| Author | Message | ||
| Darrell Black, DVM (Darrelldvm)
Registered Member Username: Darrelldvm Post Number: 57 Registered: 6-2005 Posted From: 72.4.181.208 Rating: N/A |
A little recapitulation: I had torn diode wires in my 50DN generator on my 4106. I ordered relpacement diodes from BUS SERVICE INC. out of Kansas. I installed the new diodes & the generator did not work. I tore back into the generator & removed the NEW diodes. I found out that I was sent the WRONG diodes. I was sent POSITIVE diodes & the oil cooled 50DN uses NEGATIVE diodes. The question was whether any damaged occured to the generator running with the wrong diodes.(It didn't work.) I installed the NEG diodes today and BINGO it works!!! I have no idea why John at BUS SERVICES sent positive diodes. I talked to several Diesel electric service companies & they all said they never sell poitive diodes for an oil cooled 55DN. I guess I should have checked the schematic diode symbol on the old & new diodes to confirm they were in the same direction. All works now. Thanks to all the helpers. Darrell | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 1040 Registered: 1-2003 Posted From: 67.142.130.16  Rating: N/A |
Actually, Darrell, the alternator is made in both versions, positive and negative. It's likely they've never sold any, just because positive-ground is very uncommon, but there is a reason the diodes come in both flavors. Glad to hear it is all working now that you have the correct parts. -Sean http://OurOdyssey.BlogSpot.com | ||
| Tony LEE (T_lee)
Registered Member Username: T_lee Post Number: 70 Registered: 11-2007 Posted From: 64.134.228.35 Rating: N/A |
Having pulled mine apart a couple of times I should have a clearer mental image of the diode arrangement but I assumed there were three of each polarity. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 1052 Registered: 1-2003 Posted From: 72.171.0.142 Rating: N/A |
Tony, All six are identical. Three thread into the alternator frame itself ("ground") and their leads attach to the three "diode supports" that attach to the stator studs. The other three thread into the diode supports, and their leads come together at the output terminal. -Sean http://OurOdyssey.BlogSpot.com | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 972 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Tony, You're right. Apparently Darrel's supplier sent him 3 of the wrong ones. I think they would have burned immediately had he not had a diode type battery seperator. I know of another bus that lost all six, plus the voltage regulator, when new batteries were installed backwards after the coach had sat for several years. G | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 1054 Registered: 1-2003 Posted From: 67.142.130.45 Rating: N/A |
George, All six diodes on the 50DN are identical, there are not two different polarities. It has to do with the way they are designed to be installed. Also, as I wrote in the other thread, if only three are wrong, and they are either the upper or lower three, nothing will break, but the alternator will not produce any output. If all six are wrong, then the alternator will become a positive-ground unit. Since he replaced only the upper three with the wrong ones, he just go no output. The isolator was not a factor here (but would have been had all six diodes been incorrect). -Sean http://OurOdyssey.BlogSpot.com |