I'm trying to diagnose my trunk motor operation not working. First off (THE MOTOR IS GOOD)! I disconnected the motor switch that connects to the two prongs coming off the motor and gave the motor straight power from the battery and it worked and the assembly went up and down, I had to reverse the wires to make the direction change because polarity I guess, but the point is the motor and assembly did go up and down when I gave the motor direct power from the battery.

So now I'm trying to figure out why when I hit the trunk release switch from the center console, nothing happens.

IS IT POSSIBLE TO HOOK UP THE CENTER CONSOLE SWITCH BACKWARDS, TWO SINGLE WIRE CONNECTORS THAT CAN CONNECT TO EITHER TERMINAL ON THE SWITCH...?

ALSO IT COULD BE MY IMAGINATION, BUT IT FEELS LIKE THE RELAY IS HOT TO THE TOUCH EVEN WHEN PLUGGED IN FOR ONLY A FEW MINUTES... IS THIS NORMAL, IT'S A NEW RELAY, BUT THE OLD RELAY FELT HOT TOO.
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Here is what I have done so far:

1. Checked the fuse in the fuse box labeled LID 15amp fuse, it was good.

2. I put my volt meter probes on the tabs of the trunk release switch from the center console and was reading good voltage from the battery, no key in the ignition as I guess this is always hot, then when I press/push down the switch I watch the voltage drop down to 0 and when I release it, it goes back up to battery voltage, so I'm guessing the switch is good and doing what it is supposed to do?

3. I replaced the relay in the trunk cargo area

4. I used a test light that was grounded and probed the backside of the motor switch connector while it was plugged into the motor and here's what I got

wire #1 probe lit up constant
wire #2 probe lit up constant
wire #3 probe did not light up
wire #4 probe lit up constant
wire #5 probe did not light up

NOTE: while probing each of the wires, I pressed down and released the up and down switch at the top of the motor housing assembly, the part that tells the motor when it is down far enough and up far enough, and on all of the wires it made no change in the way the test light operated, in other words the light didn't go on or off depending on whether or not I pressed that switch down, it made no difference at all. According to the video I posted a link of, it should have? What does this mean? is that up and down switch bad?

5. I probed the 3 wires coming from the up and down switch going to the motor switch here is what I got.

Black wire = constant light
Black/orage = light on, then light off when the up down switched is pressed
Black/yellow = no light, then light on when up down switched is pressed

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I tried testing the wires with the relay not plugged in and I got different results:

wires going from relay to motor:

wire #1 = constant light
wire #2 = light on, then off when up and down switch is pressed on the trunk motor assembly
wire #3 = no light
wire #4 = constant light
wire #5 = no light


wires going to the motor switch from the up and down switch

Black wire = constant
Blk/orange wire = constant
Blk/Yellow wire = no light, then light when up and down switch is pressed

NOTE: all these testes were done with no key in the ignition
Also I think there might be a relay in the center console area? I haven't replaced that if there is one. Have I missed anything? Based off this info, can anyone tell me what the problem is?

thanks.

 

Bump.... anyone have any ideas or suggestions? Thanks!

 

Let me access wiring diagrams tomorrow at work to look and I'll respond. You seem to done a very thorough job diagnosing, I just want to see the schematic to know what I'm talking about.

 

Thank you!! :-)

 

These are the diagrams for the hatch release system. Review them and let me know what I can help with

 

Ok, thanks. I tried to enlarge the schematic t a little so I could see it a bit better but it wouldn't let me. I'll check this out though and get back with you soon. Thanks so much!

 

@neilcase Might be able to help you with troubleshooting the problem. He's the member you bought your ECM from on eBay. He services and sells these units too including the rare late 1991.5/1992 only unit like you and I have.

 

Oh good, thanks!!! I'll reach out to him.

 

Did I sell this fella an ECM or a Hatch motor assembly? I sell both of those items. Based on the problem description it sounds like he has a bad console relay.

 

You sold him a 1228746 ECM with a AKXT chip. Was exactly what he needed for his car. His ECM wouldn't go into diagnostic mode or control his IAC motor. Fixed him right up. Killed two birds with one stone. He got a good ECM and the correct Memcal for his car to replace the bad ECM and HyperTech chip that was installed in it.

Hopefully he left you a nice eBay feedback.

@Tuned Performance turned him on to your eBay listing for the ECM & Memcal. I added you to my Saved Sellers list in case I need some parts for project cars in my friends 3rd gen collection.

 

Thanks guys. I'll check out the console relay, since, as you suggested, that might just be the issue here.

 

You sold me the ECM and PROM combo which worked out great; I just left you a great review/feedback on EBay.

When it comes to the console relay, correct me if I'm wrong - are you saying there's 2 relays in the wiring harness? One near the trunk motor and 1 in the center console? Because I've replaced the one near the trunk already.

 

Pretty sure I found the hatch release relay in the center console. It's the relay with the connector that has orange, brown and black wire on it -a 3 terminal relay. Not sure what the AMPs are for the relay, but the orange wire goes to the fuse block which connects to the 20 AMP fuse so I'm guessing it has to be a 20 AMP or more relay.

When I press the hatch release button I can hear the relay click so I did a few tests. The brown wire that attaches to the release switch is hot (voltage) and according to the wiring diagram, the brown wire goes to the orange wire going to the hatch release relay (which is also hot). I used my multi-meter to see if the relay was doing anything while operating the trunk release switch. And probing the different terminals while one of the probes was on a ground. I could see that voltage was being provided across the terminals, etc. And voltage would drop off when not using the trunk release switch. Basically, I think the relay is working as it should. I could be wrong, but things kinda look like it should be working. So I think this means that the fuse is good, the release switch is getting power, when the release switch is operated, the relay does what it's supposed to do, and from that point, I think everything points towards the rear of the car to the extend relay, hatch pull down and release unit, and cargo compartment lamp. So if I have a problem, I think it's going to be one of the components in the rear. As mentioned before, I just put in a new relay, so I don't think it's the extended relay in the trunk area. Which narrows it down to I guess 2 things: the switch that connects directly to the motor, or the switch on top of the motor housing unit that tells the car how far down the latch actually is. Does this sound about right? If it is one of these two things, how can I diagnose to determine which one it is? (Remember, the motor is actually is good and runs when direct voltage is applied, so it's not the motor.)

I'm learning how to read these diagrams as I go. One question.... does a thick bold black line on the schematic/diagram mean that the wire is getting power all the time (constant)?

 

Does anyone know where I can get the two switches that are attached to the rear hatch pull-down assembly? Because I know the motor is good and I think the switch in the center console is good, and the 2 relays in the system are good, and the fuse in the fuse box is good. So that only leaves the 2 switches on the pull-down assembly left. And I'd hate to have to buy an entire assembly with motor and all, if mine is good, and there's nothing wrong with the assembly. Thanks.

 

Hello !!
I am following this thread closely as I am having the same difficulty with my 1992 RS. Have you been able to locate and fix your latch assembly?