Alternator sparks?

[jt20]

I know they often spark inside.. just electricity in and around the brushes; but why would they spark outside the aramture? ANd is this dangerous with ehaust fumes in the engine bay?

[bustedbenz]

Originally Posted by jt20

I know they often spark inside.. just electricity in and around the brushes; but why would they spark outside the aramture? ANd is this dangerous with ehaust fumes in the engine bay?

Diesel fumes aren't particularly explosive, unlike gasoline fumes... but it's probably still something that shouldn't be happening.

One of the electricians will know why.

[rrgrassi]

Check your brushes and armature. If the copper braid is contacting other things, you can see sparks in other places.

[jt20]

There was a nut in the rear section bouncing around !!

[hey_allen]

My SEC's alternator had the inner bearing cage of the rear bearing wandering around the rear of the alternator.

No undue noise from the bearings, and the only indication I had that something was wrong was when it turned on all the dash warning lights, as well as the fuel tank empty light for one minute, before going back to normal operation. Pulling the brush holder to check the brush condition, I found the bearing cage leaning against the commutator rings.

When I split the case to figure out what was going on, all the little balls fell out on the workbench!