Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Bob & Sue on February 28, 2016, 02:15:58 pm

Title: Reversed alternator connections.
Post by: Bob & Sue on February 28, 2016, 02:15:58 pm
While having some work done at a Fortravel (w/ Motorcade discount) recommended shop it seems they installed an alternator and hooked up the connections " backwards".  I was told that they had probably " blown" the voltage regulator part of it. Without knowing just which wires exactly were reversed, I'm wondering what else could have been damaged.

 The shop has a very good reputation and has several high end coaches in their bays with a variety of things being done to them. I do trust them to do exactly what's necessary for repairs. They have also completed a cooling system flush w/ new long life coolant , replaced the hour meter on the generator and replaced an aging engine battery ( part of the effort to solv the charging problem).

 The problem happened on Friday afternoon, so a new alternator was ordered and could be installed as soon as Monday or could take as long as Wednesday we were told.

  Has anybody else ever done anything like this ?    Thanks for any imput.
Title: Re: Reversed alternator connections.
Post by: craneman on February 28, 2016, 02:35:54 pm
The only wires they could have crossed are the small ones to the voltage regulator, don't see how it could cause any coach damage.
Title: Re: Reversed alternator connections.
Post by: Bob & Sue on February 28, 2016, 02:52:08 pm
The only wires they could have crossed are the small ones to the voltage regulator, don't see how it could cause any coach damage.


That's great to hear !!  Thanks much.

 Gotta love this forum for quick answers.
Title: Re: Reversed alternator connections.
Post by: Geoffh on February 28, 2016, 04:57:55 pm
Hi Bob,
 Did they fry the connections on the alternator? When I burnt mine out ( don't ask ) it was quite a while later I found that the isolator had taken some heat and so I bought one from O'Reillys and replaced that also. I hope this is not the case for yours.
Geoffh
Title: Re: Reversed alternator connections.
Post by: Gary Bouland (RIP) on February 29, 2016, 08:23:38 am
Reversed connections probably fried the diodes.  Depends on what Alternator you have,  GM or Delco types are easily fried this way.
Gary B
Title: Re: Reversed alternator connections.
Post by: Bob & Sue on March 01, 2016, 12:59:38 pm
Geoff.
 What was the symptom that indicated the isolated was damaged. Not sure what to look for.

Gary.
  We will pick up the coach today. All I know so far is that the alternator that was in it was not a Leece Neville (sp) and the new one came from NAPA. I was told that the one they fried on Friday had an extra terminal. Seems the installer wasn't sure about the connections obviously. Monday they had " a fresh set of eyes" on the project and " working fine now".

    ARGH  Motor homes are so much different than a convential vehicle in the parts and repair aspect and I'm still trying to get my head around it.
Title: Re: Reversed alternator connections.
Post by: Gary Bouland (RIP) on March 01, 2016, 05:35:37 pm
Bob, VERY IMPORTANT that the shop understand that FT's have FOUR wire EXTERNALLY excited systems.  If they try to install another type it will not work.  Do a search here and read all you can about the alternator systems on FT's.  Most shops do not have a clue about four wire systems and isolators.  Good luck with it.  I do not recall when I looked at that coach that it had anything other than a Leece Neville or a OEM alternator.
Gary B
Title: Re: Reversed alternator connections.
Post by: John44 on March 01, 2016, 05:50:20 pm
Thats what I'm trying to determine with my post,my alternator was working great with 3 wires,are you counting the black wire
from the voltage reg to the terminal on the left as the 4th wire,on my coach the thats how it was wired but the so called left
terminal did not have any other wire going to it,just the one from the regulator.
Title: Re: Reversed alternator connections.
Post by: Geoffh on March 02, 2016, 01:05:15 am
Hi Bob,
 After having the alternator rebuilt, I did have problems with the coach batteries losing their charge, going through different possibilities with my brother, John would suggest I check this then that and one time I inspected the isolator and saw that it had been subjected to a power surge, which had to have been the occasion  I fried my alternator. ( see photo, it shows the discolouration from excessive heat ). I have replaced the unit and things are good again.
wishing you good luck with your repairs,
GeoffH
Title: Re: Reversed alternator connections.
Post by: FourTravelers on March 02, 2016, 03:01:32 am
Bob
Was your alternator a Powerline 24HD /  190 amp?