2007 Trailer brake wiring under hood question

[rnh]

I just hooked up my prodigy and noticed no power, well I read over the descriptions on trailer wires in owners manual again and this time I picked up where it noted.  The power wire and elect brake wire fuses are installed, but the wires are not hooked up.  See dealer. 

I found the power ( red ) wire but couldn't find the dark blue wire.  Also has anyone here on board hooked them up and if so could you be so kind as to tell me where to hookem up?

Thanks

Richard

[sperry]

Richard, Did you get the "plug & Play" harness? It simply connects the Prodigy to the relay block connector.

The 30 Amp brake power fuse should be present in 02's and 03+
The 40 Amp coach power / stud #1 fuse isn't factory provided in either. But that one is not needed for the controller operation.

The wiring differs between the 02 and the later GM trucks. I didn't see what model year you have.

[AVid]

I'm guessing by his post that he has a 2007. If that's the case, the brake controllers are no longer plug-n-play. They must be hardwired under the dash, the necessary wires are there. No fuses need be installed, however, there are two wires taped up near the underhood center that must be attached to a stud in the fuse center.

AVid

[rnh]

sperry & AVid, thanks for reply. Just  rechecked my post and see I didn't put the year.  Dang, I must take a reading class.  Av is 2007. 

AVid, I saw the red/black wire, is the Dr blue wire close by too?  Also is the stud under the fuses?

Thanks
Rnh

[Steel]

Just got the Prodigy myself, but haven’t installed it yet.

Looks like you only have to hook up the rd/bk wire to the fuse box to power the Prodigy; the dk blue is power to the trailer brakes and is supplied by the controller.
 
Found this…may help: http://www.gm-trucks.com/forums/lofiversion/index.php?t53911.html

[rnh]

TIP: The red/black circuit 242 must be connected to Stud 1 (30 amp) of the UBEC. The wire is located between the left fender and the UBEC. Do not confuse this circuit with 742 (document 1706194) which is also red/black, and which is taped to the harness under the master cylinder. Circuit 742 is the 12 V supply to the 7 way trailer connector.

Steel, Pasted the above from your site you sent. Thanks.. But now I'm just a little confused and need some more help.  I found 1-red/black wire taped to harness under the master cylinder, Is this the one I should connect  I will go home tongiht after work and scout out the red/black  between left fender and UBEC. b.t.w. what is UBEC? 

Lost in Space (between my ears)
Rnh

[Steel]

TIP: The red/black circuit 242 must be connected to Stud 1 (30 amp) of the UBEC. The wire is located between the left fender and the UBEC. Do not confuse this circuit with 742 (document 1706194) which is also red/black, and which is taped to the harness under the master cylinder. Circuit 742 is the 12 V supply to the 7 way trailer connector.

Steel, Pasted the above from your site you sent. Thanks.. But now I'm just a little confused and need some more help.  I found 1-red/black wire taped to harness under the master cylinder, Is this the one I should connect  I will go home tongiht after work and scout out the red/black  between left fender and UBEC. b.t.w. what is UBEC? 

Lost in Space (between my ears)
Rnh

Don’t know, as I haven’t actually looked at mine yet, but if the info I linked to is correct, I’d have to say No…as stated, circuit 742 is the one under the master cylinder, not circuit 242 which appears to be the one that powers the Prodigy.

I’m guessing UBEC is a GM acronym for the Fuse Box.

Note to self: What a crock of sh!t all these loose wires are…bundled all over the place. 

[sperry]

UBEC: Underhood Bussed Electrical Center. 

Danged acronyms..

[Steel]

UBEC: Underhood Bussed Electrical Center. 

Danged acronyms..

Or... “Undocumented Bundled Electrical Connections”   

[Wazbro]

Don’t know, as I haven’t actually looked at mine yet, but if the info I linked to is correct, I’d have to say No…as stated, circuit 742 is the one under the master cylinder, not circuit 242 which appears to be the one that powers the Prodigy.

