GMC Acadia Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
:cheers:
It's true, and no v92 fuse block needed. According to the electrical specialist at the dealer, the reason you can't splice into the existing taillight wiring is that the computer for the LED light system will sense a change in the resistance as soon as any corrosion in the splice starts and the system will fault. A way around it is to solder the connections. I dropped of the vehicle yesterday. and will see if everything works OK. He warned that I will not have a Brake controller nor backup lights available but all else will work. I'm towing a small ski boat so it's all I need. Also, he is somehow splicing into wiring harness added to rear fender wheel well for an adequate powersource for the trailer lights. Total estimate for parts and lobor $117 + tax.
I'll post the results when I pick up the vehicle today. If anything goes wrong, the dealer has to pay now!!! HOOOAH
 

·
Registered
Joined
·
428 Posts
Good luck with that. I was told and believe that the problem with splicing the tail light wiring is it creates a drop in voltage to the tail lights because the power is being split between the tail lights and the trailer lights. When I had this done I started having tail lights fail due to the drop in voltage. Soldering the connection will keep any corrosion happening but will not do anything about keeping the voltage from dropping. LED lights look good and are bright but they sure are funny about voltage.
 

·
Registered
Joined
·
1,703 Posts
I bet the dealer is getting power from the rear fender to power a device like this. http://www.etrailer.com/p-119176.htm
If he wires the trailer lights directly to the circuit, then for sure the resistance will change and the computer will detect it.
The corrosion may be true, but the biggest thing is that you need something like in the link above to electrically isolate the trailer so the computer cannot sense that it is there.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #4 ·
Yep it works great guys. Can't tell where he got the power from though. Wires come straight down from the back of rear floorboard and he gave me the 4-post plug just as I needed. I can give you the names of service rep at my dealer, and maybe your mechanic can talk to his...it's working just fine and only $ 126 tax included out the door. They told me they've just started doing it this way and they;d done about a dozen or so. Also got a call from another rep at the "Hitch House" in Plymouth MI, and he said an aftermarket was going to be available in just a couple of weeks and wanted to know if he should orderr me one. Too late... :cheers:
 

·
Registered
Joined
·
40 Posts
GAR said:
I bet the dealer is getting power from the rear fender to power a device like this. http://www.etrailer.com/p-119176.htm
If he wires the trailer lights directly to the circuit, then for sure the resistance will change and the computer will detect it.
The corrosion may be true, but the biggest thing is that you need something like in the link above to electrically isolate the trailer so the computer cannot sense that it is there.
I agree with you 100%. I just wish I could find the wires under the dash for the left and right turn signal so I can wire in my light converter that I bought today. It's a Hoppy 46365 the same idea as in GAR's link. I metered my tail lights (thinking I would install this converter at the back) but the rear tail lights only have a .7 volt differential (that is all an LED needs to work) so that isn't enough for the converter to see a change for switching. The front turn signals are regular bulbs that need 12 volts but I don't want to run wires up to them to hook into. These wires must run back under the dash, the only problem is where are they. I don't want to start probing wires needlessly I would like to know ruffly where they are and what color they are. I pulled out my fuse block to see if I could MOD it (taking it out took less than 10 mins and was easy) but I don't want to mess with it, I didn't want to open it up once I got it out in case I broke something inside it. So back it went, the only thing I gained from it was the knowledge of how to do it. So now I know if I have to go the way of the new fuse block it is something I can do myself in less than 10 minutes with only 2 screw drivers and a 1/2 wrench. But I am determined to do it without replacing it.

So if anyone knows what the left and right turn signal wires are under the dash let me know, :cheers:
 

·
Registered
Joined
·
1,703 Posts
If the converter is compatible with the Acadia, it should work with the wiring at the rear of the vehicle. From what I see in the schematic, the wire going to the rear lamp comes directly from the BCM. My guess is the voltage at the front of the car will be the same at the rear of the car. I would think that wiring at the rear, and not needing to run all the trailer wires the whole length of the car would be the best option. Just my opinion.
 

·
Registered
Joined
·
40 Posts
Well after think about it over night (while sleeping :sleepy:) I re-did some testing with a good old light probe, the digital meter just couldn't read the changes fast enough for the turn signals. When you disconnect them they go into a fast flashing to tell you there is a bulb missing. So it looks like I can just install this converter back by the light and pickup power somewhere and good to go. I will post later what wires I used.
 

·
Registered
Joined
·
40 Posts
OK it's done and working, man did I ever over think this. With all the post on here about getting having to get the dealer to install a new fuse block and add missing wiring harnesses, I thought this must be near impossible. Well it's not, it was rather easy. I would say if you can get a dealer to do it for $120 or so do it, this took some time because I didn't really know what I was looking for. My total cost for wiring this install was $62. I will start a new thread and go through my steps.
 
1 - 8 of 8 Posts
Top