I had some work done on my car locally which involved dismantling the rear suspension. A few months later (and it took several months to show itself), I started having strange alternator/battery problems. The alternator didn't seem to charge well at all but a test on my diagnostic machine showed it to be perfect. The battery would often die for no apparent reason and the car often wouldn't start. I eventually found the problem to be an improperly routed ground strap. The ground strap to the engine (the only one, as far as I can see) is hooked to the bolt that holds the lower suspension link on the driver side of the car. It should go from that bolt to a bolt on the transmission. It should NOT go to the motor mount. The mootor mount is made of rubber and won't provide a ground. This is why the strap is there in the first place. The mechanic had reconnected the strap in such a way that the engine was grounding to itself! I wasn't able to move it (stripped nut..maybe why he didn't put it back.) so I installed a second grounding strap running from the trailing arm bracket bolt where the negative battery cable connects to one of the starter motor bolts. Works like a charm! --Rob Hook -----Original Message----- From: Mike Substelny [SMTP:msubstel@xxxx] Sent: Monday, February 14, 2000 11:39 AM To: dmcnews@xxxxxxxxxxx Subject: [DML] Re: alternator troubles DMC Joe said: > If the battery is week the alternator will increase the output > voltage. When the alternator sees no voltage from the > battery (battery disconnected) it will run "full bore", this can > cause serious and or permanent damage to the alternator and > or other electronic components. If you have an auto trans this > over voltage can damage the computer governor. My expertise is miniscule compared to DMC Joe's, but I think the situation is even worse than he describes. As I understand it, the alternator does not put out nice, smooth DC current. It puts out a DC wave pattern, and the car's electronics were designed with the assumption that a battery would always be in the circuit to smooth out that wave. This should not harm motors (e.g. fuel pump), relays, or light bulbs, so disconnecting that battery might have been a good diagnostic for cars in the 60s. But if I am right, this test could seriously damage any solid state components in the car, including the computer, the radio, any 'Zilla parts, etc.. If I am wrong someone please correct me. I am pretty confident that running a DeLorean with the battery disconnected is a BAD idea! Donald, your messages have not mentioned the reading of your voltmeter during this adventure. If your alternator is not working at all, then "gunning the engine" as you described last Wednesday should not have worked. Consider the possibility that you might have a more subtle problem. Perhaps a bad ground wire somewhere is gobbling up just enough current that your battery must discharge to keep the engine running any time you are at low RPMs. - Mike Substelny ------------------------------------------------------------------------ Before posting messages or replies, see the posting policy rules at: www.dmcnews.com/Admin/rules.html To address comments privately to the moderating team, please address: moderator@xxxx ------------------------------------------------------------------------ eGroups.com Home: http://www.egroups.com/group/dmcnews/ http://www.egroups.com - Simplifying group communications