I’m guessing UBEC is a GM acronym for the Fuse Box.

Note to self: What a crock of sh!t all these loose wires are…bundled all over the place. 

Sounds like that 742 wire would have to be connected to the 40amp fuse for 12v supply to trailer though(whichever stud that is? ).

[Steel]

All right…I just took a look at this fuse box setup and as described, if you pop the fuse box cover, you can see the rd/bk power lead is taped to the harness in between the fuse box and the left fender.

However, at this point I have no idea how it hooks into the fuse box.

After you remove the cover, there are two gray handles at opposing ends that unlock and fold up toward each other. Upon doing this I expected the fuse panel to pull right up and out exposing the underside of the fuse block, but it doesn’t seem to want to cooperate.

So I quit for the time being, ‘cuz it’s like 100 degrees in the shade and I was sweating my arse off.

I’ll wait and see if anyone chimes in as to how the fuse block is removed.

[sperry]

`Need to get my hands on an 07's innards to snoop & tinker a bit with it. But not in 100° temps!


I see the topic's title depicts 2007 now..

[AVid]

`Need to get my hands on an 07's innards to snoop & tinker a bit with it. But not in 100° temps!


I see the topic's title depicts 2007 now..

I know what you mean. My neighbor has a new Tahoe but I'm not gonna look when its this hot. This heat is killing us northern folks!!

AVid

[rnh]

All right…I just took a look at this fuse box setup and as described, if you pop the fuse box cover, you can see the rd/bk power lead is taped to the harness in between the fuse box and the left fender.

However, at this point I have no idea how it hooks into the fuse box.

After you remove the cover, there are two gray handles at opposing ends that unlock and fold up toward each other. Upon doing this I expected the fuse panel to pull right up and out exposing the underside of the fuse block, but it doesn’t seem to want to cooperate.

So I quit for the time being, ‘cuz it’s like 100 degrees in the shade and I was sweating my arse off.

I’ll wait and see if anyone chimes in as to how the fuse block is removed.

Steel, just stepped out and poped hood in Sunny Fla weather, well a little overcast but anyway,  Standing at left fender, pull cover off UBEC.  Then Lift left handle and look to left side of UBEC in center you will see two stud's staring us right in the face.  I turned over the UBEC cover and see what look's like the silver stud is 30Amp fuse and Black stud is 40amp fuse.  Now I just need to run out and get a couple of nuts to secure wires.  Let me know if I'm correct.  OR if the Av doesn't burn up I'll know I got it.

Rnh

[rnh]

Al-rightly then!  Success.  Went to Advance Auto Parts and picked up the M8-1.25mm nuts and...Whamo  power to the prodigy.   I just left the 12v ( 742 ) off 40amp stud for time being.  I take it the 742 wire directs power into camper for temp lights while on road?  Anyway Thanks for all the help.   

On another note, which I can't get out of my head right now.  I fully understand dealerships need to turn a profit, but my Wife called 2 this morning to see if they could hook up wires for us.  Both asked if it was just the two wires under the hood and she said yes.  Both told her about 1/2 hour labor @ 35.00

If I were the owner of dealership or service manager, I would probably get more referrals if I did the two wire hookup for N/C as it only took me less then 5 minutes once I realized what was going on.

Thanks again to all that helped me here. 

Great site and So far we absolutely love the Gold Mist 4wd LT Av.  It sure is a major step up from our 02 Z71.

Richard

[Steel]

Ah yes, right you are…I overlooked the obvious. Just finished hooking my Prodigy up and all looks well.

Fuse 66 = Stud 2 (30A) circuit 242
Fuse 71 = Stud 1 (40A) circuit 742
 
Now the question is, what “is” circuit 742 (40A) for?

I’m thinking 12V supply to the trailer to charge an auxiliary “break-away” battery?

