Rear Window Glass Struts

[bocoogto]

I've replaced the struts on my '93 Roadmaster twice in ten years---not because they didn't hold the glass up, but becaused they failed electrically. If there is no electrical continuity between the top and bottom of the strut, the rear window defroster doesn't work. The last time I bought them, I took an ohmmeter along to the store and tested the ones on the shelf. I picked two that had continuity, but they didn't last very well.

Has anyone else run into this problem? If you resolved the problem, what kind of struts did you use? I bought the replacements at Autozone and can't find any receipts for exchange. There is no ID for manufacturer on them, just a part number 9762.

[j cAT]

If you don't have the rear window defroster working...the rear window should not have any effect on this defroster power supplied...I would check ground wires and feed wires for connection issues...to the defroster heater grid...ohms/volts..

[bocoogto]

j cAT,

Power to the rear window defroster is supplied through the struts that hold the window open. When the rear window heater is turned on, +12 volts is applied to the grid in the window on one side through the strut. On the other side, chassis electrical ground is connected through that strut. I've already checked to see that +12 volts is present through the strut to the grid. The other side also measures +12 volts on the grid end of the strut, but on the top end of the strut, there is continuity to chassis ground. This indicates this strut is electrically open. No need to do any further troubleshooting. The problem is the strut.

['97ventureowner]

Originally Posted by bocoogto

I bought the replacements at Autozone and can't find any receipts for exchange. There is no ID for manufacturer on them, just a part number 9762.

The last pair that went bad, did you get those at Autozone? You might be able to exchange them by your sales history in their computers. In my area, when you buy something that has a warranty, the sales person takes your name, address, and phone number. If you bring the item back defective or in need of replacing, they can look up the receipt by your phone number or address.

[j cAT]

Now I understand.. this is a roadmaster wagon.. and this is the end gate window....the channel supports are making the conductive path for the grid... so it appears that you lost the ground side...

you should try a different manufacturer...

[bocoogto]

Yes, that's what I am leaning toward. I can wiggle the strut while energized and see sparking at the window end of the strut in the area where the electrical terminal is located. Evidently, the electrical connector piece is shaped into a ring that surrounds the cylinder rod. It only makes intermittent contact from one end to the other of the strut.

Other brands may be manufactured differently so this is not a problem. That's the info I'm looking for in this post.

Otherwise, I go to Autozone with an ohm meter and check stocked struts until I find a good one.

[j cAT]

Originally Posted by bocoogto

Yes, that's what I am leaning toward. I can wiggle the strut while energized and see sparking at the window end of the strut in the area where the electrical terminal is located. Evidently, the electrical connector piece is shaped into a ring that surrounds the cylinder rod. It only makes intermittent contact from one end to the other of the strut.

Other brands may be manufactured differently so this is not a problem. That's the info I'm looking for in this post.

Otherwise, I go to Autozone with an ohm meter and check stocked struts until I find a good one.

I believe that this part may be not the correct part, as this current to heat the glass is quite large...auto zone will return your money if it has a warrantee...

you could put a wire along the strut to get the return to ground.

[bocoogto]

The strut I have is not the wrong part. The electrical connection on each end was put on at manufacture. Yes, a large amount of current is required for the glass.

Don't forget, both the left and right struts conduct the same amount of current. Either one being open electrically disables the defroster. An extra strap such as a coiled cord would be pretty hokey. I prefer to find a pair of working struts.