Quick wiring harness question

[SeaVee]

My girl is back from paint. Gonna start putting her back together. I have a new Painless harness. What’s the best time to rewire by that I mean should I rewire before I put the heater box and pedals in or should I put everything in and then rewire?

 

[AzBroncoGuy]

I recently did the same thing. I see that the dash is still in your bronco. Mine was out and it made life a whole lot easier. As you have already found out, just about everything hooks to the dash. It was real easy to install all of the switches and lights in the dash on the bench. Routing and securing the harness behind the dash is easily done as well. All of the heater controls were installed as well. I did put the heater box in first and then installed the dash and wiring harness as an assembly. If you can't or don't want to remove the dash then I'd leave everything out, you will need all the room that you can get!
Good Luck

 

[DirtDonk]

Another advantage of at least starting the process now, is that you can better see where things go, an also if you try, can envision where things should go if different from where they have been.
You might decide to make changes, or you might keep many of the factory wiring locations intact.
If you’re making other changes like fancy stereos, lots of lights, or other things, now is the time to decide where to put those wires. Under the hood, maybe you want to route things differently or maybe even hide them.

So at least lay the harness out a couple of times in a couple of different ways, and start the process in your mind.
And no matter what you do, and no matter how complete the Painless harness is, don’t throw away your old wiring yet!

 

[SeaVee]

Thanks guys- I can remove the dash pretty easily, so I’ll go that route. No add on’s like lights, stereo. Basically trying to make it as stock as possible.

 

[bigmuddy]

When I did my first harness, I pulled the dash out as far as I could get it, in the bronco and with a buddies help laid the harness over the dash and started connecting from there, once it was complete we did a test on the separate parts of the harness then reinstalled. Then we started running the wire out to the front and rear. Again, not optimum but it worked. That was with a Centech.

More recently using a Painless harness we installed on the bench and tested there (found issues with the harness) Fixed said issue then installed the dash.

Personally, I would leave the heater box out until you have the harness installed. Its really not bad to install with the dash in place IMO.

 

[Torkman66]

Just did this. Agree that it is best to have dash out and install everything on it first. The bundles that go through left, center and right firewall are easy. The one on passenger side is up in corner but as long as the air tube is not installed, easy to get to.
One thing I strongly suggest is to attach the heater cables at the box BEFORE dash goes back in. You can then run the dash side in after installed. The cables are not easy to attach once dash is in.
I also found that the drivers side wire bundle that goes up to the headlight was barely long enough to reach. May of had something to do with how I ran the wire loom on back of dash. Two extra feet on passenger side. However the harness has to pretty much go in one spot on back of dash in order for the switches to all line up. Anyway, might want to do a bit of measuring the wire length before installing dash back in just in case you need to pull more length out drivers side.

Also, this is time to run grounds. Painless assumes good grounds and most Broncos are poorly grounded. I “over-ground” when rebuilding. I run the battery ground to one of the starter mounting bolts. That gets the hot and ground within 4” of each other for starting. That also grounds the engine and trans. I also run a ground from that bolt up and into cab behind dash. Use that to attach all your ground wires to. Another up to back of alternator. I also have a grounding strap from engine to frame. I have short 6 gauge wire in back from frame to body. Also a ground that attaches to back side of grill. Yep, lots of ground!

 

[SeaVee]

That’s some good info! Thanks. Went and took another quick look. May just leave dash attached. There is absolutely nothing mounted anywhere near the dash so it shouldn’t be too bad.

 

[Torkman66]

If you want to leave it attached, just remove the top mounting bolts and top bolts from the kick panel L bracket. The dash then rotates 90° ad makes it just like on a bench other than you are sitting inside bronco when doing the wiring.

 

[Steve83]

Did you read the Painless instructions?

 

[SeaVee]

Not yet, LOL