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Resolved 2G Is this connector important?

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waltah

10+ Year Contributor
368
156
Mar 2, 2011
fairfield, Virginia
Trying to get my '95 GS-T parts car to crank so I can test compression. This connector is the only thing that's still hanging loose 'cause I can't find where it goes. It's under the front of the battery bracket. Spliced on (badly) so it may not be the standard connector for whatever it is.

I'd like to know what this is so I can either hook it up or ignore it. My 'driver' GS-T doesn't have one of these -- only difference is it's auto, this is manual shift.

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The car came as a semi-basket case with a lot of stuff unhooked, few things (like fuel injectors ...) missing but "it used to run but then Tommy started to work on it ..." When I switch on ignition the ECM lights up CE for five seconds and the boost gauge comes up to zero but when I turn it to start, nothing happens -- no faint click, nothing.

I think there is a whole thread on 'Car won't crank' and if someone will point me to it, I'll go there. Couldn't find it with search.
 
Solution
And at last the answer to "Is this connector important?" Yes!

With the new radiator cap installed I let it run a bit longer and suddenly CEL lit up. P0115 -- Coolant temperature sensor malfunction. It took me a while to find the darn thing -- why don't those sketches showing the location of sensors at least have an arrow pointing to the front of the car? But -- sure enough -- there was nothing plugged into it and since it was near the Mystery Connector I tried hooking that up and after some fiddling it went together.

The reason that doesn't look like the coolant temperature sensor is that the shell is completely gone. All that's there is the inner insulator and pins with part of the latch. I actually have a...
I don't recognize it. Can you see where it goes?
Whats the status on this car anyway? Has it ever cranked? Don't forget you must press clutch in to start. I would at least check and see if the starter solenoid is getting power and backtrack from there.
 
Was that an old-guy joke ? 😄
Made me laugh.
It's worth mentioning as not everybody has disabled the clutch switch. In addition, I've seen cars where the clutch switch pad on the pedal assembly deteriorates or falls out completely and won't press the switch. Imagine diagnosing that one.
 
I don't recognize it. Can you see where it goes?
It's a two pin connector that goes into the harness. They're very small pins -- more like a sensor than the starter solenoid. I can probably get the color codes on the wires it's spliced to as another clue.
Whats the status on this car anyway? Has it ever cranked?
It was said to be driven by the PO who later unhooked most of the engine harness in an attempt to fix 'lost power' whatever that means. This is my first effort to make it crank.
Don't forget you must press clutch in to start. I would at least check and see if the starter solenoid is getting power and backtrack from there.
Actually I did at first forget the clutch switch but when I looked at the starter circuit diagram, DOH! In my defense, (a) I'm old enough to forget things that old guys are supposed to know and (b) my other stick shift has the switch disabled.

I will check the switch though -- might even be disconnected like so much other stuff. If that's not it then it may be a theft alarm issue. Both front door handles were smashed in, the lock cylinder switches broken, and both latch assemblies pretty well destroyed -- the PO said it was that way when she got it. So the odds that everything the theft alarm system checks is okay aren't 100%.

On the other hand, the car was being driven and I doubt the PO could have fixed or bypassed a TA problem.

Car came 'starts with a screwdriver' and the ignition switch dangling out of the column. I made the key, fixed the two door cylinders to match -- key was made to fit trunk cylinder and worked properly in the ignition lock but when I found the door cylinders in the bottom of the trunk it didn't work for them. So some PO had replaced the door cylinders before the handles were smashed in. That car has had a hard life.

Great comments! Thanks!
 
I've seen cars where the clutch switch pad on the pedal assembly deteriorates or falls out completely and won't press the switch. Imagine diagnosing that one.

It wasn't too hard to find when mine died. You could hear the starter relay click which is a strong clue there was a problem with the CSS and once I got upside down in the footwell you could see the problem. Pull the connector, drive to the dealer, get new part, done. :)

Trying to get my '95 GS-T parts car to crank so I can test compression.

