Since then, I have received a replacement pigtail connector that I soldered into the engine wire harness hooking the wires up correctly to the existing wire color code. (yellow, black, black w/white) and have now tried two separate used speed senors. However, the speedometer is still not working... no cruise or active aero either. Everything else works, fuse 11 is good.
I have tested for positive and ground at the pigtail connector and are getting both, but not from the wires I was told by escape-performance going by the wiring diagram he was using.
Fact- my positive wire is solid black and ground wire is black w/white stripe, yellow is of course the wire going to the ecu. His diagram said the opposite though- solid black is ground, black w/white is positive... but that's not the case with my 1991.
At any point did Mitsubishi switch/change the engine wire harness section going to the speed sensor so that the sensor's ground wire was solid black and positive was black w/white? I can tell that the pigtail is from a newer year as my "yellow" wire is more of a dingie yellowish clearish looking rubber, but the wire coming out of the pigtail is a nice solid yellow.
Hopefully tonight I will have the time to send 12v to the yellow wire at the pigtail, and using a test light at the ecu connection confirm that the yellow wire is still good all the way to the ecu. If it is still good as I think it will be, then what else could my problem be? The bottom gear section still seems to be fine as the pin won't turn, but I haven't pulled it out to confirm 100%.
Could the ecu have gotten screwed up when the sensor fried? (eveything else works and car still runs great though?!) Or is it just bad luck with the used sensors both being bad? Escape-performance sent me another used replacement already at his expense but it's still a no go as well. I'm positive it's not the gauge cluster because cruise isn't working so it's surely sensor, connection or ecu related.
This has been a confusing thread to follow, but Steve and I have fixed a car using more forum pages than 5.
Thanks for posting the speedo drive unit from the trans. Now at least I know you have a cable speedo drive and the speedometer should work. There is a separate sensor on the instrument cluster to make a signal for the cruise and other speed related things.
I do hope you guys are talking about the wiring for that.
I've never removed the cluster from a VR4, only my cable driven 91 SL. Is that sensor replaceable? Is there anyway to test it or it be obvious if it's bad?
Side note, I just pulled the washer fluid connection to get the dash light off till I buy another sensor or see if the float even still floats.
With key on I just confirmed that the yellow signal wire is indeed giving 5.2 volts. (I ran the meter's black pin to negative post on battery and red pin to the yellow wire) However, when I run the meter's black pin to negative on the battery, and red pin to the black/white (positive??) wire I get nothing, but red pin to the solid black wire (negative??) and I get 12 volts.
Opposite of that, if I red pin to negative on battery and black pin to the black/white wire I then do get 12 volts. That might be more of the same info but the bottom line is the positive and negative are backwards for whatever reason.
The connector is: black/white - black - yellow
EDIT- I just PM'ed the seller asking if he is 100% sure that the pigtail I received is 100% for the speed sensor, and making sure it didn't come off a dsm or something else where the wires might be switched.
why not repin the connector and see what you get. it sounds like they may have just gotten swapped around. easy enough to try. swap black with black/white
it sounds pretty straight forward. you are getting a good ground from one wire and a good positive from the other. are you sure that they are plugged into the connector properly?
Yep, unfortunately. I wish it was as simple as me mistakenly soldering the wires up backwards but that is not the case.
I think before I swapped them around I'd run 2 wires directly from the battery positive and negative to the 2 connector wires (disconnected from the engine wire harness of course) and leave the yellow signal wire intact, see if then the speedometer would work.
no 12 volt signal from either wire though right? you need to check from ground by ohming it out. not voltage. a long enough wire will give you 12 volts even though it isnt connected to anything. but... there would be high resistance. which you can only check with a multimeter capable of reading ohms.
No 12v, not not with the fuse pulled. Fuse in I get 12v from the black wire. They yellow signal wire gets 5v either way.
So pull the fuse, set my meter's ohm setting to 200 (it's lowest setting) and then what? Black pin to battery positive post and red pin to the connector?
if you get a good clean 12 volts from one of the wires only when the fuse is in then you have your fused power. if you get a low ohm reading between the other pin and the chassis then you have a good ground. match the power wire and ground wires up to the correct pins on the sensor. with the sensor wire to ecu already being good then you should be set. if after this it still doesnt work then the only answer would be the sensor.
this is all regardless of wiring color. its just how wiring works with sensors.
dude im gunna tell you...... if you put 12v to that yellow 5v wire you fried your 5v reference ground in your ecu.....does your car run and other sensors read right? Maybe you didnt. Personally i would just run brand new wires and fuck the old shit. take you 30 mins instead of this dicking around.
