Hi all, I have a 2011 550 with a 6.7 which has developed an electrical issue.
Driving on highway with no warning the dash light started to go on and off then the fan, which was off, went on and off at high speed. no motor issues,i.e. stalling. Battery light came on and check brake system in message center.
Checked and replaced both batteries ( one was dead ). Acc Bat was dead.
Found code P0625/ generator field /f terminal circuit low. tested primary alt. and its ok. Battery light still on. Going to test 2nd alt.
Anybody run across any of this ,truck has 30k
Thanks

 

I don't recall reading anything with all your issues but it does sound like you've eliminated the easy stuff.

You have fresh batts and both alts work properly?

Check the voltage regulator if there is one....

Also, there is the possibility of a chaffed wire somewhere causing issues like this. There are a couple of folks here that have had experience fixing this. I believe it's under the main power dist box somewhere.

 

im getting second alt tested in morning and if thats ok then i guess im back to belly crawling looking at wires some more.
thanks

 

I recall a TSB about a chafed wire on 2011's near left front tire, near top of wheel well.
I'll see if I can find it.

Cant find anything, but if you do a search for "chaffed wires" there are several.

 

Thanks I will look that up , the 2nd alt tested fine but the light stays on. The mini max says it clears the code but it pops right back up. Am back to wires and having someone else try to remove the code.
Thanks again

 

Anyone one have an out come on this?