What causes the "check engine" light to come on? I've had my truck since new and this morning that light came on.
I could here an engine. I got out and checked it. It was still there?
Why would the light come on?
The only thing that was odd was the volts were reading above 14. Also my satelite receiver quit working.
I pulled over, turned off the engine and the satelite receiver started working again.
I thought maybe the alternator wasn't sensing battery voltage so I cleaned the terminals and started back up. Light was off and receiver worked but volt meter still read over 14.
Any thoughts? Please? This is the original alternator. Are they regulated internaly?
Thanks in advance,

Peter

 

The alt is regulated by the computor , I also have a 94 so there isn't much to that system , lucky , some to the new stuff has a couple hundred codes , and you can multiply the causes of the codes by 3 at least , so on the newer trucks its not as simple as ours.
Keep the sat. disconnected till you have the problum fixed , and watch for the batteries boiling over from over charging , wash off with water to avoid other damage from that.
How old are the batteries ? it could be that one is bad and the charging system is good and just over charging becouse of a bad cell or more , have the batteries load tested indipenditly .