News:

         
Welcome to FJowners.com


It is the members who make this best place for FJ related content on the internet.

Main Menu

Alternator Maybe?

Started by Greg C, June 16, 2018, 06:34:50 PM

Previous topic - Next topic

Greg C

Hello Everyone!

I'd like to say THANK YOU in advance as I really appreciate your help as I have benefited from your experience numerous times during my latest FJ escapade.

Today I was out for a ride with my father. We rode about 40 miles and we stopped to take in a view. I smelled something that kind of faintly smelled like burning rubber and did a once over on the bike and saw nothing. We stopped for lunch a few miles down the road. No problems. We left, went about a mile and the FJ died in the middle of the road ( a damn busy road I must say). No power at all. My dad rode home and came back with a trailer. After a hairy drive back (the trailer was rickety and barely big enough) we discovered the alternator wasn't charging at all. I have three questions:

Has anyone ever had a similar experience?

Is there somewhere that I can get a rebuild kit?

Or should I just go with a new RPM alternator?

Battery is a brand new lithium ion battery. Tests good.
Greg
1990 FJ1200
Previous Bikes
1992 FJ1200
1983 GL650
1982 CB650
1980 CB750
1978 KZ200 (first bike)

Pat Conlon

Sorry to hear of your troubles Greg.
It's certainly a buzz kill to have that happen in the middle of a Saturday ride.

Before you start replacing (expensive) parts....A couple of Q's:
Why do you think the generator is bad? Yes, the bike ran off the battery until the battery was exhausted, then the bike died, but the culprit could be something other than the generator.
Could the smell you noticed be from a cooked wire? Do you have a service manual? There are diagnostic tests you can perform. Did you check the generator output at the poles on the generator to confirm that there is no output?
Did you ohm check the generator output red supply wire and the brown field (sensing) wire?
Battery connections good? Loose connections can arc producing the smell you noticed.

Don't be discouraged.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

racerrad8

Start with the basics; check the red alternator plug. Pull it apart and inspect for signs of overheating/melting.

Sorry, not at the shop to be able to attach a photo of a melted one.

If the plug is melted, it needs to be replaced/bypassed.

If the plug is good, you need to check voltage for battery voltage on both wires of the bike side plug with the key on. If there is not battery voltage at either wire, that is where the diagnosis needs to begin.

Randy - RPM
Randy - RPM

FJmonkey

Looks good Eh?



Look inside...


The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

Greg C

Thank You! I only checked the voltage with it running at the battery terminals and there was nothing coming to the battery. I do have a manual and I'll do what you mentioned above before replace anything.


Quote from: Pat Conlon on June 16, 2018, 07:30:28 PM
Sorry to hear of your troubles Greg.
It's certainly a buzz kill to have that happen in the middle of a Saturday ride.

Before you start replacing (expensive) parts....A couple of Q's:
Why do you think the generator is bad? Yes, the bike ran off the battery until the battery was exhausted, then the bike died, but the culprit could be something other than the generator.
Could the smell you noticed be from a cooked wire? Do you have a service manual? There are diagnostic tests you can perform. Did you check the generator output at the poles on the generator to confirm that there is no output?
Did you ohm check the generator output red supply wire and the brown field (sensing) wire?
Battery connections good? Loose connections can arc producing the smell you noticed.



Don't be discouraged.

1990 FJ1200
Previous Bikes
1992 FJ1200
1983 GL650
1982 CB650
1980 CB750
1978 KZ200 (first bike)

Greg C

Thank you Randy! I'll start there. You guys are all pretty darn awesome!

Quote from: FJmonkey on June 16, 2018, 10:30:56 PM
Looks good Eh?



Look inside...



1990 FJ1200
Previous Bikes
1992 FJ1200
1983 GL650
1982 CB650
1980 CB750
1978 KZ200 (first bike)

racerrad8

Thank you and thanks to monkey for posting up pictures.

Randy - RPM
Randy - RPM

Greg C

Here's an update:

I ended up isolating it to the alternator. When I opened it up I noticed that the brushes were stuck and the brush assembly was melted. I'll attach the pictures. I checked the stator coil and it was in spec, but the field coil seems to be out of spec. Based on what I could see in the manual in terms of testing it (I think I had my meter leads in the right place). I was getting nothing (spec is 4 ohms + or - 5%. I didn't remove it from the case as shown in the image in the manual, but the manual directions only say to remove the brush assembly.

I put it all back together and noticed that I was able to fit a .007 feeler gauge in-between the brushes and the shaft.

Do you think the brushes arced and fried the field coil or the other way around?

Thanks,

Greg


Quote from: Greg C on June 16, 2018, 06:34:50 PM
Hello Everyone!

I'd like to say THANK YOU in advance as I really appreciate your help as I have benefited from your experience numerous times during my latest FJ escapade.

Today I was out for a ride with my father. We rode about 40 miles and we stopped to take in a view. I smelled something that kind of faintly smelled like burning rubber and did a once over on the bike and saw nothing. We stopped for lunch a few miles down the road. No problems. We left, went about a mile and the FJ died in the middle of the road ( a damn busy road I must say). No power at all. My dad rode home and came back with a trailer. After a hairy drive back (the trailer was rickety and barely big enough) we discovered the alternator wasn't charging at all. I have three questions:

Has anyone ever had a similar experience?

Is there somewhere that I can get a rebuild kit?

Or should I just go with a new RPM alternator?

Battery is a brand new lithium ion battery. Tests good.
Greg
1990 FJ1200
Previous Bikes
1992 FJ1200
1983 GL650
1982 CB650
1980 CB750
1978 KZ200 (first bike)