T_MaX

A few weeks ago I was just about to load the luggage in to shark for a weekend in S.A and when I pulled the switch for the hatch the motor just ran and ran and ran (till I pulled the plug).

Today I decided to take a look at it to see if I could fix it.

Here is what I found and I am at a stopping point unless someone can help me with identifying some surface mounted components.

Hatch Motor help page

ErnestSw

Max, your pictures are not loading.
The sum total of my hatch motor experience is adjusting the two bolts on the car that move the latch back and forth. It seemed to solve a problem in the car I worked on. I wonder whether there's a "clutch" effect when the motor runs into a mechanical resistance. You might try to simulate a fixed point and see whether the motor shuts off.

BrianG

Max, you have to place them on the web, somewhere. Like "Moment of Fame.com".

The Hatch motor cycles 3 times and then parks, much like a windshield wiper motor. I'd wager that your failure is like mine..... a shaft broke loose from it's gear, and the parking mechanism is not functioning. In mine it was the large brown bakelite gear with the metal splined shaft. It looks like it works, but under the working load, the shaft just spins in the gear. Epoxy worked for a while. A solenoid is next.

Mark

The pics loaded for me

BUT - I can't help with the problem...sorry...

Eric G

Max,
Did you check the fuse? I forget which one it is, but one of the fuses in the main fuse panel is needed to stop the rear hatch from going nonstop (I had the same problem - a simple new fuse fixed it)

Niels Jørgensen

Max,

The three-legged thing is a transistor - an electronic switch if you will, the capacitor is not a capacitor but a diode (technically these are not SMDs either, but that's a detail ).

If any of those three are fried, my guess would be the transistor (one of the three legs (the base) opens and closes the connection between the other two - if it's fried "open" that could account for the motor keeping on running). If you feel like soldering a bit yourself, this is probably a $0.50 part, and an easy fix.

But I have no idea if this is in fact your problem.

A silly question: Are you sure it's the motor and not the hatch-switch that's broken?

T_MaX

Check the Hatch Motor help page for updates.

BrianG

Max......... sorry....... Old-times snuck in there. I was referring to the rear wiper motor failure that I experienced, with the splined axle issue.

On this failure, the failed part is the one that is on the far right of the gear-set in the first of your pics. That is, the black plastic cap that is driven by the gearset that you show. It contains the metal ball-joint ball. When I removed the central mounting screw and removed that cap-unit, I discovered that the central portion of it (the square-shaft portion that is actually engaged with the drive) was sheared from the rest of the cap. This isn't all that apparent at first blush, but will be if you remove the central screw.
This allows the motor to cycle without actuating the opener.

YMMV

BrianG

Max, I believe that that sharp piece of metal is part of the grounding point for the metal case. This allows the case to function as the circuit ground for the unit.

T_MaX

Last night I started cleaning up the two case halves and noticed the side of the case has a crack in the neck. I have some pictures tomorrow.

Niels Jørgensen

Max, first of all, I don't really think it's the electrical circuit that's troubling you, so don't waste time going that route unless all else fails (when unsoldering parts you run a high risk of causing dammage that wasn't there in the first place).

That said, and it has been a long time since I messed with electronics of any sort, but as I recall, you don't need to find an exact match. An identical type (PNP or NPN) is required, and it should have the same voltage/amplification rating, but usually there's a ton of different transistors that will get the job done - take it to radio shack and I'm sure they can find a replacement.

Finally, a wild shot: There must be a wire going into the motor that carries the signal from the switch to trigger it. How about attaching a lightbulb to this wire to verify that the start-signal is cut when the switch is released. If so, the motor is probably the problem. If not, there must be a relay somewhere that keeps the signal after the switch is released, or, the switch is broken and stays open.

T_MaX

Thanks to all for your help so far. I am not giving up, just have a few priority tasks to do.

I have updated the Hatch Page , I know it's a long page just scroll to the bottom for the latest. I am going to break it up in to two or three pages when I get time.

Thanks again

WallyP

As you have discovered, the problem is that the inertial effect of the motor is enough to over-run the little cut-out in the metal disk.

Some possibilities:
Pack the gearbox with some good, soft, sticky grease to reduce the amount that the motor can coast.
Increase the size of the cutout slightly.
Stick a power resistor in the run-on line to slow the motor slightly.

T_MaX

Wally, all viable options, I wish I had some spare parts to test the different options. I love to play with stuff like this!

As is, I'm putting my chips on a few ease replaceable electrical component (s) being defective (replaceable with a fair skill level and instructions).

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Copied from another thread, same items in question.

Dozman writes;

Max,

The resistor that has three legs is actually called a Triac. That is the proper name for that type of non-mechanical switch. They are usually very reliable as compared to a mechanical switch.


Dozman, I just want to clear this up, for myself any other (lo-techies).

Question: A transistor is a switch (s) and resistor(s) combined in one unit and the word Triac is the type of Transistor or Resistor?

Dozman

A triac, is a transistor that is now commonly used to open and close an electrical gate. It is considered technically a thyristor.