My 1991 Z28 has a little cylindrical shaped black plastic "thingy" on the thinner red wire from the battery with three more thinner wires coming out of it, one of them being orange. This orange wire burned up when I turned on the A/C to check its operation (first time I turned it on since I've bought the car two weeks ago).

The main red wire (wrapped in the loom) continues to the alt. The thin red wire and thin orange wire go to a big honking connector just a few inches aft of this black "thingy".

From what I found in the manual, this is supposed to be the ECM memory wire. But why would it burn out with A/C on??

Any ideas what to check?

Trickster, would you have a better diagram for this thing? I don't know exactly what it's for and what the black cylindrical "thingy" does.

Thanks in advance for any help.
Lou

 

That is one of the fusible links from the battery post, that one either goes to the fan relay or the in-line fuse for the ECM, fuel pump relay, and fuel pump/oil pressure sending switch. Here is a picture of it.

 

Thanks Trickster!
Yes, the red wire from this thing goes to the fuse on the pass fender. That fuse controls the power to the relays for fans and fuel pump (guess how I know? )
When the orange wire burned up, the engine would still start and run so it might be only a "memory" wire for the ECM, not the actual power wire.
Any idea why it burned out when I turned on the A/C? SHould I try again?

Thanks
Lou

 

You probably have a short at either the fan or the fan relay.

 

Yup, that's one thing I'm looking into. Not a short but the fans weren't working with the original wiring and the PO just ran two wires with gazillion of splices from the fusebox directly to the fans to keep 'em turnin'. Horrible. See pictures here: http://community.webshots.com/album/186862302oqEwAZ

Thanks
Lou

 

Holy ding! ding! Batman!!!!!!!!!!!! OUCH!!

 

Ok, I'm sorry, didn't mean to blind you (hopefully only temporarily).
Here, something to make up for it: http://community.webshots.com/album/187680656oLcMrj?768

Lou

 

Now that is much better looking on the outside than it was on the inside!!

 

You've got PM.