Have you checked the starter to see if the solenoid wire is attached and that you're getting 12v to it when you trying to spin it? Checked at the ignition switch to see if you're sending 12v on the start terminal?
 
Today I disconnected the starting relay -- since the console was already out (from when I got it) that was easy and lots of stuff can be checked there. Had no voltage from the start contact of the ignition switch so pulled the switch itself out -- since the column covers were already off and the switch dangling (from when I got it) that was easy. Sure enough, the start contact had burned away -- this is a regular problem in all Mitsu models of those years.

To repair the problem pop off the back of the switch -- hold it black side up so the innards don't fall out when you do. I think it'll only assemble one way but if you just leave the copper plates and other stuff in the white part there's no need to know. Slightly file down the nylon runners that position the copper contact plate. Do just a little at a time and try it in the car as well as with a small flat screwdriver by hand -- the lock cylinder will not rotate the switch as far as you can with a screwdriver.

Note the little holes in the black back that allow testing even with the switch hooked up.

New switches are available -- $30-70 -- but I'm too cheap to start there. Repaired switches last a long time.

This one still only works 5 times or so before something in the switch (?) heats up (?) and you have to wait 30 seconds but that's plenty good enough for testing compression.

Comp. is probably okay -- it sounds right.

Except for the funny little connector everything I could find in the engine compartment is hooked up and the ECM does the right start up dance (and it worked fine in my driver) but not a pop from it when cranked so once compression is tested I will get to diagnose a case of 'Cranks -- no start.'

The funny little connector looks right for the theft alarm horn. Also could be for the evaporative emission canister as suggested above. That's in the same territory. The connector is on 3" pigtails twisted to 1" wires from the harness in that area (from when I got it) so I was not able to see the color codes without pulling other stuff.

This car has had a hard life. Who smashes both door handles to get into a car? I've got new handles, the cylinders are okay, but I gotta find the (electric!) latch assemblies -- both of them were destroyed too.
 
This one still only works 5 times or so before something in the switch (?) heats up (?) and you have to wait 30 seconds but that's plenty good enough for testing compression.

once compression is tested I will get to diagnose a case of 'Cranks -- no start.'

If you decide you'd like to do your cranking with a nice inexpensive generic heavy duty switch instead of that stock thing, there is a nice one sold by Del City and Wiring Products. 50 amp momentary, made for "harsh environments".
You would need a flat panel with a 5/8" hole in it to mount it though. I have 2 pics that show mine on my "Specs and Photos" page.
Here are links:

https://www.delcity.net/store/Heavy!Duty-Push-Button-Switch/p_8065.h_173706

https://wiringproducts.com/products/heavy-duty-50a-push-button-switch

Mine are black rubber covered (I have one in the car and one spare). It looks like the ones Del City has in stock at the moment are red rubber covered. I don't know why their prices are different. I think they are the same switch. I bought one from each.
 
Some of today was in the 'you can't make this stuff up' department.

Went out to do the compression test. There was a humming ... no, more of a buzzing sound when I got in the car. I got out real fast when I figured out it was the sound large wasps make when disturbed and it was coming from inside the driver's door. Trim pads are currently off, so ...

Wasp spray quieted things down; I hope that stuff doesn't damage plastics or electrical parts inside the door.

After being 'sort of okay' last night, today the car wouldn't crank at all with the key. So I took off the switch and used a screwdriver again. But after 20 or so revolutions, #1 only read 50 PSI. ??? Another 30 revs and she's up to 100. (Bulb lights up over my head) Last year I borrowed a compression tester from Autozone. It was defective -- almost 100% clogged up inside so it would only register very slowly. I took it back, talked to the manager, he promised they'd get rid of it. I got another tester that they had in stock and it worked fine.

So what do you think they gave me this time? Only today I didn't have time to spend taking it back and getting the good one before doing the test. So -- I cranked a hundred revs or so and let the starter rest (cool) before testing the next cyl. All tested 170-180 PSI but I didn't try to get exact readings because that's enough to be sure it's fine, compression wise -- spec is 178.

