Help with 86 K5 Tailgate

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Matt Wettig

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I bought a 1986 K5 Blazer. When you put the back window down it stops with about 3 inches of the glass sticking up. And then when you pull the inside handle it will not open. Someone told me there was a safety switch in the tailgate. Can someone give me an idea what it going on with it? Motor seems strong. Window goes up and down good it just doesnt go all the way down. Any help would be appreciated. Thanks in advance.
 

Mr Clean

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It could be the previous owner worked on it and didn't have the gears in the proper position when they put it back together. Could be your side tracks are out of adjustment. The safety switch is towards the bottom on the tailgate so if your window isn't going all the way down, you are not engaging it.

You can take the cover off, and check if the gears are engaging all the way down.
 

Matt Wettig

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Ok thanks. I was going to crawl in the back and take the cover off and see what was going on. Just wanted some feedback before I did it.
 

GTX63

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Once you have the cover off you can check for binding, misalignment, lack of grease, etc, but you can also unhook the drive cable and attach it to a drill to confirm if you have drive motor issues.
 
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Matt Wettig

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Ok thank you. I will advise after I look at it.
 

Matt Wettig

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Well I got it apart today. First thing I found is someone has bypassed the safety switch. There is a linkage that goes below the latch mechanism. It has a spring on it and fits in a plastic clip. Spring was broke. Plastic clip is broke and the linkage was laying in the bottom of the tailgate preventing the window from going all the way down. I liked to never got the tailgate open. When you pull on the handle it barely moved the rods. I tried adjusting it and it didnt do any good. Had to pull on both rods to release gate. Latches are way out of alignment also.
 

KDizzle

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Engine Size
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Hello, glad your issue go resolved. Figured I’d jump on this thread since I’ve got a similar issue.

Got an 86 K5 also. I replaced tailgate key cylinder to match doors in order to use one key for all three cylinders. Decided to grease the rear window regulator. After putting everything back together, it seemed to be working fine until my tailgate key cylinder fell out yesterday. Decided to take out regulator and grease small gear too. Also flipped the key cylinder right side up since it was upside down when I first installed it. Reassembled everything and now window barely goes up and down, to the point I have to help it. This was not the case yesterday. Also, it’s worth mentioning the motor and cable are new. Don’t have a safety switch. Thoughts?
 

KDizzle

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Failed to mention, window goes up and down like a champ when cordless drill attached.
 

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