9 relay was out. On those old REL's, if you get low exciter brushes you need to pull the 40 amp fuses and make sure your polarity is correct BEFORE you apply the DC back to the controller after you change the brushes and you crank the gen...... or you will do some damage.
So True..You can get them back in polarity with a dry cell battery on the exckiter fields when it 1st cranks up, or for that truly adventurous type, you can take 2 orange sticks lift off 2 adjacent brushes from the exciter commutator while the exciter is turning and let them pop down on the exciter simultaneously. Arcs a litte, but more times successful than not.
As for cleaner...
Back in the day the companies used this god awful motor cleaner with the generic name of SS25. It would clean the hell out of a motor, but is a known carcinogen. Of course we knew nothing of that and just used it. I'm talking 1 gallon pump sprayers of the stuff and wash down Generators and Motors.
Evidently it's still being made..
http://www.chemsearch.in.th/th/Product%20Lable/ss-25%20label.pdfAnyway we had a generator that would keep grounding out, and the company instead of pulling the genreator just sent the mechanic up with a gallon pump sprayer of SS25 and had him wash it out. This went on for about a year, until the mechanic.."ACCIDENTLY" filled up the pump sprayer with Varsol instead of SS25. Made a nice bon fire..