OT, I know, but you guys know stuff

This is wildly off-topic for RAMJ+W and my abject apologies are offered.
My address above is valid if you prefer to reply off-group. I'm only
asking here because you guys know your stuff, I trust you and I don't do
this very often.

I'm helping a friend with his motorhome, which was built on a 1990 GMC
chassis with a big-ass V8. I know that it had a reverse-polarity
episode with a completely dead battery and some poorly-designed jumper
cables (black cable ends in red clips, yellow cable ends in black clips,
a mistake just waiting to happen). A new battery later it cranks but
does not start. I haven't seen it in person yet.

I'm guessing that the reverse voltage took out the ignition computer,
would this be likely? I plan to meter the coil primary side and look
for voltage and pulsing during cranking to be sure. Anything else
likely to have let out a little Magic Smoke, like alternator diodes or
voltage regulator? I'm hoping to prevent cascading failures once I get
it started.


Thanks in advance,


Lee

"Lee Ayrton" > wrote in message
...
>
> This is wildly off-topic for RAMJ+W and my abject apologies are offered.
> My address above is valid if you prefer to reply off-group. I'm only
> asking here because you guys know your stuff, I trust you and I don't do
> this very often.
>
> I'm helping a friend with his motorhome, which was built on a 1990 GMC
> chassis with a big-ass V8. I know that it had a reverse-polarity
> episode with a completely dead battery and some poorly-designed jumper
> cables (black cable ends in red clips, yellow cable ends in black clips,
> a mistake just waiting to happen). A new battery later it cranks but
> does not start. I haven't seen it in person yet.

My bubba did this to a '86 Toyota PU I gave him... took out the big
40A fuse and the ignition module. $50 at the junkyard for a used
module and it runs again... if you're dealing with injection, the computer
for that probably smoked too.
__
Steve
..

Very likely he took out the fusible links at the starter solenoid.
These are 8" long soft rubber wires that connect to the harness with big
fat crimp connectors.

You can buy the wire in bulk either by the color or gauge and the
replacement needs to be crimped in. They are typically 2 gauges smaller
than the circuit they protect. If the ignition circuit is 10 ga., the
link is 14 ga.

This happens in Jeeps as well if someone boosts wrong.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Lee Ayrton wrote:
>
> This is wildly off-topic for RAMJ+W and my abject apologies are offered.
> My address above is valid if you prefer to reply off-group. I'm only
> asking here because you guys know your stuff, I trust you and I don't do
> this very often.
>
> I'm helping a friend with his motorhome, which was built on a 1990 GMC
> chassis with a big-ass V8. I know that it had a reverse-polarity
> episode with a completely dead battery and some poorly-designed jumper
> cables (black cable ends in red clips, yellow cable ends in black clips,
> a mistake just waiting to happen). A new battery later it cranks but
> does not start. I haven't seen it in person yet.
>
> I'm guessing that the reverse voltage took out the ignition computer,
> would this be likely? I plan to meter the coil primary side and look
> for voltage and pulsing during cranking to be sure. Anything else
> likely to have let out a little Magic Smoke, like alternator diodes or
> voltage regulator? I'm hoping to prevent cascading failures once I get
> it started.
>
> Thanks in advance,
>
> Lee

Hi Lee,
If you have a specific question, like the continuity between A and
B, I'll make trip over to my Son's home, as he has a square block in
his, too: http://members.aol.com/LarrHughes/ocot31905.jpg Blows the
doors off his Father-in-law's new Dodge diesel:
http://www.billhughes.com/temp/diesels.mpg
God Bless America, ßill O|||||||O


Lee Ayrton wrote:
>
> This is wildly off-topic for RAMJ+W and my abject apologies are offered.
> My address above is valid if you prefer to reply off-group. I'm only
> asking here because you guys know your stuff, I trust you and I don't do
> this very often.
>
> I'm helping a friend with his motorhome, which was built on a 1990 GMC
> chassis with a big-ass V8. I know that it had a reverse-polarity
> episode with a completely dead battery and some poorly-designed jumper
> cables (black cable ends in red clips, yellow cable ends in black clips,
> a mistake just waiting to happen). A new battery later it cranks but
> does not start. I haven't seen it in person yet.
>
> I'm guessing that the reverse voltage took out the ignition computer,
> would this be likely? I plan to meter the coil primary side and look
> for voltage and pulsing during cranking to be sure. Anything else
> likely to have let out a little Magic Smoke, like alternator diodes or
> voltage regulator? I'm hoping to prevent cascading failures once I get
> it started.
>
> Thanks in advance,
>
> Lee

>L.W. Hughes III (=DFill) wrote:
>Blows the doors off his Father-in-law's new Dodge diesel:
> http://www.billhughes.com/temp/diesels.mpg

Hmmm, I just downloaded a 5+ MB file to see 31 seconds of your family
vacation pictures?

I've got to work on the Jeep more and surf this newsgroup less.

http://mandyky.tripod.com/addict.html
God Bless America, ßill O|||||||O
http://www.billhughes.com/

wrote:
>
> Hmmm, I just downloaded a 5+ MB file to see 31 seconds of your family
> vacation pictures?
>
> I've got to work on the Jeep more and surf this newsgroup less.