Help, alternator grounded out?

El Hombre

Amateur Racer
May 24, 2003
235
0
0
Roanoke, Virginia
I was getting excited to get my 78 Malibu back to running when I touched the alternator wire to the casing. A startling pop occured, and I realized I left the battery wired up. #-o continued to finish putting it all back together anyway.

Now all dash lights, cabin and outside lights, ignition power, everything is not working... Anyway I thought maybe it blew fuses out, I checked the fuse box and everything is okay. I can't find any sort of relays or fusable links on this car so I thought "Maybe I grounded the alternator?" Took it to get checked at the auto store, their equipment says it passed fine.

Has anybody ever had this experience? I figure it cannot be too hard to find, it's a fairly simple older car. So far the wire looks fine where I traced it, but only to where it goes up under the firewall, at the top of the transmission, then it gets pretty tight in there and I can't see.
 

El Hombre

Amateur Racer
Thread starter
May 24, 2003
235
0
0
Roanoke, Virginia
Also when I remove the negative terminal from the post and put it back on it there is a little spark so it seems to be getting power fine.
 

Doober

Moderator
Jun 2, 2003
14,704
1
38
Catalina, AZ
www.cardomain.com
Did you check the fusible links? They're typically down on the starter.
 

El Hombre

Amateur Racer
Thread starter
May 24, 2003
235
0
0
Roanoke, Virginia
Fixed it, thanks Doober! I curiously decided to charge my battery while checking out the solenoid wiring, and there seemed to be some odd rubber piece wrapping itself around the main wire, which was pretty random. May have caused everything. Got that off and wired everything back up after inspecting the wire conditions. Wired the battery back up when it was done charging and it all worked again. It's alive!
 

Doober

Moderator
Jun 2, 2003
14,704
1
38
Catalina, AZ
www.cardomain.com
No problem :)
The OE fusible link looks like this, a small plastic/rubber cylinder around the wire:
2010-07-31_142709_GM_fusible_links_sm.jpg


Sometimes if it's been replaced and burns up it looks like this:
Fuselinks.jpg


If you don't have a fusible link or fuse in-line here, you risk a fire if it grounds on something.
 

NOT A TA

Frequent Racer
Nov 30, 2009
346
1
16
Delray Beach FL
El Hombre said:
I'll definitely keep this in mind and thank ya!

Don't just keep it in mind, install a new fusible link. NOW. It saved you last time from possibly melting wires and you might not be there if there's ever a next time. That piece protects all the wiring (except the battery cable) in your car that has power all the time (even with key off).
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
1
38
North Jersey
Doober said:
I think for mine I'm going to do a fuse block for each of the wires... beats splicing in another fusible link imo.

You can't replace a fusible link with a fuse block. Fuses are not designed to operate under the same short term high loads a fusible link can handle without blowing. If you get fuses big enough to handle the load, you're inviting a fire...

Tommy
 

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