Any GM employees here have access to GM document 1706194? 

[sperry]

Yes, a constant supply but indirectly for that battery. As you are no doubt well-aware of it, others may not be. The breakaway batteries should have a separate charger since they are too small for the full current the coach power circuit could provide, and isolation is needed so that batt won't load down if it was directly connected to the Av..

It's primarily intended for coach power and a coach battery charge source for camping trailers.

And yup, if the coach battery is directly connected, it's hanging onto the Av's electrical. Only in this case, it's a big batt.

[Steel]

Thanks sperry, looks as if we have the ’07 Brake Controller installation solved.

It all appears to be a step backwards from the previous “plug and play” setup however. 

[02 Z71]

Glad to hear that you got this issue resolved. 

What a crock to have to hook this up on a truck that is meant to tow.  I know that it is a cost cutting measure, but how much is it really saving?  Are other manufactuers doing the same thing?  If not, it is really going to give GM's truck line a black eye.

When I got my Av originally I insisted that part of the deal was for the dealer to install a brake controller.  The dealer didn't acually do it, but gave me a coupon to have one installed for free at a local U-haul dealer.  Guess I will have to make sure I get that deal again if I buy another Chevy truck.

[jscott1000]

Just got my prodigy controller hooked up and it was a breeze thanks to you guys.  I never would have figured out that deal under the UBEC.  I would have paid to have it installed at the dealer, so you guys saved me some bucks!

I am only towing a 4500 pound car hauler so I probably don't need the electric brakes, but it helps. 

[Wazbro]

Just got my prodigy controller hooked up and it was a breeze thanks to you guys.  I never would have figured out that deal under the UBEC.  I would have paid to have it installed at the dealer, so you guys saved me some bucks!

I am only towing a 4500 pound car hauler so I probably don't need the electric brakes, but it helps. 

.

Well if you towed that trailer in New Jersey you would need trailer brakes because someone would definitely pull out in front of you. Besides in some states the law requires trailer brakes if the trailer is more then 2000 pounds and most other states require them if the trailer is more then 1/2 the weight of the tow vehicle (1/2 of 5500 pound AV =2750 pounds).

[USA1fan]

Surge brakes, maybe?  I don't have the space to keep a trailer so I rent from one on the many companies when we move and tow our second vehicle.  Even the car haulers have surge brakes (I'm guessing the 4500 pounds is loaded, btw?).

I'd love to be able to rent a trailer equipped to tie into the AVs brakes though.  Would be much smoother towing..

[jscott1000]

I don't know if trailer brakes are required here or not, but I wouldn't tow without them.  Eventually someone will cut me off. 

I paid big bucks to have the contoller installed on my old truck, at least the AV was pre-wired.

[Rukkus]

Hey all.I have a 2007 Avalanche and I am having trouble locating the power wire for the brake controller,it is in the harness somewhere but cannot locate it.Can anyone tell me where it is?.I have the accessory power hooked up (red/black) and it does give me lights in the trailer.I just need to know where the wire is located to hook up to the UHBEC.
Thanks

[SWFLA1]

rukkus -

you should have a harness (if it's like the 04's) that came with the truck.  I just put mine in and it was simple....  plug in the harness, the fuse, and connect the wires to the brake controller.... took 10 minutes.

I'm guessing the 07's don't come with the brake controller and you have to buy it separate....

Good Luck

[Steel]

Hey all.I have a 2007 Avalanche and I am having trouble locating the power wire for the brake controller,it is in the harness somewhere but cannot locate it.Can anyone tell me where it is?.I have the accessory power hooked up (red/black) and it does give me lights in the trailer.I just need to know where the wire is located to hook up to the UHBEC.
Thanks

The brake controller power lead is tucked in between the UBEC and the driver’s side inner fender well.

It’s taped to the harness that’s located there.

[doug494]

Dumb question here.

When I order a Prodigy, do I just need the unit or should I get a generic cable to go with it?

