Blowing Fuse

[needcarhelp]

Have a 2007 Yukon. Keep blowing fuse 34 (2A). Have put multiple fuses in and it keeps blowing when turning the car to the On position. What would cause this?

 

[Fless]

Here's the wiring diagram for that circuit on a 2007 Yukon 5.3L; if yours is different use the links at the top of the page to get to the similar diagram for yours (but they're likely the same):

Power Distribution Diagram 13 — 2007 GMC Yukon 2WD V8-5.3L Service Manual | Operation CHARM

Detailed repair manual for the 2007 GMC Yukon 2WD V8-5.3L.

charm.li

DLIS: Discrete Logic Ignition Switch

You could try disconnecting the ignition switch feed, and/or the theft deterrent module feed, to see if one of those is blowing the fuse. Or it could be a shorted wire along the power distribution path.

 

[needcarhelp]

Here's the wiring diagram for that circuit on a 2007 Yukon 5.3L; if yours is different use the links at the top of the page to get to the similar diagram for yours (but they're likely the same):

Power Distribution Diagram 13 — 2007 GMC Yukon 2WD V8-5.3L Service Manual | Operation CHARM

Detailed repair manual for the 2007 GMC Yukon 2WD V8-5.3L.

charm.li

DLIS: Discrete Logic Ignition Switch

You could try disconnecting the ignition switch feed, and/or the theft deterrent module feed, to see if one of those is blowing the fuse. Or it could be a shorted wire along the power distribution path.

The car is in anti-theft lock mode. In an attempt to do the 30-minute relearn process, the fuse blows every time the key is turned over.

Do struggle to read the diagram, but from what I can gather, it is either the ignition switch, anti-theft module, or bcm. Correct?

The same thing happen about three weeks ago. Was able to unplug the battery, replace the fuse, and do the 30-minute relearn process. Everything seemed to work.

 

[mikez71]

It looks like that brown wire (circuit 4) that also connects to a yellow wire to the theft module is wakeup signal.
Might unplug terminal 3 on the ignition, and if the fuse still blows it's your ignition switch.

If not.. plug 3 back in and...

You can try disconnecting the theft module (might be remote control door lock receiver or RCDLR) and see if fuse still blows.
You can unplug J4-10 from BCM to rule out anything else down the accessory WakeUp line (notice the passthrough in diagram below).
If it still blows with both theft module and j4-19 unplugged, then I think it's the BCM (assuming you checked the ignition switch first).

 

[needcarhelp]

It looks like that brown wire (circuit 4) that also connects to a yellow wire to the theft module is wakeup signal.
Might unplug terminal 3 on the ignition, and if the fuse still blows it's your ignition switch.

If not.. plug 3 back in and...

You can try disconnecting the theft module (might be remote control door lock receiver or RCDLR) and see if fuse still blows.
You can unplug J4-10 from BCM to rule out anything else down the accessory WakeUp line (notice the passthrough in diagram below).
If it still blows with both theft module and j4-19 unplugged, then I think it's the BCM (assuming you checked the ignition switch first).

View attachment 467990

Removed the wires to the ignition switch and anti-theft module. As soon as I plugged in the ignition switch and turned the car over, fuse 34 blew.

 

[needcarhelp]

Here's the wiring diagram for that circuit on a 2007 Yukon 5.3L; if yours is different use the links at the top of the page to get to the similar diagram for yours (but they're likely the same):

Power Distribution Diagram 13 — 2007 GMC Yukon 2WD V8-5.3L Service Manual | Operation CHARM

Detailed repair manual for the 2007 GMC Yukon 2WD V8-5.3L.

charm.li

DLIS: Discrete Logic Ignition Switch

You could try disconnecting the ignition switch feed, and/or the theft deterrent module feed, to see if one of those is blowing the fuse. Or it could be a shorted wire along the power distribution path.

Removed the wires to the ignition switch and anti-theft module. As soon as I plugged in the ignition switch and turned the car over, fuse 34 blew.

 

[mikez71]

Removed the wires to the ignition switch and anti-theft module. As soon as I plugged in the ignition switch and turned the car over, fuse 34 blew.

assuming you meant plugging in ignition switch without pin 3. If so, pretty confident that is your culprit.