sleeperman

My uncle has a 95 3500 and the tach, speedometer, and the voltmeter are all not working and the alternator is not charging. Has any body had any problems like this and if so what didi you do about them. I checked all the fuses and all the connections and everything seems to be fine but they still do not work.

patdaly

Check engine speed sensor, front by the damper.

Also fuse #9 I believe.

Without a tach reference signal, it will not charge.

infidel

Figures 3 and 8 here may help http://www.tstproducts.com/DowelPina.pdf

Without a rpm signal the computer thinks the engine isn't running. Nothing electronic will work.
Make sure the wires running down the front of the engine are intact and the connector is clean. Check the sensor gap, a business card thickness works for me.
If all seems fine replace the sensor, availible at any autoparts store.

Swarthy Dago

95 2500 4X4: same exact problem last week. Thank you infidel, I was almost going to email you till I saw this thread. I also found a dead short on the circuit that runs the "horn and parking lamp".

skoalcowboi00

I chased this problem around for awhile on my 95 2500 5 speed. I replaced batteries, speed sensor, alt, checked all connections and tore the fuse box apart and cleaned it. It ended up being the PCM. It was very frustrating and left me stranded many a places until I figured it out.

ClassicTranspor

So after replacing / chasing the problem what was the solution? thx ct, for me, didnt read far enuff to see the pcm ws the problem, sorry

infidel

There is a fellow on another CTD website who has been chasing the same problem. Finally went to the dealer and they replaced the PCM.
Fixed the problem for about an hour, now they aren't sure at all what's going on.
Be careful throwing a $700 PCM at the problem.