[Steel]

Dumb question here.

When I order a Prodigy, do I just need the unit or should I get a generic cable to go with it?

A generic cable is included with the Prodigy.

You just have to splice it to the factory “blunt-cut” wires under the dash, just above the e-brake pedal.

[SWFLA1]

It's my understanding that you have to hook up a couple of wires under the hood... I'm trying to do mine but don't understand how you tap into the under hood fuse box.

[Steel]

It's my understanding that you have to hook up a couple of wires under the hood.

Correct.

Did you read the first page of this thread?

The hook-up procedure is all there.

[SWFLA1]

yup...read it, what i don't understand is the actual procedure of attaching the wires to the under hood fuse box.  do you lift up those grey handles and yank the hole thing out?  does that have any affect on the car's electronics?  is there a place to insert the wires or will i need to get some kind of screws?

i'm normally only an idiot when it comes to women and electronics.... 

[Steel]

Steel, just stepped out and poped hood in Sunny Fla weather, well a little overcast but anyway,  Standing at left fender, pull cover off UBEC.  Then Lift left handle and look to left side of UBEC in center you will see two stud's staring us right in the face.  I turned over the UBEC cover and see what look's like the silver stud is 30Amp fuse and Black stud is 40amp fuse.  Now I just need to run out and get a couple of nuts to secure wires.  Let me know if I'm correct.  OR if the Av doesn't burn up I'll know I got it.

Rnh

[SWFLA1]

Steel - thanks for your patience and help.  Sometimes I just can't get my head wrapped around electronic stuff.  Anyway, i re-read the entire post and found the studs, now if i understand this correctly - all i need to hook up is the red/blk wire to the stud and it will power the breakaway batter and the electric brakes once i wire the brake controller in??

I guess from what I'm reading, the other wire underhood is for aux power to the trailer, which I won't need since I'm towing a utility trailer.

Thanks again...

[Steel]

If you don’t need auxiliary power to the trailer, you don’t need to hook up the rd/bk wire that is bundled under the master cylinder.

All you need to do is hook up the rd/bk wire that’s between the fuse box and left fender to the 30-amp stud in the fuse box and you’re done under the hood.

You should splice your connections under the dash to the controller before making the fuse box connection and then you’re all set.

[SWFLA1]

Thanks... sorry i'm thickheaded about this stuff....

[Steel]

Thanks... sorry i'm thickheaded about this stuff....

Fortunately, the risk of electrocution is minimal. 

No problem. 

[supraman23]

now that it is all solved for the 07,can somone please revise it all and sum it up in one reply with all the facts so nobody like myself makes a mistake.. :B:thanks.

[AVid]

The wire labeled "1" goes to the stud labeled "2".

The other wire taped near the brake booster goes to the other stud. Refer to the quote from Steel below....


AVid

If you don’t need auxiliary power to the trailer, you don’t need to hook up the rd/bk wire that is bundled under the master cylinder.

All you need to do is hook up the rd/bk wire that’s between the fuse box and left fender to the 30-amp stud in the fuse box and you’re done under the hood.

You should splice your connections under the dash to the controller before making the fuse box connection and then you’re all set.

[supraman23]

^^^thanks 4 the pics. they helped out alot. the only warning i must say to be aware of would be very careful when lifting out the fusebox. dont want any pins getting bent. i routed the aux power wire and the brake controller power wire in the fuse box as if it came that way. i was very careful putting it back in.. all went well thanks to the help of you all.

[ironflange]

Yeah, thanks for the pic, AVid. I'll have a go at hooking it up tomorrow. It's ridiculous that the 2007 doesn't use a handy harness like the older ones did. Of course, this is GM, and much of their reputation is built on craziness like this. And here I thought I was so smart, hanging on to the old harness when I traded the old Av in. I was pretty puzzled when I pulled that cover off under the dash to find no matching slot for the plug.

