Iltis Alternator Problems

[Rpoolie]

I just went through the same troubles (sporadic overcharging).
After checking all the grounds, finally removed the alternator and regulator and asked a local alt/gen repair shop to test.
Bottom line, after testing the reg was found to be faulty and was replaced, with no troubles since.
Cost was $140.00 taxes in.
The best advice to offer you is to send the unit to a repair shop for testing.
Would have saved me some time and frustration!