Good oil pressure on the gauge, too, but the idiot light was still on. Have to troubleshoot that -- it's OFF if disconnected, isn't it?

Next was check for spark. Pulled plugs, gaps all 0.036+, should be 0.028-0.031 for turbo car. Adjusted. Hooked up plugs & laid 'em out on the valve cover, wife watched while I cranked with the screwdriver in the switch. 2-3 had sparks, 1-4 did not. I've got a spare transistor assembly and I'm pretty sure I've got a coil so in a couple days the spark problem should be fixed.

Studied the ignition switch some more: The plastic inside the rotor is worn (sort of dug out) so the lock cylinder won't turn it the full distance and there's no really good way to fix or fudge that.

There is a JB Weld putty and in a different situation a BB-size pellet of that inside the switch rotor, put it all together and let it sit overnight might work. Or ... it might glue the lock cylinder solid. Not gonna try it.

Amazon Prime claims I'll have a new switch on Sunday. There seems to be some gas in the tank and I've got a set of wheels with tires that don't have steel plies sticking out so who knows?
 
I moved the battery over to check the theft alarm horn -- that's not where the mystery connector goes. Answering that question will wait until I next remove the battery.

Another round of screwdriver-in-switch, and wife watching sparkplugs: Yes, 2-3 are fine, 1-4 not, particularly #4 which sparked only sometimes. Probably not a coincidence: #4 plug was not carboned up like the other three -- just oil-moist.

I plugged in a spare transistor assembly; same story. Plugged in a spare coil pack and all four plugs lit up.

Screwed 'em in, shot it with starter fluid (age of gasoline in tank is ??? -- over a year) and VAROOM ... A fairly loud varoom 'cause the rear muffler is off of it.

It does not run really well. The ECU does control the RPMs, oil pressure is fine, no CE light (after the first five seconds) but if you run it up to 1500 or so it misses now and again. Letting it warm up might help, ditto some new gas.

No CE light says that whatever that connector is, it's not very important. I think the evap. canister is only tested during a drive cycle so that's a good possibility.

I swapped to a decent set of wheels/tires tonight, tomorrow I'll change the coil pack then bolt the radiator on as well as possible -- it's the right shape but about 1" too narrow for this car so the support brackets don't work. Then Install the new ignition switch, figure out why the emergency brake doesn't work, and be ready to drive it in circles on the front lawn. Then reinstall the rear muffler, headlights & bumper covers, maybe replace at least the driver door lock ... I'll copy this story to a build thread and continue there.

My wife's daddy had a foreign car repair shop so she's used to this stuff. Unfortunately the family cars were all foreign cars abandoned by his customers so it has taken a while to get her to accept driving my (formerly abandoned} foreign cars.
 
And at last the answer to "Is this connector important?" Yes!

With the new radiator cap installed I let it run a bit longer and suddenly CEL lit up. P0115 -- Coolant temperature sensor malfunction. It took me a while to find the darn thing -- why don't those sketches showing the location of sensors at least have an arrow pointing to the front of the car? But -- sure enough -- there was nothing plugged into it and since it was near the Mystery Connector I tried hooking that up and after some fiddling it went together.

The reason that doesn't look like the coolant temperature sensor is that the shell is completely gone. All that's there is the inner insulator and pins with part of the latch. I actually have a replacement for that connector so one of these days ...

With it plugged, the car starts first try even when cold. It doesn't run well, but it does run and it smooths out as it warms up a bit. The various air settings are just rough; maybe that's why it doesn't run smoothly.

An unhooked connector would look like an extremely cold engine so that would make it far too rich, explaining both 'hard to start' and 'the plugs are black with soot.' Only thing I'm not sure about is why it took so long for the ECU to discover the problem.

After resetting the code I ran it for five minutes or so and CEL flashed on again. P0135 -- O2 Sensor Heater Circuit Malfunction. So I've got some diagnosis to do -- voltage getting to heater, heater resistance ...

This also took a while for the ECU to notice but the explanation for that is it watches for switching between rich/lean and only flags a heater failure if it takes too long.
 
Solution
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