I posted this problem before and thought I had it fixed. the error code 41 has returned.

Now it seems the trouble light comes opn sometimes when I start the engine. (BTW it is a 4.0L) If the light comes on I can switch the key off and back on again and the light goes out most of the time. sometimes it takes a couple of trys to get the light off. Once the light is off I can run it without any problems. Had the battery and alternator checked by autozone and replaced the battery. Alternator checked fine with their equipment. Error code 41 talkes about an alternator field relay but I have been unable to find one. All of the relays and fuses in the distribution box checks fine. Does the ECU or alternator have a relay in them? Anyone have any suggestions as to where to check? Thanks Don

 

I bet all it is prolly a lose wire somewhere or something little like that!!

 

The Tan/Green wire from the alternator to the gauge on the dash passes through a 15 ohmn resistor wire, if the wire is frayed or corroaded the alternator output circuit will be lower than needed to maintain battery and acessories. Will cause the field circuit to open and close to quickly for the primative ecu that your truck has. Other than that I can't think of anything right now, but if I do you'll be sure to know.

 

My vehicle does not have any meters (Yet). I only have idiot lights. Is there a relay anywhere in the ecm or alternator? Quickly switching the ignition off and on again seems to reset something. Don

 

the tan/green wire goes to the idiot light, I miss stated before

 

The symtoms do not seem to match. If it was an intermittant connection it should happen while driving. The only time the check engine light comes on (with error 41) is during the starting of the engine, some of the time. It never comes on after starting and running for a bit. And when it does come on right after starting, all I have to do is shut it off momentarily and back on. I can even do it while driving. The engine does not have to come to a complete stop. Sounds more like a relay that does not pull in some of the time. But where might the relay be located? Thanks Don