Oh ****! +12v to chassis via cd-changer...

[Dan in NZ]

I just made the last connection to power my cd changer. I hit eject, and nothing happened, so I checked the inline fuse I had just installed (wire in glass tube type) and the wire had vaporised... For about half a second I touched the wires together, and instantly felt the 1.0mm plastic covered wire get hot.

The wire was hot the whole length, right up to the cd changer.... The negative wire I ran was still cold, so I'm hoping like hell I just managed to earth the cd changer chassis through it's mounting bolts...

I did a search before I made the final connections and other people had used the outer pin for +12v, and the inner one for ground. I wonder why this didn't work for me??? Should I swap them over???

I really hope I haven't fried my cd changer...

[632 Regal]

damn man that sucks. I like mine stock because of this reason lol. You say the outer pin and inner pin, you mean on the CD player or what? Did you double check them with a volt meter to see whats what?

[Dan in NZ]

Phew!.. Swapped the pins over, and it works just fine... Feeling a cable get instantly hot in your hand, knowing that one end is attached to your cd changer is not a good feeling.

632 Regal, I like my car stock too. Well, the best version of stock. I'm upgrading my stereo from the 1989-1990 version to a 1991+ version, and installing the cd changer. My car is pre-1991 so it's not prewired for a cd changer, I have that +12v cable running from the fusible link under the back seat.

So now I have the cd changer installed and powered, I just need a head unit, data cable and bmw-pio/m interface cable, and I'll be listening to cds!

[632 Regal]

I'm glad it's not. Time to get some more CD's!

[Jon K]

Phew!.. Swapped the pins over, and it works just fine... Feeling a cable get instantly hot in your hand, knowing that one end is attached to your cd changer is not a good feeling.

632 Regal, I like my car stock too. Well, the best version of stock. I'm upgrading my stereo from the 1989-1990 version to a 1991+ version, and installing the cd changer. My car is pre-1991 so it's not prewired for a cd changer, I have that +12v cable running from the fusible link under the back seat.

So now I have the cd changer installed and powered, I just need a head unit, data cable and bmw-pio/m interface cable, and I'll be listening to cds!


If the CD changer wasn't grounded the wire wouldn't have become hot. But now you know that you don't touch two wires together after they've blown a fuse. When you start to play with more expensive electronics this becomes very evident. Be safe! If you ever think a fuse is too lower amperage, up it up 10 or so, if its a ground short, it will STILL blow... without ruining the player (usually).

[Mobius]

If the CD changer wasn't grounded the wire wouldn't have become hot.The CD changer very likely also gounds via its chassis.


Be safe! If you ever think a fuse is too lower amperage, up it up 10 or so, if its a ground short, it will STILL blow... without ruining the player (usually).Er, not safe. :) It's never really a good idea to start increasing the size of the fuse, as the fuse is there to protect wiring of lower resistance. If the fuse is of less resistance than the wire, then you may still have a short, and the fuse will not blow. Now you've got a hot wire that's melted the harness all the way back to the main fuse block. (ask me how I've seen this happen first hand)

Don't put a larger fuse in a holder unless you're absolutely certain all the wiring in the circuit can handle more current than the fuse can.

The safest way to test for a short is to test for continuity between the positive wire and ground (with a multimeter). Try to isolate the wire from other electronics as much as possible to get the most accurate results (pull the fuse on one end and disconnect the changer from the other end) - otherwise you'll be sensing trace continuities through other circuits and such.