Got a head scratcher... Turned off the engine of my '88 M6, removed the key and multiple accessories still are powered, including radio, antenna, wipers, turn signals, and left side warning panel. Ordered and installed a new OEM ignition switch, and it works perfectly. All the key positions seem to power up the proper items and engine starts and turns off with proper key positions. The new switch made no difference to the still powered items. Have consulted the trouble shooting electrical manual, and pulled and replaced various fuses that effect the items that remain powered. Also replaced the 2 power module relays. Pulling fuses for the wipers for example does not keep the other items from remaining powered. Have installed a battery kill switch incase the computer or other silent items are getting unauthorized power. Car starts, runs, and stops normally. Any thoughts would be appreciated? I hate electricity issues!
Thanks
relay is sticking. idk which one or where,but that's probably whats happening.
Pull the relays one by one to see if that's the problem.
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+1 on stuck relay.
I'm going with a minority opinion...my bet is a worn ignition lock cylinder or barrel. Might be that the little twisty thing inside the steering column might be turning the ignition switch "forward" (off->acc->run->start) properly, but not turning the ignition switch "back" all the way (start->run->acc->off). I've also seen a few times where the cylinder isn't fully engaged in the barrel, and it can move laterally enough for sloppy engagement.
If it ends up as a mechanical lock cylinder issue, it's not a huge deal. Taking the column apart isn't a whole lot of fun (I especially detest those snap off anti-theft bolts), but it's all just mechanical stuff. IMHO it beats chasing down electrical gremlins...
Save the manuals!
'08 128i 6MT, '86 635CSi 5MT (B32, Motronic 1.3, WBO2, G265, 18# FW, 3.46 torsen)
Past projects:
'96 318iS, sold 4/23 '90 535iM, RIP 1/23 '90 535iA RIP 6/22 '91 318i, sold 7/19 '97 M3 sedan, sold 11/18 '85 735i, RIP 2/18 '92 325iC, sold 7/16 '91 318iS, sold 6/16 '84 745i, sold 10/14 '82 633CSi, traded 9/12 '90 325i, RIP '87 325 sold '89 525i, traded '87 325iS, RIP
After pulling the steering wheel and replacing the ignition switch, (and of course not exactly recentering the wheel when finished), Think I'm going to take a handful of new relays and try that. Most relays for the M6 are either in the fuse box, or behind the glove box. Are there any other suspect relays that reside in out of the way places? Has anyone had the large wiper relay fail?
When you say that you replaced the ignition switch what did you replace? The ignition switch is the part with the wires attached.
e28 ignition switch.jpg
The rectangular plug is the C200. The violet wire is pin 9 it supplies the fuse box. It provides 12v+ to the wipers, radio and others that you mention. The red wire is pin 4. The switch connects the red and violet wire in Acc, run and start.
If there is 12v+ positive at the violet wire with the key out then the ignition switch is faulty. There should be not continuity between red and violet with the key out.
Check at the steering column with a multimeter.
We assumed the switch was changed (installed a new OEM ignition switch), that's why a stuck relay seemed a possibility. Looking @ the ETM, pages 0670-3 & 0670- Can't find a relay that could possibly stick.
I think jmpower is on the right track. I would meter test the ign harness switch to make sure the there's no power to the 3 circuits that show from the switch on page 0670-3.
7https://www.millerperformancecars.com/files/bmw%20electrical%20manual/1988%20BMW%20635csi%20-%20M6%20Electrical%20Troubleshooting%20Manual.pdf
I replaced the electrical switch that attaches to the mechanical key lock cylinder. I observed the mechanical horizontal and vertical pin movements that the lock makes in the various key positions prior to fitting the electrical switch onto the locking tabs, and suppose these are normal. I think the mechanics of turning the key are normal. Thanks for the lead on the power pins I will get a a better attitude, advil and crawl back under the column for round 2 with multimeter. Thanks!
If you replaced the switch then you would assume that it works. If you test as I described there should be no continuity between the red and violet wires. The best way to do it is with the switch in place first and then again with it disconnected. This removes the assumption and it works or it does not. (Try your old one first)
When you fitted the switch it should be fitted with the key in the Accessory position the switch should not fit in the off, run or start position.
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