Run your black to ground get a switched 12v ignition source for your black white im guessing from reading in this thread. Run a wire from pin 66 on ecu to your yellow and then viola?
well now we can assume that black wire is your fused 12 volt power wire. thats good. now get an ohm reading from the black/white wire to the chassis. use the ground point behind the battery to make sure you get a good gound signal. a low ohm reading ensures that there is good continuity. aka a good ground. if that works then you know that both your ground and power are good. then it would either be the sensor. or just the wrong pins on the sensor
EDIT: pimprn, if you read through the thread you will see that he knows not to touch the yellow wire. its in the middle pin where it should be and is giving a good 5 volts. its the power and ground pins that are the problem and may be a simple fix. i prefer long journey to simple fix then a permanent extar 5 foot of wire i need to try and hide.
I'm not sure how it's a "good thing" since the wires are giving opposite signals, lol, but I know what you're saying. Anyway... with or without the fuse I get a ohm reading of 0.04 from the black/white (supposed to be + wire), same reading as if I touch the meter's pins together.
By the way, the yellow signal wire is on the end, it's got a gold terminal in the harness and a there is a gold prong on the sensor. The black wire is in the middle and the black/white wire on the other end.
Power is supposed to be on the outside. Right now yellow is 5v on the outside like it's supposed to be, black is positive in the middle, and black/white on the the opposite side of yellow is negative.
yes it does. but i dont think thats whats going on here. he was showing how you could get errant values that could make you think something that wasnt true
okay so I found the connector number and the signal wire routing. cant find anything on the power or ground wires though
its connector B-34 that plugs into you speed sensor by the way
Okay. so I found the wire diagram. pins (1-B/W=+12)(2-B=ground)(3-Y=sensor) so everything is correct then. weird that the wires would be swapped like that. can you take a picture for indulgence? im about to head home. i will check for any updates when i get there
Yikes! I step out for a bit and you guys have a party!!
First things first. When I saw Speedy's post I went back and looked at your picture in post 26 again. WTF! He's right, that's a mechanical cable driven gear.
Is that what we're dealing with? How in the heck are you plugging into that?
A major misunderstanding like that could explain a lot.....
The first batch of speed sensors were a bit of a hybrid, the bottom could be used for cable or electronic. The electronic part of the speed sensor goes over the small square peg/pin and screws down basically the same way the cable would, except it has a harness connection on top.
OK then, just to be 100% sure, the picture you just posted is the original sensor that started you on this journey, and the picture in post 26 is a generic replacement that uses a screw-on adapter to make it an electronic sensor...
when I run the meter's black pin to negative on the battery, and red pin to the black/white (positive??) wire I get nothing
if I red pin to negative on battery and black pin to the black/white wire I then do get 12 volts.
This has me scratching my head a bit. When you put the meter black to the battery (-) you get nothing, positive or negative on the black/white wire but if you reverse the meter leads you get +12 volts?
I'm gona have to ponder on that a bit...
OK then, just to be 100% sure, the picture you just posted is the original sensor that started you on this journey, and the picture in post 26 is a generic replacement that uses a screw-on adapter to make it an electronic sensor...
This has me scratching my head a bit. When you put the meter black to the battery (-) you get nothing, positive or negative on the black/white wire but if you reverse the meter leads you get +12 volts?
I'm gona have to ponder on that a bit...
Correct. And yes the burned speed sensor is mine, and the gear in the pic is also. (it's back in the trans now) To my knowledge they are both original to the car from Nov. 1990.
And yeah, the wires being opposite from what everyone has said they should be is driving me mad. Maybe the first sensor's they came out with had the + and - prongs located differently... I have no idea but it doesn't make sense.
That's not what I'm pondering. You said the SAME WIRE gets nothing with the meter one way, but +12v just by switching the meter leads? Or did I read that wrong?
Black pin on negative battery post and red pin on black wire = 12v
Black pin on negative battery post and red pin on black/white wire= 0v
Black pin on negative battery post and red pin on yellow wire = 5v
Black pin on positive battery post and red pin on black/white wire = -12v
"with or without the fuse I get a ohm reading of 0.04 from the black/white (supposed to be + wire), same reading as if I touch the meter's pins together."
I just hooked up my test light. (just an old boost gauge with a 12v bulb and wires coming out of it for power)
I connected the light's positive yellow wire to the black wire, and the light's negative black wire to the black/white wire and the light lit up.
There is no doubt about it, the wires are opposite of how they should be. Unless someone seriously objects, it may come down to me just swapping the wires around and seeing what happens. I am out of ideas.
That was what I was about to post. What you think Steve?
Edit: got to go see you guys later.
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