my tach and speedometer

my 1985 corvette rpm gauge stop working and my speedometer doesnt work my check engine soon light is on reads a code 24 wich means the veichle speed sensor is bad do u think thats why it dont work.  

online at

eautorepair.net  
or
alldatadiy.com

they have all the trouble shooting charts to follow those 3 or 4 problems...


the code 24 actually means the vech speed sensor circuit... something in it has failed or gone intermittent..   thats why there are flow charts...

there are also failures and dirty connections in the layers of circuit boards in digital dash boards...    there is at least one article on taking a digital dash board apart and resoldering the pins , cleaning  the contact pins and reassembling it..    it all depends upon how handy you are with car repairs and electronics repairs..

i wonder if the speedometer takes the speed sensor signal and processes it and sends a speed signal to the ECM...      as the ecm usually does not receive speed sensor data directly on these years...


i will take a peak at the wiring diagrams over at autozone.com... see if i can see anything..    they have free repair info that cover many years of vettes...  including years before 83 that the other places dont have...


yes... the speed sensor data is fed to the ecm from the dashboard...


you will need a static wrist strap... so you don't blow it up ...

here is the first page of an article...

http://www.corvettemagazine.com/1999/dec99/dash/dashp1.asp  

Where is the vech speed sensor located I replaced the sensor on the trans is that the same one ? on my dash all the lights are on and when i start it both the rpm and speed gauge jump then go back down to zero.I havent checked to see there power coming from the trans to the gauge.Thanks for all the help just bought the car and dont know much about it but im learning.Trying to stop speeding tickets.  

i would think that doing a little searching in the Tech section above...

or putting C4 into the search window above right might help with your learning..

were you able to copy and paste the link i posted into a new window and read the article???  it goes into the cluster deeply...

you might also choose to buy a printed version of the factory repair manual for it...  

there is a book store in riverside ca that sells used copys...  

http://www.faxonautoliterature.com/home_one.cfm

you are going to need a printed manual so you can service and repair you Corvette properly without making more problems...

this is a corvette... with technology at least one year ahead or more than other gm models....

just think... the 300+ horse power motors found in most chevy trucks have a great head design do to the corvette racing program...