thebrain

Difficulty wiring 7 way trailer hitch wiring 07 trailblazer

I have a 7 pin round tail/brake/blicker/anti brake reverse all I can manage to get working are the right/left brakelight/blicker can’t get the taillights on.

Here’s what I’ve connected all from trailer end plug.

pos1- ground black

pos7 trailer antireverse lockout. black

Pos3 tail light brown from yellow/green
pos5 green
pos2 yellow
I do have continuity on my wiring, and I’ve checked all the fuses under the seat all have continunity.
Not yet checked at the underhood fuse block there’s these associated w/ trailer
4 Back-Up-Trailer Lamps
32 Trailer

Additionally I have removed the radio circuit fuse the NAV unit took a dump and created a major drain 3.3amps on battery I could reinstall the fuse maybe the taillights go though the radio circuit. since radio unit is removed
Thanks for any helpful advice

edit: when I check the taillights I turn on the headlights, note the pass. side low beam circuit is faulty will check it's fuse and or replace bulb,
will a open low beam circuit effect the no trailer taillight issues?

I have tryed both methods in last images the only way I could brake light/blickers on was the yellow diagram. but still no taillights.



n

thebrain

51 views and zero advice **** you people

Richardman1992

iTrader: (5)

Did the trailer lights work fine when towing behind your van? Do you have power to the tail lights? The turn and brake functions use the same filament on most trailers. The tail light bulb filament if all located within one bulb isn't burned out, is it?

thebrain

Yes the tail lights worked fine w/ the van and it’s flat 4 pin coupler.

Now w/ the new lighter tow vehicle I added brakes to the boat trailer so I need a anti- reverse lockout for my surge actuater.

The new tow vehicle has a 7 pin coupler however no tail lights.

Not sure if I have power to the tail lights all I know is they won’t come on.
Don’t want to rip the interia apart for a single tail-light wire.

I'm using a LED for one light the other is just regular incandesent and the filament is intact.

Richardman1992

iTrader: (5)

Did the Saab come factory wired for the tow package or did you add it? Check for power there first, then at the wiring for the tail lights. If there is no power there, then the issue is within the truck itself. If there is power there and nothing at the tail light, you need to trace from there to the connection for the tow rig. My first suspicion would be when it was converted from flat 4 to round 7.

What do you mean by "inertia" when talking about ripping it apart?

thebrain

yes the tow wiring is from Saab

the wiring from the vehicle end attached at hitch then the wires run under body to middle of vehicle then under carpet to a couple anfewnall connecters in oder to fully trace this wire I would need to rip apart the back seat and carpeting.

w/ headlights on I will check for voltage at #4 on the vehicle end and report back

I think #7 is interferring w/ tails who knows what all other circuits on on the same circuit as the tails are
thanks

thebrain

I have no voltage on #4 w/ headlights on.

also checked the big red wire again no voltage.

I do have continuity on white to cars frame

1FastBrick

iTrader: (17)

Did you check these fuse for power? #10 instrument panel fuse box and #10 rear trunk?
Got the info from here.
Saab 9-3 (2007) ? fuse box diagram | Auto Genius

tippmann243

iTrader: (1)

the TBSS came factory with a 7 pin connector. you could look up the schematic for that and wire off it. should be damn close to a 9-7x

thebrain

excellent link however it's a 97x.Saab 9-7X (2007 ? 2008) ? fuse box diagram | Auto Genius

the V8 fuse block #24 is instrument panel. this fuse has continuity and the display displays inside the dash.

I confirm to have 3 circuits functioning 50,51 & 52.brake/blinker/hazard so it must be tail light, during my wiring the tail lights where only grounded w/ the white wire not individually to the trailer frame.

but the first thing I need is to powerup the pin#4

07 saab 97x trailer plug pin #4 wire