There are a number of threads on adding a switch to control the rear windows on the Convertible.
Here's a diagram I made to clarify things in my simple mind. Thought it might be helpful to some.

My problem is how to run a wire from the relays in the trunk / boot to the center console.
Does anyone have any tips on an easy way to do that?

 

There are wires in place from the convertible top switch to the convertible top module by the relays, run new wires alongside. Why do you want to do this, never have understood what the advantage is?

 

Some like the idea of being able to just open them with the top up for some fresh air, but not the "full window down" effect, and some like being able to leave them up when the top is down for a little less buffetting. Yet others do it due to them stopping working properly. I did it because mine stopped working for the most part and they would get stuck. With the switches, you can trigger the motors several times and sometimes it jars the gearbox and gets it moving sometimes.

 

I just want to be able to have the top up with all 4 windows down.
Have you ever had a car that you couldn't control all the windows manually?
I also will be disabling the hand brake interlock to lower the top and will be adding a switch to manually control the antenna.
Guess I'm just a control freak! ;-))

 

You can have all windows down with the top up on the standard car. Read your instruction manual? I disabled the handbrake and neutral interlocks on mine and the standard window design works fine.

 

I think that is called a bodge.

 

I don't have an "Instruction Manual" but I did read in my Drivers Handbook that you can lower the rear windows via the switch if you keep the hood latched. I had heard others say this but did not realize it was an approved method. It just seemed to me to be putting stress on the components. So, you are correct.
However, IMO you could use a bit of an attitude check and should think about the tone of your replies.
Just sayin' . . . . Over and out - I'm done.

 

Perhaps it is, but it’s his car to “bodge”. Unless he’s sneaking into your XJS at night and modifying while you sleep, there’s no need to be so unpleasant.

 

I ran my wires over the right wheel arch, I cant remember exactly how l wired them but l fitted a small push to contact switch just under the armrest overhang and it bypasses the handbrake and gear earth control allowing the rear windows to work off of the 2 window switches while driving using a second cut down relay board from a scrap car to work it..






Most properly not the fastest way or best way to do it but it works.

 

Thanks for the reply - Now I have to figure out how to wire that switch.

 

The switch takes a ground to the relay panel and overrides the ground from the hand brake and the gear selector it also sends the switches to the other bank of relays.

 

Thanks again.

Unfortunately, my wifes Mini just checked out with Cyl. 2 misfires. Swapped the coil packs = no change. Have to get out the serious toolbox.

 

So, please help me. I am terrible with electrics...

Is it like this...?

- Find the negative/ground wire at each of the up and down relays (pin 85 wire). The pole that grounds and engages the relay...?

Connect an added grounding wire to all 4 of these individual pins (85). The relay grounds. Then, tie these 2 wires (combined and spliced) into ONE going to the switch for the UP direction on the switch...?


- and similarly the same for the 2 wires (combined and spliced) into one going to the switch for the UP direction on the switch...?

What kind of switch...? A three wire switch where the third (I guess middle wire) is earthed?

Is that the jist of it?

And (if that description is correct) the window will work as it's designed for normal top operation as well, as long as the added switch is in the OFF/neutral position...?

Ok! No laughing...
Help a Brother out here.

 

Yes, you are correct, sorry, I should have been nice and just advised him to buy a fire extinguisher so at least he is prepared for the inevitable when the motor eventually burns out.

 

Don't make it too complicated. Simply put, grounding pin 85 energizes the relay sending 12v to the motor.
You can do that in many different ways.
My idea is to wire it to the existing front window switch ground wire. That way one switch will control both the front and qtr. windows will raise or lower at the same time. I can't think of any time I would want the front windows open and the back windows closed so this seems to me to be the easiest way to do it.

 

Hey Man, Thanks...
Complicated is exactly what I hope to avoid.
A step by step in this kind of situation helps me.

So, I thought it was a switch to ground kinda set up....?

Where the OE roof switch completes the circuit to ground on the control/engage side of the relay(s) powering the windows (and roof)...on button push... In that, I thought a second switch would be needed (I personally don't want one switch's to ALWAYS roll the quarter windows) to provide another controled ground path to ALL 4 85 pins. 2 (combined into one) for up, 2 (combined into 1) for down - wired to a switch... A switch that will provide a path to ground when engaged...

​​​​​​I'm going to go back and re-look the diagram in the thread. or maybe bust out the ED for the 1990... I'm not going to do this today or anything, but since folks are talking about it I am going to take the opportunity with the hope of getting my head around the idea now...

 

The diagram is a simplified version of the one in the ED manual.
Here's another version with the diagram of the front window switch.
I'm learning a new program (Affinity Designer) so I'm using these diagrams to practice on.

 

Great diagram. Thank you!

So, if I connect the BLUE and GREEN wires (see mac's diagram) to a switch like this,,, to the outer left and right pins on this switch, and ground the center pin, I should be able to control the up and down of the 1/4 windows,,, correct?

Anyone have an answer to this ^^^^^?

 

Maybe it is, and I'd love to just get new motors and do it "right", but seeing as how the motors have been nla for at least a couple of years and it's kind of a crap shoot to just buy a bunch of motors and "see" which ones might work. I did see that the one Mercedes window motor is supposed to work, but last I saw was a minimum of $400 each, I would rather not blow that much just to see if they'll work. By all means, if you know of a motor that would be plug and play for a reasonable price, I'll gladly buy them and put them in my car just for you, just to give you that warm fuzzy feeling inside lol. Otherwise, I look forward to seeing your post in a few years when yours start acting up. 😁😁

 

lmaoo, but you bodging up your car is perfectly fine, huh?