Hatch Latch Resistance
Thread Starter
Joined: Jun 2008
Posts: 841
Likes: 7
From: South Pasadena, CA
Hatch Latch Resistance I need some help. I swapped my 1998 latch to a used 2002 unit, which works, but the internal switch for open/closed doesn't seem to be sending a signal to the car. Can someone with the later style latch (I believe 1999-2002) which has the external spring on the passenger side check resistance for me? This would do me a huge favor to know if the latch I have is bad, or if they all work this way.
It isn't too hard, but it requires you to use a volt-ohm meter. If you can, here are the steps:
It isn't too hard, but it requires you to use a volt-ohm meter. If you can, here are the steps:
- Open the hatch and pull the lining over the lower latch so that you can see the wiring around it.
- Find the 2 wires going straight out of the bottom of the latch (not the ones on the side for the solenoid).
- Unplug the connector. There is a clip on the side, but it is very easy to lift with just your fingernail, you don't need tools.
- If you look inside the connector coming from the latch, there should be 2 pins.
- Take your volt-ohm meter and set it to read resistance Ω around the 20K setting should be fine.
- Touch one probe to each of those pins, making sure not to let the probes touch or it will alter the reading.
- If it says "1," that is infinite resistance, meaning open switch/circuit. If it goes to 0 or near to it, that is a closed switch/circuit, which is also what it will show if you touch the probes together. Let me know what you get on yours.
- Repeat the process, but this time get a reading with the trunk closed (careful not to pinch the trunk lining in the latch). You will either have to fold the back seat and crawl over it, or you can fake it by latching a screw driver into the lower latch to artificially close it. When you finish probing, use your key or remote to get the latch open and lift the screw driver out to reset the latch if you use this method.
- Again, take a reading, this time with the trunk closed, and let me know if it is 1 or 0.
Joined: Nov 2003
Posts: 11,329
Likes: 346
From: Jacksonville, FL (originally from Toronto Canada)
The hatch release is an electric solenoid so it will have some small resistance. It will never be 0 (closed) or 1 (open) unless it is damaged. The BCM controls the coil side of the hatch release relay which sends power from the PWR ACCY fuse to the hatch release solenoid to move the release mechanism. If you suspect that you may have a defective coil in the release solenoid then you'll have to use a much smaller range in the ohmmeter to see a difference. But that would be very unusual - these things are usually all or nothing... they work or they don't.
Thread Starter
Joined: Jun 2008
Posts: 841
Likes: 7
From: South Pasadena, CA
The hatch release is an electric solenoid so it will have some small resistance. It will never be 0 (closed) or 1 (open) unless it is damaged. The BCM controls the coil side of the hatch release relay which sends power from the PWR ACCY fuse to the hatch release solenoid to move the release mechanism. If you suspect that you may have a defective coil in the release solenoid then you'll have to use a much smaller range in the ohmmeter to see a difference. But that would be very unusual - these things are usually all or nothing... they work or they don't.
Joined: Nov 2003
Posts: 11,329
Likes: 346
From: Jacksonville, FL (originally from Toronto Canada)
No problem. This is still not something that anyone needs to measure. The hatch ajar switch is a simple grounding switch which is closed when the hatch is open. Power flows to the switch from the GAUGES fuse through the hatch ajar indicator light via the orange/black wire and then to ground via the black wire. In other words, the switch will show infinite resistance (open) with the hatch closed and no resistance (closed) with the hatch open.
Thread Starter
Joined: Jun 2008
Posts: 841
Likes: 7
From: South Pasadena, CA
Thank you. This is what I was trying to determine. My old one works this way, but the new one shows 1 (closed) no matter the position of the hatch open/closed. I wanted to make sure that the newer design works the same way, before buying another latch to replace it.
