Hey all, I have a 1992 cummins w. an auto 2 wheel drive. I believe it to be the a518? Am i Correct? But anyways, the speedometer jumps around, the check engine light will flicker and the volt gauge will flicker around too and overdrive wasnt working so I searched the forums found the VSS problem. So I got a new VSS installed it and it still is all the same. SO next i take the resistance of the 2 wires leading to the VSS. It was 1280 ohms, seems a bit high to me. I checked the wires they all look okay. My idea was just to jumper out the solenoid for overdrive but then there is still the flashing check engine light (when i say flashing i mean flickering it isnt like it is reading a code out). I still have to check the TPS but i doubt it could cause the charging problem. What si weird is that the gauge bounces around (volt gauge) but the battery still charges. My volt meter shows 13.83 volts on idle right after start up so the alternator does work. Im stumped guys, any help would be fantastic
And by the way you guys run an excellent forum, this has become my new home page

 

Does other pcm controlled stuff work on your truck like the grid heaters,AC,Cruse control? and does your voltmeter give you a stable reading when you rev the engine. You may have a problem with your voltage regulator or you pcm may be going out.

 

Cruise control kicks off when it kicks out of OD I will try revvin it today and checkin the voltage. How much would a PCM run me? That sounds expensive.

 

Pcm would cost about 200.00

http://www.autopart.com/ecc/ECC1992DODGEW250PICKUP.htm

 

Before you replace the PCM, unplug the connectors from it and look them over real good for corrosion.

 

I dont want to replace the PCM till Im sure it is the PCM. Is there anyway to isolate the problem to it?

Thanks a bunch guys for all your help.

 

Here's some basic stuff you can check:

https://www.dieseltruckresource.com/...18&postcount=4