I've had a check engine light off and on since putting on a new gas cap. Scanned and no trouble code so had it cleared. About a month later it started up again and code for evap system but found no problems. Today the wife gave her brother a jump start and now have an off and on check gauge light and voltage spike. I know the voltage regulator is part of the ECM/PCM but should I have the alternator checked first and should it be on or off the vehicle? And if it is the PCM, would it be worthwhile to try to find a matching truck being parted? Money is real tight since I got hurt and have been out of work for almost 4 months. I know there are many on here with much more knowledge/experience than me as I was a member before and so I turn to you guys. Thanks in advance.

 

If you suspect the alternator, pull it off and take it to AZ or Oreileys or somewhere. They can test it. If it fails (watch while they are doing it) have them test it a second time.

If the CEL is on, there is a code. Need a reader that can read stored codes. You can pull negative cable off battery for a few minutes and put it back on to clear if you need to.

There is a service manual tha you can download in the FAQ/DIY section.

Also, if you put your truck info in your sigature (go to "User CP" above) it will accomplish 2 things. 1) everyone will know what model truck you are havng a problem with such as year, engine, trans, etc. and 2) it will keep zman from getting onto you for not having your info in your signature!

Welcome to DF.

 

Thanks for the info. I did forget. Been running between garage and computer.

 

Thanks for the welcome. Cleared the CEL and hopefully will stay off. Made sure connections to PCM/PCM were clean/tight. Will drive to church tomorrow and see what happens.

 

If it comes back, follow up with the problem and someone will have more ideas.

 

Drove several miles with speeds from 25 mph to 50 mph, stop and go and idled for about 10 min. So far nothing. Hopefully if it does it again I will be near an auto parts store. Thanks and good to be back.