96 Jimmy Hatch Problem

[Rhoneb]

The dash button for unlocking the hatch window does not work, nor does the button on the key chain. There is no sound when either of the buttons are pushed. It is also not possible to unlock the rear hatch using the key. Are these two problems related? The first thing I suspected was a bad fuse, but I have not had any luck finding any that are blown. Any suggestions?

[old_master]

Quite possibly the actuator in the tailgate is faulty, or there is an open circuit going to the actuator. The only way to tell for sure is to somwhow get the trim panel off and check the circuits at the actuator.

[Rhoneb]

Originally Posted by old_master

Quite possibly the actuator in the tailgate is faulty, or there is an open circuit going to the actuator. The only way to tell for sure is to somwhow get the trim panel off and check the circuits at the actuator.

Last night I removed the trim panel and the actuator. There is nothing wrong that can be seen visually. I attached an ohm meter to the contacts on the actuator and got a reading, so I think the actuator is OK. There was no voltage measured at the end of the wires when the button on the key chain was pressed repeatedly. I did notice however, that when the key chain button is pressed twice, there is a faint sound at the dash suggesting that a relay or similar device is activated. There is no sound at all when the button on the dash is pushed. Now I am suspecting that one of the wires is broken or disconnected somewhere other than at the tailgate. Does anyone know anything about how these wires are routed?

[jdmccright]

If the glass hatch won't open even when you press the button on the tailgate then my guesses would be 1) the actuator is bad, 2) the wires to power it are broken, or 3) there's a bad ground wire from the unit. If you can get the hatch/tailgate open, look for the wire loom along the bottom of the and scout from there. Sounds to me like the FOB or the dash buttons aren't the culplrit. Can you unlock the doors using the key in the tailgate? Does the rear wiper work? That might indicate good power to the tailgate unit, leaving only the actuator or bad ground as the cause.

[Rhoneb]

Originally Posted by jdmccright

If the glass hatch won't open even when you press the button on the tailgate then my guesses would be 1) the actuator is bad, 2) the wires to power it are broken, or 3) there's a bad ground wire from the unit. If you can get the hatch/tailgate open, look for the wire loom along the bottom of the and scout from there. Sounds to me like the FOB or the dash buttons aren't the culplrit. Can you unlock the doors using the key in the tailgate? Does the rear wiper work? That might indicate good power to the tailgate unit, leaving only the actuator or bad ground as the cause.

If I turn the key in the tailgate nothing at all happens. The wiper works fine.

Am I correct in assuming that if I remove the actuator and apply 12 volts between ground and one of the wires that the unit would operate as intended unless it is defective? There are two wires going into the actuator. I assume that one of these is supposed to lock the window and the other to open it.

I am heading out of town for the weekend at about 4:00 AM Friday morning, so will not have a chance to look at it again until sometime next week.

Thanks for the input.

[jdmccright]

Remove the wires from the actuator and check for voltage from each wire to ground (you can probably touch the negative probe to the actuator's mounting screws for a ground). From my simplistic Haynes manual, it looks like there is an orange wire routed from the Courtesy fuse 2 circuit (20 amp) that supplies power and the other is a wire from the dash button to the actuator. If voltage is present from at least one, then the actuator is bad. If not, then you'll have to follow those wires back and check for a pinched wire, rubbed off insulation, or other damage to the wire(s).

[Rhoneb]

Thanks to all those who replied to this with suggestions. Thanks especially to jdmccright who posted the following information:

From my simplistic Haynes manual, it looks like there is an orange wire routed from the Courtesy fuse 2 circuit (20 amp) that supplies power and the other is a wire from the dash button to the actuator.

I thought I had checked all of the fuses, but I was wrong. Unfortunately the users manual is worthless for problems associated with the rear hatch window, and I don't have access to any kind of wiring diagram. Knowning which fuse it was supposed to be, I checked it immediately upon returning from my trip and discovered that it was defected. Replacing the fuse resulted in a fully functional hatch window. Thanks again for the help.