont-mention" speed , and this stupid stuff cut out....I't s not fun. one other culprit: from above the glovebox, where the Motronic OBC is located , you can se 1 or 2 3wires-connectors a black one and a white one . from the white one You can see a little green wire...It's the one which feed main relais(It comes from battery and goes to ignition key, it goes into On Board Computer brain and then, after the alarm code, it goes at last to one pin of main relais, attached on the fuse box). it's so heavily pressed to wiring loom (under the isntrument pod) with plastic collars, that after 23 years it' could be worn and make a short somewhere( in your case it's the washer-wiper system, in my case the horns)...Remove the instrument pod and search this wires( it runs parallel to the bigger wiring loom under the dashboard, it goes into black connector of OBC brain -number 14 or 15- and you cen see it near the Motronic ECU. I hope that this helps. Francesco from north Italy