jwbeck17

I need some guidance on installing a replacement seat back. My original seat back had some pretty bad bolster tears, so I was able to get a replacement seat back, which I have color matched. The issue I am having is that the new seat back has different wiring connectors than the original.

The seats are the the standard seats for the '89, with two side adjustment discs and no heating or lumbar.

The wire harnes of the original seat back had two connectors that went to the under seat wiring connector panel, a female molex connector and another multi wire connector.

The replacement seat only has a single male molex connector.

Under the seat is a male molex connector along with the multi pin connector.

Any suggestions on how to install? Will share pics.

Thanks,

Jason

jwbeck17

Original seat back connectors (note that I was incorrect in the above that it had a molex male connector. It has a female one.) Also the under seat wire connectors are 4&8 with the connector cut off 5.

jwbeck17

Replacement seat back has only s male molex connector

jwbeck17

Lastly, the seat base only has a male molex connector along with the multi-pin connector.

jwbeck17

My hunch is that it doesn't need to connect to anything. I do not have lumbar support or heat in those seats, so the seat back itself does not nead any power, as I believe the base does the fore and aft adjustment, correct?

Wisconsin Joe

Note: I have an 85 with 8 way comfort seats. There are differences, but I think I see what's going on.

Forward/back & up down are controlled from the base. You can see the 3 motors in the last pic (near the top, two round motor cans middle & right, transmission going to cables on the left)

The 2 pin that goes from the base into the seat back controls the recline. The motor is built into the seat back, up near the headrest.
You are either going to have to find a female connector that matches (off the old seatback, perhaps?) or a complete connector.
Keep in mind that the switch simply provides current, going one way reclines back, the other way leans it up. You will have to bench test it to make sure that you wire it right (or chance it and possibly live with the switch being backwards).

I don't have the other connector, I'm going to guess that's for heat & lumbar.
I'm pretty sure you know that the 14 pin on the right of the pic is the connector to the car harness (but someone else looking at the thread might not, so I'm going to note it).

jwbeck17

Great feedback, and thanks. I was trying to compare the wiring to the wiring diagram I have for the '89' but I am not an expert in wiring diagrams, and this one is really challenging to read for me.

I have to go back and check, but in addition to the 14-pin female connector in the car, I beleive there was also a separate two pin connector in there as well that was connected (passenger side does not have this). I also remember that a t least one connector was not connected in the original.

It may be just easier for me to look and the recline switch and follow the wires to the right connector.

And there is a female two-pin connector for the old seat back that I can pull and reconnect if needed.

Will let you know what I find out, but if anyone has any better knowledge of where these connectors are in the wiring diagram, Id greatly appreciate it!

Gary Knox

Jason,

I believe the seat bottom has a connector that also accounts for the seat belt warning light, as well as a connector to the rear backrest which contains the 'rake' adjustment for the backrest (the 'rake' electric motor is right behind your head!).

You may need to do a bit of playing with the connection between the rake motor and the seat bottom (after you've installed the backrest onto the seat bottom frame) to get the front arrow of the rear switch to bring the seatback forward, and vice versa.

jwbeck17

I believe the two-pin molex on the seat bottom connects to the female molex in the car. However, it lines directly into the seat belt lock, so I think it may only be for the seat belt sensor. That means that that the seat back got power through the multi-connector some how, as that was connected to seat wire control panel at connectors 4 and 8. (The female molex pin on the old seat back was not connected as well as The second molex next to the multi-connector.)

So my plan of attack is to find out which connector adjusted the back - 4 or 8. Then I will have to figure out the wires from that connector, and somehow wire it to the new seat back.

Alan

Looks like you have a memory seat and you are attaching a non-memory seat back.

Alan

James Bailey

As usual Alan is correct ! Memory seats are wired so the brain can remember the three different locations for each setting and readjust to them as desired.

jwbeck17

Thanks for your help, guys! I wasn't aware that the seat back memory unit was in the seat back itself. The seat memory is not that big a deal to me, as the memory system has worked spotty at best. The leather is in excellent shape on this non-memory seat back.

Now I guess the question is, is there a way to connect the new seat back to the memory seat base so that I can adjust the seat back? If there is, is there a way to do so without doing open-heart surgery on the wiring? Changing connectors is one thing, but I want to make sure that I am not destroying both the seat back and bottom.

Any suggestions on how to handle?

Alan

No - nothing you can do with this seat back (except use just the cover maybe?). The memory unit is under the seat bottom - however memory seats have both a motor and a position feedback potentiometer on every motor that both need to get wired back to the memory controller.

Your new seat back has no feedback potentiometer so the seat recline position can never be known. Without the potentiometer the memory recall may do strange things - like recline the seat all the way or try to fold you in half. However it only continues the recall operation for as long as you hold the button so it really isn't that dangerous - but it may well effectively cancel out the memory usefulness of all the other position motors.

Alan

jwbeck17

Thanks for the detail, Alan. So my options now are:

- keep with the original seat back and do what I can to fix the leather (it is cut up pretty bad though)

- recover the original seat back with the cover from the new one. (I didn't think about this one, Alan. Is this recovering easy to do or would I need a pro to do it?)

- use the new seat back and connect the wires so that the seat back adjusts...and not use the memory system. (I'm ok with this solution as well, but my pref would be to have the memory functionality working at some point)

I like the recovering idea if that is not too problematic. I currently have my track seat in the drivers position so I do have something to sit on.

Any recommendations on best steps?

Alan

You can swap the cover - but you need Paul or Rob (or similar) to explain how and how difficult.

It clearly is doable - I'd target that route if I were doing this...

Alan