Brake Controller Installation Parts Needed for A 1997 GMC Yukon with a Prodigy P3 Brake Controller

Question:

1997 GMC Yukon with trailer towing package and your part 90195. A couple of installation issues I could use some guidance with. At rear of vehicle I have found all trailer wires and have successfully hooked up ground, left and right brake, backup, and tail lights. Three wires have me confused. A heavy guage orange wire that is not on the shop manual wiring diagram. A heavy guage blue wire indicated as Auxiliary Lead on the shop manual diagram. A light guage white wire with a tag Brake SW but not shown on the wiring diagram. Ive assumed the blue is the 12v battery lead and the white is the brake controller lead for the 7 pin harness. Not sure these are good assumptions. Any thoughts? My second issue is that I cant find the other end of any of the three wires discussed above. The shop manual indicates the blue is taped to body near fuse block. I cant seem to locate the blue at that location. I havent found them under the hood kind of expected the blue and orange to be at the studs on the fuse relay center. Any thoughts as to where they might really be located? Thank you

asked by: Scott

Expert Reply:

When wiring up a 1997 GMC Yukon it is recommended you install a Brake Controller 7 & 4 Way Installation Kit # ETBC7 as the wiring that you have found is often difficult to access and you will need to run additional wiring regardless.

The # ETBC7 kit will eliminate any guess work and will come with everything needed to wire up your Tekonsha P-3 Brake Controller # 90195. I attached installation instructions for the # ETBC7 as well as an installation video for you to check out.

Most likely the blue wire you have found is the brake output wire circuit that takes the brake output signal and the orange wire is the auxiliary power source. The white wire sounds like it is a brake switch wire for trailers with reverse lights or a reverse lockout for a surge brake coupler.

However, where those wires terminate under the hood of your vehicle is inconsistent and difficult to find. That is why the # ETBC7 is recommended for your vehicle.