FJ1100 ALTERNATOR DIED ,TRYING FJ1200 FIT UP

[Brian]

G'day fellow FJians , my 84 alternator died (i think) it shows no charge when meter plugged in to harness & battery losing charge ,I have bought a used 1200 alt but am having 3 problems;
1.   mounting oring not same so do i use 1100 or 1200 oring ? (as i got a bit of a leak) ?

2.  when meter plugged in to 1200 alt harness i can only get a reading of 2.0 at 4500rpm is that correct output value ?

3. when harness hooked up to battery, meter reads 12.5v ,but with engine running reading doesnt change ??

has anyone tried fitting a 1200 alt to a 1100 please.

cheers Brian

[movenon]

G'day fellow FJians , my 84 alternator died (i think) it shows no charge when meter plugged in to harness & battery losing charge ,I have bought a used 1200 alt but am having 3 problems;
1.   mounting oring not same so do i use 1100 or 1200 oring ? (as i got a bit of a leak) ?

2.  when meter plugged in to 1200 alt harness i can only get a reading of 2.0 at 4500rpm is that correct output value ?

3. when harness hooked up to battery, meter reads 12.5v ,but with engine running reading doesnt change ??

has anyone tried fitting a 1200 alt to a 1100 please.

cheers Brian

When you engine is running the output or voltage measured your battery should run from around 13 volts to a max of 15 volts.  I typically run around 14.2-14.9 volts but my battery is due to be replaced.

The brown wire as I read the diagram should be reading what ever the voltage is at your battery. Might be slightly less due to the fuses and connector but close to your battery voltage.  The red wire should read 13-15volts with the engine running.

You might check the brown wire. Trace it back to the fuse box and check the connections. As I understand it you are only getting 2 volts there ? Should be 12.5 +.

Someone else will have to address the interchangeability issue.  I am sure someone with more information will be on here soon.
George

[FJmonkey]

Are you measuring at idle RPMs (1100 RPM)? If so then you will not get a good reading. Pick the RPMs UP and measure again.... Like a cruzing speed (3000 RPM)...

[aviationfred]

The Alternator/Generator are 100% interchangeable between all years.

http://www.partzilla.com/parts/detail/yamaha/YP-2GH-81600-55-00.html

The 'O'-ring shows the same Part Number for the 84'-87' models.

http://www.partzilla.com/parts/detail/yamaha/YP-36Y-81642-50-00.html

Hope this helps some.

Fred

[Flying Scotsman]

1100 generator/alternator and the 1200 are different early ones had 2 bolts later had 3 bolts.
It will still fit and will work with just the top bolt in place.

[Arnie]

I seem to recall "Mazz" (David Mazzaferro) had this problem with the O-ring when changing alternators on his FJ.
Sorry, but I don't recall how he ended up curing the problem, but you can email him directly at   dlmazz@att.net
If you put FJ in the subject line he'll probably answer you. :-)  Say "hi" from me.
I don't think he ever joined this or the yahoo email group.

[racerrad8]

1) Do you have battery power at both wires with the key in the run position?
2) Have you inspected the plug to the alternator by unplugging it, they are know to look good on the outside and burned up on the inside.
3 The alternators did use different o-rings; one thick & one thin. and it was a year thing in the middle. It sounds like you are trying to put the thin o-ring onto the thick groove and it will not seal. The alternator will not fit into the block with the thick o-ring in the the groove.

Let us know on the power to the alternator which might be the issue why it is not charging.

Randy - RPM

[Brian]

HEY GENTS , Its all good the nd alternator was the problem not the bike I found another alternator off a 2002 J900 DIVERSION FITTED STRAIGHT IN JUST NEED LONGER BOLTS & charging at 14.5 just like a bought one , so thanks for all the test tipps im always up for learning something guys cheers