Subject: Re: Newbie, E34 problems Author: ddavison512 : member since October, 2008 : 12 posts Posted on: 2009-01-08 14:20:13

Follow up to the above.

The low voltage on the D+ terminal does not seem to be the problem. The repair shop I took the car to did the same test to another ( next platform, not an E34, but the similar ( E60? ) ) car, and it showed the same ( actually lower ) voltage. Which makes sense, if that wire were meant to carry the higher voltage, I would expect it to be the same gauge wire, but it is not, it is much thinner.

So, I had the shop replace the power distribution block in the steering column. That did not help, car still had same behaviour.

They had me drive the car till I got the Anti Lock light on. Then I was to check the voltage at the charging point in the engine compartment. It was low, about half what it should be ( my VOM dial is not very good... ) with the engine running. They told me it had to be the alternator, so I let them replace it. Drove it yesterday, and guess what? It failed again.

I get a good light in the dash for the alternator/battery, so I don't think that is preventing charge getting through.

3 separate alternators have been in the car, same behaviour with each, so I don't think it is the alternator.

So, I think I am back to the original diagnosis that there is a short ( I would imagine that that would draw the voltage down? Correct me if I am wrong ).

So, how do I find a short? What can I use to detect where it is?
The voltage is low at the charging point, does that help isolate where it is?

Thanks in advance.

• Newbie, E34 problems - ddavison512 2008-10-10 21:11:19 (294 views)
  • Re: Newbie, E34 problems - rick540 2008-10-19 03:52:15 (155 views)
    • Re: Newbie, E34 problems - ddavison512 2008-10-19 23:42:49 (129 views)
  • Re: Newbie, E34 problems - Shayne 2008-10-10 22:16:03 (195 views)
    • Re: Newbie, E34 problems - ddavison512 2008-10-18 21:31:56 (131 views)
      • Re: Newbie, E34 problems - ddavison512 2008-11-08 19:01:53 (113 views)
        • Re: Newbie, E34 problems - ddavison512 2009-01-08 14:20:13 (77 views)
          • Re: Newbie, E34 problems - ddavison512 2009-01-24 16:59:36 (73 views)
            • Re: Newbie, E34 problems - ddavison512 2009-04-10 18:34:38 (42 views)
      • trunk wiring - Jerome 2008-10-19 02:02:02 (139 views)
        • Re: trunk wiring - ddavison512 2008-10-21 20:24:25 (136 views)
        • Re: trunk wiring - ddavison512 2008-10-19 23:35:58 (118 views)
        • Re: trunk wiring - ddavison512 2008-10-19 03:10:53 (125 views)
    • Re: Newbie, E34 problems - ddavison512 2008-10-11 01:17:06 (142 views)