HELPPPPPP..Speedo quit working

[Devil-Dog]

I drove my 95 Z28 camero with the LT1 motor and auto tranny to my girlfriends house about 20 miles away with cruise control locked on.Once i got there and shut it down,everything was fine. The next morning I stuck the key in it to start it up and noticed immediately,,,NO SPEEDOMETER and tranny wasnt shifting right,prior to last night,,,NO PROBLEMS WHATSOEVER. Put car in shop and was told it needed TWO sensors in the tranny that make the speedo work. OK,,,200.00 for these two NEW sensors or coils and still no speedo or shifting right. Then my machanic sugested a NEW PCM box. We ordered a rebuilt one from discount auto. NOW,,,,400.00 later for electical components and still NO speedo,NO criuse control and NO shifting right???? Now where do we look. My machanic has no clue left and we are out 400.00 in parts that the car didnt need. My girlfriend loves this car and we want the speedo,cruise control and tranny to shift like it did before this FREAK MISHAP. Any help would greatly be appreciated,,,signed DESPARATE

[89IROC&RS]

is the "shop" a dealership????

i used to do electrical diagnostics, and granted, its not always an exact science, but to go from some sensors, to a full blown pcm and then to be like... well shoot, i dunno whats wrong with it.

sounds kinda like hes not following a flow chart diagram to diagnose the problem. and is instead kinda shotgunning the problem.

as for whats really wrong with it.... the only thing i can think of that it might be, that he probly would have seen when he pulled the speed sensor, would be the speed sensor drive gear on the output shaft. they are plastic, and can break.

[Devil-Dog]

No my friend,,took to a DEALERSHIP today and they say its a BAD wire in the wiring harness,,,Now they say its not broken or burnt BUT,,,,its bad on a reading so they are adding JUST ONE WIRE to replace the bad wire and charging me 325.00 for fixing the wire.Thats why i hate DEALERSHIPS...One bad wire,replace with one wire added alongside of harness,,,PAY 325.00,,,Oh well,,at least its fixed this time I hope but thanks Sir for your help and input,,,Semper-Fi my friend and again,,thank you

[89IROC&RS]

sorry to hear the dealership gave you such a run around. id say the guy doing your diagnostics probly should be sticking with intake manifolds and oil changes. Or was in too much of a hurry. not all mechanics are worthy of the "technition" title. i know there were several guys at the dealership i worked at that we never gave electrical problems to, because they would replace the car before checking a wireing harness for a pinch. then there were guys like the guy i worked under, who i swear i saw move his hands over a wiring harness, and point to where the problem was, and it really was there. granted he had probly seen that particular problem 100 times and was just messing with me, but he was that good. with electrical problems guessing almost never fixes it, you have to find the point of failure. sounds to me like the guy who did your work didnt do that.

so again, sorry your experience was so bad.

[Devil-Dog]

Car is suppose to be ready by 5:00pm today,,,cross your fingers and 400.00 in components from my machanic and 325.00 from dealership,,,725.00 for a bad wire,,Dayummmm..lol anyway,,,I have a Sweet Original steel body 1928 Ford Tudor Sedan with a balanced & blue-printed FULL BLOWN chevy 350 all polished alum & chrome motor with only 19,900 ORIGINAL DAILY driven miles since TOTAL ground up restoration for sale or trade if you or anyone wants a very rare car,,I need a 4x4 or hummer,,Im asking 55,000.00 CASH or trade for equal value,,Car has won lots of throphies,,,pass the word around please...Need to get a truck to haul things and pull trailers,,,,Semper-Fi again and thanks for the quick replys and help

[Morley]

For future use.... The speedo is driven off of a vehicle speed sensor mounted on the side of the reans where the speedo cables used to go. This sensor feeds a signal to the speedo AND the PCM. It is a pulsed voltage signal and can be read with a meter. The PCM side of the signal is used for, among other things, shifting the trans.
It would take a little doing but you could tap into the sensor with a meter with long leads. Put the meter in the car and go for a drive, if the meter reads voltage, the sensor is good. If it reads nothing, sensor is bad.