cluosborne

For the past month or so, I've been doing a lot of upgrades; among them installing an alarm system into my 88 GTU. This included gutting the entire interior and reworking the front and rear harnesses; both to reroute/eliminate the factory anti-theft system and integrate the new alarm.

One of these modifications included using a window automation controller to remotely open and close the sunroof.

During my tear-down and subsequent reworking, I found that the sunroof motor got its power--ignition switched +12v--from a single 16-awg wire that ran down along the driver side A-pillar into the interior fuse box. The control switches basically switched ground/lead--lead/ground depending on which button was pushed. For a motor that is pushing and pulling a sunroof panel back and forth, this can put considerable strain on this small lead wire and switch gear.

When I reworked the sunroof wiring for the automation module, I eliminated the ground wires from the control switches and only used the +12V power lead as a control trigger only. This had the benefit (for me at least) of simplifying the wires and eliminating the two relays and vent switch (the module handles venting and is smart enough to detect obstructions and limits).

In other words, when you apply +12V, it triggers the automation module to open or close the sunroof. The motor is now directly connected to the automation module, which use larger 14-gauge wire, which is powered from a dedicated 30AMP fuse-protected circuit, that is fed directly from the engine compartment using 4-awg cable (the same feed is also used to power the alarm, a pair of stereo amps, power door locks, power hatch release, relays, two high-output 12V sockets, and a halogen work lamp).

The result is that the sunroof now opens and closes consistently, and the motor doesn't sound stressed anymore. The window automation module also adds one-touch open and close so you don't have to press and hold the button.

If you want to perform this modification yourself, you don't need to buy a window automation module; you can use a pair of 12V DPST relays connected to a dedicated fuse-protected circuit. If you go the relay route, bear in mind that you won't have one-touch open and close and you may want to retain the vent function (the relays, etc). The factory diagram of the sunroof wiring is easy to figure out.

jgrts20

A write-up with Pics and diagrams would be nice, sounds pretty cool!! I might be interested in doing that. Create a sticky

My5ABaby

iTrader: (7)

I would of just cleaned/lubricated the rails personally... but interesting info.

cluosborne

The first place to start is page 74 of the Wiring Diagram section of the Factory Service Manual PDF. Or page 50-84 if you have the hard copy of the FSM.

Unfortunately, I took few pictures, and my documenting skills leave something to be desired. However, off the top of my head, below is a better explanation of how to do it. It's not a step-by-step how-to, but anyone who knows the car's electrical system and can follow diagrams should get by. This is assuming you're using an automation module like the Clifford SmartWindows4 (which I have, has one-touch open and close, requires a compatible alarm) or the DEI 530T (adds one-touch open and close). The DEI 529T should work too, but it doesn't have the one-touch operation.

Tools needed:
soldering iron
precision screw driver set (slotted)
philps screw drivers
crimping tool (optional, but use a good one)
heat gun (optional)

Materials needed:
rosin core solder
desoldering braid
electrical tape or heat shrink tubing
14-awg stranded copper hookup wire
30AMP fuse and fuse holder - connected directly to the battery in the engine compartment
window automation module

Rather than go through step-by-step instructions, I'm going to give you a (hopefully) clearer picture on how I managed it with the automation module by giving you a diagram and picture of the modified switch.

Basically, on the sunroof control switches, you're only going send +12V to trigger open and close, so you remove the ground and lead wires and resolder the switches to only provide +12V when a button is pressed.

On the wiring harness, you remove all but three wires; green (+12V ign switched), yellow and yellow/red, the latter two which will run from the switches to the window automation module. To minimize any voltage drops (depending on how long the wire runs are), I ran the new larger wires as close to the motor harness plug as I could. You remove all but the yellow and yellow red wires from the harness-side of the plug (leave the motor side alone). Splice (solder and use heat shrink) the larger 14-gauge wires onto the yellow and yellow/red wires and plug in the motor.

Now, with the ignition on (since you're now using the original +12V ign sw. as a trigger lead), test by pressing the open and close buttons.

Now if you're going to use a pair of relays, you can use the same diagram to accomplish what you want, but you lose the factory vent function and you won't have one-touch operation; however, i think a pulse timer--one on each relay coil-- should work.

cluosborne

I have done that and highly recommend that anyone with a sticking sunroof clean and re-lube it first as increasing current to the motor by itself won't help.

Correction:
Actually, I didn't completely research that part of the electrical system. The sunroof has a 15-amp fuse-protected circuit, and assuming the wire run (from fuse box to motor) is around 10 feet, it's enough to carry the load. I think what my rewiring addressed was that the switches were a weak link; they have to carry a minimum of 15 amps of current.

So you don't need a 30-AMP fuse as 15-amps should suffice for circuit protection for the sunroof motor. However, moving the electrical load off the control switches onto a a pair of relays should improve the amount of current that gets to the motor.