Main Relay Question - Control line from Gauge Cluster

[gt500blue]

I hear ya.... I did swap ECM and still no difference. But the ECM from the "bad" ski worked perfectly fine in the "good ski". So unless there was an issue with the wire in the harness, I am not suspecting that the ECM is "thinking" that it should be locked, thus not telling the display to ground the relay control wire. Make sense?

[casey67]

Most times I take words litterally. To me the test "lock ECM", it's testing if in fact it is in lock mode,capable of lock mode.
If you had the correct tool to remove the pin from the "weather tight" connector, removing the B/G wire and it's 5v would verify my theory.
Most car "security" function is pretty simple, most just interupt the starter. Jump the starter and off you go.
I think yours just keeps the fuse box from being powered up. The ECM does the thinking and cluster has the switch that keeps from grounding the relay. And if it has other electrical issues, likely that switch circuit is inop.
You could also test the good ski to see how it's supposed to work. But I'm guessing your fedup with testing by now.

[gt500blue]

Thanks... Yeah, I said previously, the cluster flickers but does not power up completely when the lanyard is put in place. All of the LCD segments flicker and jump around. When I get some time (tonight I hope) I'm going to build a jumper harness to connect the display from the working ski to the bad ski to see if it fixes the issue. I did perform the "lock ECM" test per the service manual and it says it should have 5 v, which it does on the Blue/Green wire. I'm still not understanding the correct function or sequence that would ground the LG/BL wire to the relay. But it has to come from the display. Now if the ECM "tells" it do ground it our not, I just don't know.

[casey67]

Diffenetly do not ground B/G wire. It more then likely works by having 5v or not having 5v from the ECM.

My thoughts are somehow the cluster is not switching LG/BL to ground or not being told to switch to ground.
Since the cluster is capable of shutting off the main power, I think that IS the lock function.

You just mentioned the cluster does not work ??
If the buttons are inoperable then I do think the cluster is your issue.

[gt500blue]

Thanks for this again! I do not think the lock is the issue. The ski starts without any lock code action (I have never set the lock code) as it should once the relay gets ground on the LG/BLK wire. I do not believe the ECM is locked out or the ski would not start as the LG/BLK wire goes directly to the relay and not the ECM. That wire is the relay control input and is not controlled by the ECM from physical wire tracing and the wire diagram. If the ECM was locked out, I don't think the engine would run regardless of the LG/BLK relay control wire being grounded as the ECM does obviously control the ignition system. Make sense? I could force the B/G lock wire to the ECU to ground to see if there is a difference, but the service manual says normal operation is 5V with the lanyard installed, and I have 5.1v on that line. I'm hesitant on forcing it to ground (or a higher battery voltage) as I do not want to inadvertently lock the ECM since the display is not working, it will be nearly impossible to unlock since I would not be able to enter the necessary buttons to unlock per the manual (and the post you shared).

John

[casey67]

Sorry I dont have more experience with this. I used to complain about really long diag trees with Ford, I guess no tree is worse .Reading some posts didnt offer a solution. Someone with same issue simply rewired it (I suspect bypassing the "lock" )

I agree, trying the other cluster would be the easy test. The flickering is worrisome, a loose connection/solder joint.

I found this for unlocking the system: http://greenhulk.net/showthread.php?t=222046

I would like to see the 5v on B/G toggle on/off. Or possibly remove the wire from connector to see any change.

[gt500blue]

Thanks for sticking with me on this! There is no diagnostic tree. Simply a section in the service manual for the display that has the various tests/mearsurements and what the results should be.. It does not say what is wrong if something does not pass the particular test. If a value is wrong, it tells you which wire should be checked for short or open, but it does not describe the functionality and what the test really means in the big picture unfortunately.

I wish I could find a manual that describes the system power up sequence. I'm not sure how the LG/Bl wire is supposed to be tied to ground. There are no descriptions of the sequence or correct operation of the system. Just several checks to perform and they all pass. But since the display is not powering up fully, I think it's the best guess as the culprit. But I'm open to more input from you and others on this forum.

And thank you again!

[casey67]

The ECM lock procedure is to put a jumper between light green/black and green wires on the 10P connector. Then to measure voltage with lanyard installed between blue/green and green. Should be approximately 5V. Mine tested at 5.1 volts.

.

Jumping those 2 pins powers up the system/ECM. Having 5v means the ECM is sending that 5v. Does the diagnostic tree claim a part is bad if that passes ?

How do you "lock" the system ? Could you toggle that 5v on/off ?


I am guessing a simple on/off switch, either in cluster or ECM that alows LG/BL to ground when unlocked.
Many car ECM's use a really low amperage "signal" on a circuit to see if it's intact, when it shows ground it knows things are OK.

Does diagnostic tree recommend trying another cluster if it doesnt power up ?

[gt500blue]

I'm debating in my mind whether or not I should pull the display from the working machine to test. I also don't want to blow it out if there is something wrong with the harness (but all test indicate the harness is okay). Pulling this cluster out is not a trivia task, so I may take some thermostat wire (my son is an AC tech) and build a set of long jumper wires to connect the cluster from the good machine to the dead machine to see if it works. If so, then it looks like I'm dropping around $700 for a used display on Ebay (ouch!). If not, then I'm still hunting. I just don't understand how the cluster grounds that wire if the test procedure calls for 12 volts to be present at the same time with lanyard in?????? But I'm pretty certain making a long 10pin jumper cable and an 8 pin cable is a lot less work than pulling the good unit out of the good machine. Ugh....

[gt500blue]

Wow.. just typed a very detailed response and when I hit reply to message, it all disappeared. I should have hit post. Doh!

So in short this time, there are several test procedures in the service manual that run through power/ground lines, backup voltage wire, power input wire, output circuit to main relay wire, limit mode, buzzer test and ECM lock. All measurements resulted in perfect values, so I think the wiring is NOT suspect.

The ECM lock procedure is to put a jumper between light green/black and green wires on the 10P connector. Then to measure voltage with lanyard installed between blue/green and green. Should be approximately 5V. Mine tested at 5.1 volts.

Also tested the diagnostic switch (whatever that is??) by jumping light green/black and green on the 10P connector and measure voltage between green (10p connector) and pink/blue (8P connector) with lanyard installed. Should be ~5V. Mine measured 5.11 volts.

So my original question is to find out how the relay control signal (light green/black) wire gets grounded. I'm confused because the test procedure for the "output circuit inspection" of the cluster is to put in lanyard and check voltage between the light green/black wire and green (ground) both in the 10P connector. It is supposed to be battery voltage. Confirmed to be 12v... so when/how does that light green/black wire go to ground to power up the fuse box via the master relay? All I know is that when I force the light green/black to ground with a jumper, everything works except the display still flickers. The fuel pump spins up once that wire is forced to ground. When hitting the start button, engine cranks.

[casey67]

Wow, what a mess of a diagram. I should be more careful of what I ask for.

I agree the LG/BL would ground to activate main relay/fuse box.

I am curious about the "lock" function. It does'nt seem to interrupt the starter function, so I assume it interrupts to "main power".
What signal do you get on the BU/G wire at the cluster ? (cluster side of harness BU/O)

Sorry,this is where some experience would be useful.

[gt500blue]

This diagram fits on one page.

[gt500blue]

Aquatrax Wiring Diagram

Trying to attach wiring diagram

[gt500blue]

I tried to make a screen snip and post, but it is being moderated. I have a .pdf of the entire shop manual, but too large to post obviously.

Any suggestions on how to post just the wiring diagram? Thank you!

[gt500blue]