gmsuv

I purchased a Onstar FMV Mirror to install on my 2004 and it has 3 wires to connect.
Yellow to 12V (Switched), Red to 12V (Acc), Black to G.
What I want to do to run the mirror is to tap the fuses at the fuse box in the passenger well but I do not what fuses to tap. Every post I read says to use fuse #22 but I have BCM IGN#3 in that position. Any help?

dadaroo

Being a 2004 you do not have the earlier accessory feeds. However, like you say, you can use a fuse adapter to pull from the same circuits since they still exist, just no leads feeding from the fuse box.

Do you really need a feed from ACC or will just "Hot in On" do for both?

A good ground would be the one at the A-Pillar on the passenger side.

I have helped many people do similar things. I have my info at home so I will have to get back to you.

Mr. Sam

gmsuv

I pulled off the driver side rail cover and it exposed agood ground where the fender attached to the body. I used that for ground. I then used a fuse tap at #15 for my ACC wire. I just now need a switched 12V. To activate Onstar I used fuse #7 (cigarette lighter) but that was hot all the time and that is a good battery drain that I don't need. I just want a tap that will shut off when the ignition is dead for my hot lead wire.

dadaroo

Fuse 15 in not hot in ACC. It is Hot in ON and Start. That is from the FSM


Fuse 11 (20 amp) is the ignition ON feed for Accessory Power in the I/P fuse box. It is not shared with anything else. You can downsize the fuse size to meet your need and wiring size.

gmsuv

Thank you

dadaroo

Are you sure you have ACC power from Fuse 15?

I just looked at the FSM again and found out that I/P Fuse 11 is also HOT in ACC which I did not know. So that fuse can serve both of your needs.

dadaroo

Good. I will look to see if Fuse 15 actually shows somewhere that it is also Hot in ACC. I had to search to find out Fuse 11 did that. The FSM is not consistent in that info.

dadaroo

If Fuse 22 was empty, how did your BCM work?

gmsuv

I do not know but I used #22, which was empty and #11 Acc.
It works so I will leave it that way. Here is a jpeg of my connections.

gmsuv

Just to confirm what others have said, this is from another post,

"Just read another post that says fuse 22 really doesn't have anything to do with the BCM. Rathere it is an unused switched source of 12 volts that others have used to power aftermarket add ons."

dadaroo

OK, I figured it out. Another GM misdirection. Fuse 22 shows as being for BCM Ignition 3 in all Owners Manuals and in all Factory Service Manuals from 97-04.

However, if you actually look at the BCM connector inputs it was only used from 97-99. BCM connector C1 pin B11.

gmsuv

Now I'm really confused.
Fuse #22 is hot in the (RUN) position but not in the ACC position and I want a fuse that is both hot in ACC and Run position.
What fuse can I tap so I don't run down the battery and still be able to use the phone in ACC.

dadaroo

I already told you what to use.

gmsuv

Switched Fuse#11?

dadaroo

Yes