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Chevrolet Repair/Speed sensor called "cooked" . . . :)

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Enlarged view of speed sensor port.
Enlarged view of speed  

Wider view of on-vehicle speed sensor.
Wider view of on-vehic  
Hello, Tom,

Thank you for your latest answer.

I left something at class last night, so I went back to get it today.

When there, I talked to a couple of people, including one instructor.  After showing the photo of the close-up of the speed sensor port, he said that the sensor was ďcooked.Ē  Thus, it should, apparently, be replaced.

Iíll attach a picture of it.

I noticed Ė and pointed out Ė that there was a black area at the right side of the sensor port.  This was the same area where the teacher had noticed what she thought was plastic.  

My assumption or theory Ė is that (maybe) this occurred when the pigtail connector was working itself loose (by the way, that old connector only had one of the side clips, per what I saw yesterday), thus creating an arc.  

Anyway, if an arc DID occur, that would explain the (melted) plastic in that area, which, I assume, would have come from the old pigtail connector itself.

The thing to do indeed seems to be to replace the sensor, as you mentioned.

Since I have no lift on which to raise the car, though, that is a practical problem.

However, the other person at the school mentioned that I could use jack stands (which I donít have and donít have much room to store).  I could do that.

(A note: At first, Iíd thought that it wouldnít make sense that the speed sensor was out of order, because the speedometer seemed to be working perfectly, UNTIL, apparently, the wiring came loose Ė however, if the loosening of the wiring caused an arc that damaged the sensorís ability to work, then it could explain why both the connector and the sensor would be in need of replacement.)

About the shrink tubing: I donít know, but wouldnít that normally be placed over the wires BEFORE they are attached together?  Otherwise, Iíll have to cut a length of it lengthwise, so that it will fit over the already spliced-together wires, isnít that right?

Do you have any suggestions as to how long the shrink tubing should be?  I feel two inches would be long enough: Does that jibe with what you feel is the right length or minimum length?

Thanks again for your help.  If you have any feedback beyond what Iíve asked about here, please feel free to inform me of it.

(Iíll also attach a picture showing more of the sensor: It is an uncropped version of the same picture that I mentioned here that shows the enlarged view of the speed-sensor port.)

Best regards,

-- George

Answer
HI GEORGE, YES YOU ARE CORRECT, THAT SPEED SENSOR IS COOKED.  AND YES YOU ARE CORRECT AGAIN, THIS IS PROBABLY WHAT HAPPENED.  THE HARNESS CLIP GOT CORRODED AND THERE WAS A LOT OF ARCING INSIDE OF THE HARNESS WHICH RUINED THE HARNESS AND SPEED SENSOR. AND YES AGAIN, YOU ARE CORRECT THAT YOU WILL NEED TO CUT THE WIRING THAT YOUR TEACHER AND YOU SPLICED TOGETHER WITHOUT PUTTING THE SHRINK TUBING OVER THE WIRE.  THIS HAS TO GO ON THE WIRES BEFORE YOU SPLICE THEM TOGETHER.  AND I LIKE TO SEE 3 INCHES BARE MINIMUM OF SHRINK TUBING, THIS WILL COVER THE BUTT CONNECTOR AND RUN UP THE WIRE TO SEAL CORRECTLY.  IT SOUNDS TO ME LIKE YOU HAVE ISOLATED THE PROBLEM AND THE CAUSE AND I THINK AFTER YOU TAKE CARE OF THIS, EVERYTHING SHOULD BE A-OK.  
AGAIN, IF YOU HAVE ANY MORE PROBLEMS WITH THIS, FEEL FREE TO GET BACK TO ME.
- TOM

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PLEASE READ ALL OF THIS BEFORE ASKING ANY QUESTIONS. IF THIS CHEVY SECTION IS MAXED OUT.YOU CAN REACH ME IN THE OLDS/BUICK SECTION. Will answer questions from 6:00am to 10:00pm all days [EST][[[ NO DIESEL OR PAINT QUESTIONS]]] will answer all 1965 to present QUESTIONS ON ALL GM'S on mechanics of these cars. Keep in mind i am not there in person i am going on what you are telling me !! PLEASE IF ASKING A QUESTION GIVE ME AS MUCH INFO AS POSSIBLE. THE MORE THE BETTER. SUCH AS YEAR,MAKE,MODEL,ENGINE SIZE. THIS WILL HELP ME HELP YOU. I will not be able to answer all questions because of some situations that i would really need to be there and see things for myself,such as electrical issues. In many cases i would need wiring diagrams. I can also give you an estimate on what the cost would be at our repair shop as an idea to help you. Keep in mind that my answer is ONLY MY ADVICE,ck with your mechanic as well.. >> THANK YOU, TOM..

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I have been a ASE certified master mechanic for over 30 years and certified IN ALL 8 CATEGORIES,[engine repair,engine performance,auto trans,manual trans,clutches,steering and suspension,brakes,electrical systems,heating and air/cond. I am also a state CERTIFIED inspector for over 30 years. I do computer work [pcm]fault codes,pcm flashing,state inspection monitor readiness,repairs on exhaust,fuel service,[injection and carburetor,] charging system problems, running issues,alignments,frame problems,tire balance,struts and of course standard and anti-lock brakes.

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