[USA1fan]

Yeah, thanks for the pic, AVid. I'll have a go at hooking it up tomorrow. It's ridiculous that the 2007 doesn't use a handy harness like the older ones did. Of course, this is GM, and much of their reputation is built on craziness like this. And here I thought I was so smart, hanging on to the old harness when I traded the old Av in. I was pretty puzzled when I pulled that cover off under the dash to find no matching slot for the plug.

I kept the harness from my Silverado and came to the same conclusion.  Maybe I shoulda cut the other end out of the truck before doing the trade!   

[ironflange]

I did it!



The under-hood business was a snap, thanks to the pic. Inside was a bit trickier, I had trouble finding the wires, but once found it was also easy. We went out to get the trailer tonite and it worked like a charm. If it hadn't been for you guys I'd be up the creek right now, but now I'm looking forward to the first trip of the season. Thanks everybody!

PS: The '07 Avy pulls noticeably better than the old '04, and not just power-wise. Handles better too. I'm a happy boy.

[danlwil]

The wire labeled "1" goes to the stud labeled "2".

The other wire taped near the brake booster goes to the other stud. Refer to the quote from Steel below....


AVid

Avid... I get the infamous red X box.... could you repost the pic of the fuse box for me please?

[hoffkm]

Thanks to all for your hard work in figuring this out.    After reading this topic hooking up my controller was a breeze.    Never would have figured this out on my own (and I'm an engineer by trade!).    Thank you GM for following the KISS principal, as usual, NOT!

[cainsw]

This is my first post on this board!

I just bought an 08 Avalaunche and I'm hooking up the trailer brakes and I've read the above post from start to finish but it was written for 07.  I assume it is the same but I'd like to know before I start.   I have found both red/black wires, the brake wire between the fender and beck, and the 12v under the master cyl.  My question is, do I hook the trailer wire to the small black stud #68  or the big silver stud #63? I'm assuming the trailer brake wire goes to the small black stud #68?

[AVid]

First      we're glad your here. The 2007 and 2008 are the same. Here is a link with pictures: GM Tech Link


AVid

[danlwil]

on my 07... the eyelets are different sizes...

don't remember the colors though

BTW    aboard

[gethighracewear]

Where did you guys mount your Brake controller in your 07/08 with a center console? I had it mounted at the bottom of the dash right under the ash tray on my 04.  But I am not sure where to put it on my 07.  Any pics or ideas would be greatly appriciated.

Gary

[Steel]

Where did you guys mount your Brake controller in your 07/08 with a center console? I had it mounted at the bottom of the dash right under the ash tray on my 04.  But I am not sure where to put it on my 07.  Any pics or ideas would be greatly appriciated.

Gary

I mounted my Prodigy under the dash above the emergency brake pedal, just to the left of the release lever. There’s a dash screw already there to fasten the brake controller bracket, so I didn’t even drill any holes.

It’s been working just fine there for a year and a half now. 

[Ace13]

OK.  Assuming I understand all this correctly....  Since I have a camper that I am towing, I will need to hook up the wire that is mounted under the master cylinder, correct?

[AVid]

OK.  Assuming I understand all this correctly....  Since I have a camper that I am towing, I will need to hook up the wire that is mounted under the master cylinder, correct?

Yes..that's the 12v feed to the trailer to charge the trailer battery.

[Apel]

I've been researching the brake controller wiring as I'm going to be picking up a travel trailer in a couple of weeks.  In my online digging, I ran across a youtube video of the brake controller wiring on the new 07+ Chevy platform trucks that don't come pre-wired. 

Here ya go: Brake Controller Installation

I found it helpful...hope y'all can use it too.

take care

[MS03 2500]

Thanks for the info Apel. 

[Apel]

One more bit of info to add....

The brake control 30 amp post takes a m8-1.25 nut
The 12v power 40 amp post takes a m6-1.00 nut

Enjoy!