aldl stuff

[Peter Gargano]

Mike Swayze wrote:
> 
> managed to get the max232 ALDL interface soldered up this past weekend, just
> need to put it in a box and try it out. I was wondering if one of the ALDL
> connector pins is hot as in +12V, ...

Mike, from past discussions, there *are* some US vehicles that
don't have 12V on the connector. So, most people use the lighter
socket, or the modem signal driver circuitry diode arrangement.
Both Andrew M and I have documented this change, and some people
have found that low power laptops have had problems supplying
the modem status line power for a MAX232.

>... only thing I had read in the archives was
> about one of them only being hot when the transmission was in neutral  (or
> something like that).

That's because someone connected to one of the ECM's outputs
that was only at 12V sometimes!

BTW. it seems all Australian ALDL connectors do have permanent
12V available.

HTH, Peter
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