Locker fuse or relay help

[rascole]

I just installed a new front CI diff with a locker. I would like to wire the locker to engage when the rear is engaged. I can't seem to find the fuse or relay for the rear locker to splice into. I have searched several PDFs and diagrams with no luck, the fuse panel doesn't even show a location. Is there even a fuse for the sucker? Long term I plan on installing a sPod with a dedicated switch, I just wanted to get it up and running now.

 

[alrock]

Are you looking to have it automatically engage when the rear is engaged? That would be a bad idea, you often don't want it engaged even if the rear is on. Don't forget you basically lose steering with the front locker on, and you can use the rear locker for longish stretches of rocks where steering is needed. It's really not a challenge to run a new switch and temporarily mount somewhere.

 

[4speedfunk]

The factory set-up for 09-10 AP models (with F&R lockers), is such that the front locker is wired downstream of the rear. So while the front has its own switch...it only works while the rear locker is engaged. This allows you to operate the front locker separately but, only as a backup traction aid to the rear locker. As soon as you cancel the rear locker (or take the t-case out of 4-LO), the the front locker will also be cancelled. Even though GM gives you independent switches, the lockers are not truly independent. For this reason most guys (including me) adding a front locker to a 06-08 H3, choose to wire it to a totally separate circuit. In fact, some 09-10 owners have expressed an interest in re-wiring the GM rig so the front can be activated without activating the rear.

There is a secondary interest in re-wiring the locker(s) so they work in all t-case modes...and a few guys have done that mod. This allows you to do high speed (hi rpm) runs in deep sand while being locked.

IMO...just install a switch and hook it up.

 

[f5moab]

If you only want the front to engage when the rear engages, tap into the rear locker circuit from the TCCM. This way the front can only engage when the rear has been engaged by the TCCM. Install a relay trigger circuit into the L-green wire from the TCCM to the locker, with a switch. Then run a hot fused wire (just attach the wire with a fuse to the B+ of the battery) to the front locker. That way there is no power to the front unless the rear has been turned on by the computer. Nice part of this is you cannot engage the front locker by accident when doing 70 mph on an interstate.:emb: (I always remember the phrase, "hold my beer and watch this."):giggle:

 

[rascole]

Thanks, my intention was to keep the safety logic of the rear diff while having and independent switch. I was still planning to add a dedicated switch, hate the idea of someone accidentally flipping the switch on the run.