Conversion to power doors - Wiring question

[Littlebeefy]

Hello all,

I'm trying to finish installing the power windows and locks on my 84 Bronco XLT, which originally had manual locks and windows. I secured the jumper wiring for the doors that goes behind the dash from an 85 Bronco, so I know I have the correct wire. I installed the hardware in the doors and connected the doors together and inserted the green connector into slot C1962 on the back of the fuse block.

I am now left with a blue/black wire with blue connector which I believe hooks into the tailgate window power switch (see pic below):



Research on previous posts seems to indicate that this plugs in behind the dash, but the wire is not very long and I can't find a connector that it can theoretically reach. On top of that, I'm an idiot when it comes to circuits, so I'm not at all sure what I am doing.

I currently have the dash completely removed (the plastic part, I mean), so I can access everything easily. Anyone mind giving me a quick lesson on how the tailgate circuit is supposed to wire in for the conversion to work properly?

Thanks!

[kramttocs]

Posting these here for quick reference:

[Gary Lewis]

This will probably have to be a several-post solution.  But here's the first one.

On Page 120 of the '85 EVTM (Documentation/Electrical/EVTM/1985 EVTM/Power Windows) we see the schematic below.  And note that the circuit has a light blue/black dot color.  Further, C1955 is shown on the next page as Blue with one connection and is in the LH cowl area.  And on Page 122 there's an illustration showing it about where it is in your pic.  So that matches and that connector appears to be C1955.

But you don't find the other half of C1955?  The wire that goes to splice S852 and branches to the RH front window control as well as to C1953?

[kramttocs]

Excuse my ignorance on Broncos but you have the rear window switch, correct?
If so can you follow it back to find the LB/BK wire that comes off of it? It appears the Bronco has a jumper/slice that should also have a plug for the blue connector.
In a pickup there is still the connector but it goes straight to the fuse block.

[Gary Lewis]

Here's the rest of that circuit.

And Scott is right - you should be able to follow back from the tailgate switch on the HVAC panel and see where it goes.

[Littlebeefy]

Super helpful info so far. Before I go around digging for wires and unplugging things, help me understand the 30,000 foot view on this thing.

The tailgate window was getting power before I added the power windows, so what purpose does connecting the switch to the power window wiring serve? If I am unplugging the tailgate switch from it's current connection in order to plug it into the window wiring that I just installed, what do I do with the connection that the tailgate switch was plugged into?

I have the very detailed wiring schematics but I'm just not very good at circuits, so treat me like I'm stupid (I won't take offense).

[kramttocs]

That S850 is a splice. So it's taking the power (+12v) from the fuse block and feeding both the rear window and the door windows. You shouldn't need to unhook anything from the rear window circuit but rather there should be a loose connector like you were looking for to hook into. Going from the switch (or from the fuse block side) gives us a solid point to reference.

Gary - I wonder if they had a separate wire that had or didn't have the splice/second connector depending on if the Bronco had power doors or not?

Chad - essentially what we need to know is if the LB/BK wire from the back of the fuse block goes straight to the rear window switch as a single, uninterrupted wire.

[Gary Lewis]

Let me try to explain how I see it and see if it makes any sense.

You had the power tailgate window, so you had the wiring shown on Page 123, which included a run of Circuit 400 to the Power Windows wiring on Page 120.  And, as shown on Page 120, that run from the tailgate wiring should include one side of C1955.

Now you have the power windows, and I think that provides the other side of C1955, and you just plug the two together.

[Gary Lewis]

kramttocs wrote

That S850 is a splice. So it's taking the power (+12v) from the fuse block and feeding both the rear window and the door windows. You shouldn't need to unhook anything from the rear window circuit but rather there should be a loose connector like you were looking for to hook into. Going from the switch (or from the fuse block side) gives us a solid point to reference.

Gary - I wonder if they had a separate wire that had or didn't have the splice/second connector depending on if the Bronco had power doors or not?

Chad - essentially what we need to know is if the LB/BK wire from the back of the fuse block goes straight to the rear window switch as a single, uninterrupted wire.

I agree with the question about the single, uninterrupted wire.

But on the question of a separate wire that didn't have the splice, that's hard to figure out from the MPC.  Let's await an answer on the other question?

[kramttocs]

Sounds good. I'll sit back and watch so we aren't talking over each other (where's that popcorn emoticon when you need it ).

I should probably rephrase 'separate wire' to avoid anyone else misreading that. To better say it: I wonder if they had two versions of the LB/BK circuit depending upon the Bronco options.

[Gary Lewis]

Please don't sit back.  I'm trying to figure out why my clutch switch doesn't work.  (The starter's relay pulls in w/a fuse in the connector, but not connected to the switch.)  So I'm in and out, painfully.

[ArdWrknTrk]

Gary, reset the switch by sliding the plastic block down the rod.
It will then self adjust the first time you depress the clutch.

[Gary Lewis]

Jim - Thanks.  I've done exactly that, as explained on Big Blue's thread.  But 'til now I didn't realize how that switch adjusts itself.

[Littlebeefy]

I have returned after further investigation and brought photos. First off, use this diagram for reference:



Here is a picture of the back of my fuse block. You can see the green connector in C1962 that I put in when I installed the power door wiring. Also, you can see a thick light blue wire with black dots (covered in brown dirt) connected at C1960. It's hard to tell it's a connection because the connector is the same color plastic as the fuse block. Seems like this is the tailgate window power source, at lease it was when my truck left the factory, right?



Also, at the top left of the dash there is a bundle of wires out of which comes this little blue connector with blue and black wiring:



...which is obviously the right connector for the blue wire that comes from the power door jumper wiring:



So, assuming the two blue connectors get plugged into together, does something else need to be unplugged somewhere? I feel like the tailgate had to be getting power from somewhere before I put in the power doors, so don't I need to disconnect that? What is te purpose of the wire that is plugged into C1960?

[kramttocs]

Great!
Nope, nothing needs unplugged. The 'new' wire is pulling power from the connector you just found. So it's not that you are providing two sources to the tailgate switch if that's what you are thinking. It's one source from the fuse block feeding both the tailgate window AND the door windows.

[Gary Lewis]

kramttocs wrote

Great!
Nope, nothing needs unplugged. The 'new' wire is pulling power from the connector you just found. So it's not that you are providing two sources to the tailgate switch if that's what you are thinking. It's one source from the fuse block feeding both the tailgate window AND the door windows.

Amen!

[Littlebeefy]

Well when you put it that way, it seems pretty obvious. I had been operating under the false assumption that the wire I plugged into the back of the fuse block at connection C1962 was power for the doors. In fact, it is just power for the door locks. As you pointed out, power for the windows is spliced off the same wire that powers the tailgate window.

Thank you for enlightening me. Maybe now I can finally get these windows to work...

[Gary Lewis]

Scott's the man!  

[Littlebeefy]

So after I hooked up the wiring as suggested (thanks all), the windows still didn't work. I knew two things with certainty: the motors were new and the wiring was hooked up correctly. I really wracked my brain to explain what was going on. Most of the problems (electrical or otherwise) that I have had with my 928 are because of issues with grounds. I figured I'd start with that and checked the contact with the ground connection in the driver door. That contact was clean, but then it occurred to me that the only way that the ground in the door can work is if the contact between door and the chassis was not insulated. Ultimately, that was the problem. New paint on the door jams and door hinges was acting as an insulator, so I had to run a separate ground wire to the door.

Lesson learned: Paint is a very effective insulator. Always check continuity to ground first!

[Gary Lewis]

That's a really good lesson to learn, and to communicate.  Thanks for passing it on.  And I'm glad you got it sorted.