Seneca 37FS check engine light - charging issues

[Clayduster71]

Why traveling across country this week my 2012 Seneca started throwing up a check engine light. I did not think too much of it the first time it happened because it went right out, but then it started doing it again. It just so happens I was driving early in the morning on I-40 and I noticed the headlights getting very bright. About that time the check engine light came on. I noticed the gauge said the alternator was charging at 16.7 volts (which is WAY too high) It did this several times before the freightliner dealer opened up at 8am.

The service guy at freightliner knew exactly what it was. My alternator voltage regulator was going bad. He said if I didn't replace the alternator it would eventually fry my ECM. Luckily, the freighliner place in Nashville had one on the shelf. They charged me $280 for it. They didn't have time to put it on, so I decided to put it on myself while heading up I-24.

Let me tell you guys something, if you have to change out your alternator make darn well sure you do it at a truck stop that has a shop. I had no problems taking it off, it's only held on by 4 bolts. The issue is the serpentine pulley - it's not included. You have to take off the old one and reuse it. You'll NEVER get that bolt loose or get that pulley off without a impact wrench and a pulley puller. Thank GOD i decided to change it out at a Loves truck stop. Those guys saved the day!

After they got the pulley off, I installed the new alternator. Charging issue solved!

Alan