What exactly is this part and is what it's doing normal?

All the work you do in the workshop. Maintenance, repair, troubleshooting, customizing, etc.
Post Reply
User avatar
ddxxe
New to XJR
New to XJR
Posts: 6
Joined: Mon Apr 11, 2016 9:26 pm
Region or State: Oregon
Motorcycles Owned Currently: 1995 Seca II

What exactly is this part and is what it's doing normal?

Post by ddxxe » Wed Jun 07, 2017 9:31 pm

What is the silver unit with the cooling fins on it? And should it be getting so hot that I can barely touch it? It's not glowing red but definitely you can't place your hand on it longer than 4 seconds before it becomes unbearably painful. I'm worried that its grounding out on something that it shouldn't or if that's normal for it to get warm hence the cooling fins and I can just ignore it?
Image
Straßenkämpfer

Crimson
One of the Regulars
One of the Regulars
Posts: 101
Joined: Mon May 01, 2017 9:58 am
Region or State: London
Motorcycles Owned Currently: XJ600S
Contact:

Re: What exactly is this part and is what it's doing normal?

Post by Crimson » Thu Jun 08, 2017 8:21 am

It's a reg rec unit. It's crap. Remove it, bin it and replace it with a MOSFET reg rec immediately. All it is, is a set of diodes to half-wave or full-wave rectify the current from the alternator to the battery, so that (in theory) there is no current going back along it, and there are no power surges or voltage spikes.

Mine failed when it got hot, and it took out my battery along with it. Turned out to be more expensive (as I then had to replace both the reg rec and the battery) but was also potentially dangerous, as the battery overcharged and began boiling. Take the heat from that thing as a warning sign, and bin it!

A blow-by-blow account of what happened with mine:
viewtopic.php?f=127&t=8996

User avatar
Casper
Forum Moderator
Forum Moderator
Posts: 2312
Joined: Sun Feb 26, 2012 2:16 am
Region or State: Motor City (MI)
Motorcycles Owned Currently: 1994 XJ600, 2006 SV650

Re: What exactly is this part and is what it's doing normal?

Post by Casper » Thu Jun 08, 2017 8:47 am

(I cannot see your picture right now, my fault, so I will answer based on Crimson's post and your description.)

Regulator Rectifiers do produce heat.

Three diagnostic things to look for:
Voltage at battery higher than 15 V at 3000 RPM. (Regulator failed)
Voltage at battery not higher than battery voltage at 3000 RPM (Possible open failure, no charging)
Connector overheating and melting (usually due to higher power draw than charging system is designed to handle)

They are fairly cheap at around $50 and are easy to replace, but make sure yours is bad before throwing it out.
Men do not quit playing because they grow old; they grow old because they quit playing.

User avatar
ddxxe
New to XJR
New to XJR
Posts: 6
Joined: Mon Apr 11, 2016 9:26 pm
Region or State: Oregon
Motorcycles Owned Currently: 1995 Seca II

Re: What exactly is this part and is what it's doing normal?

Post by ddxxe » Thu Jun 08, 2017 10:46 am

Alrighty then! I have no problem replacing it. I'd rather replace just the rec than it plus the battery. I will test it out first with a volt meter but I'm assuming its shot. Thanks boys.
Straßenkämpfer

User avatar
ddxxe
New to XJR
New to XJR
Posts: 6
Joined: Mon Apr 11, 2016 9:26 pm
Region or State: Oregon
Motorcycles Owned Currently: 1995 Seca II

Re: What exactly is this part and is what it's doing normal?

Post by ddxxe » Thu Jun 08, 2017 9:03 pm

To replace it would I just get another Seca 2 used replacement? Or is there another reg/rec that's meant for another bike but just so happens to fit the Seca and is an upgrade like say from an R6? If someone could link me a serviceable universal one that would be awesome.

Also I just came back in from the garage. Put the multimeter on it, pulled the choke out (figured that would put me close to my 3k rpm) and I was putting up a solid 11.55 volts. Very consistent 11.55v at the battery. So I'm beginning to wonder if the reg/rec is operating at an acceptable temperature and I just have never noticed it till now and I'm being paranoid?
Straßenkämpfer

Crimson
One of the Regulars
One of the Regulars
Posts: 101
Joined: Mon May 01, 2017 9:58 am
Region or State: London
Motorcycles Owned Currently: XJ600S
Contact:

Re: What exactly is this part and is what it's doing normal?

Post by Crimson » Fri Jun 09, 2017 9:49 am

11.5V sounds a bit low. I would first check that your battery is charging. This would show that your alternator is in good shape. With the reg rec connected normally, if you blip the throttle while idling, the readout on your multimeter should change. You should see it increasing in voltage slightly even when idling, and more noticeably when you rev it a little.
When I fitted a new reg rec to mine, the first thing I noticed was that the voltage reading across the battery seemed very stable when idling. I didn't think there was anything wrong, so I took it for a ride, and the battery went flat after a couple of starts. This was because I hadn't earthed the new reg rec properly. So with a working reg rec properly fitted, the numbers should be changing on your multimeter as the battery charges, but they shouldn't ever exceed 15V at any revs. If they do, just turn off the bike and stop using it until you've got the new reg rec. However, even if they don't, it doesn't necessarily mean your reg rec is OK.
You can bench test your reg rec using some online instructions (e.g. http://www.ebay.com/gds/How-to-Test-a-R ... 231/g.html). When mine went bad, it had continuity in both directions along the white wires.

User avatar
Casper
Forum Moderator
Forum Moderator
Posts: 2312
Joined: Sun Feb 26, 2012 2:16 am
Region or State: Motor City (MI)
Motorcycles Owned Currently: 1994 XJ600, 2006 SV650

Re: What exactly is this part and is what it's doing normal?

Post by Casper » Fri Jun 09, 2017 1:26 pm

Choke shouldn't be enough to get 3000 RPM.

Have a buddy help you read the multimeter while you rev the bike.

When I replaced mine, I just got an OEM replacement.
Men do not quit playing because they grow old; they grow old because they quit playing.

Post Reply

Who is online

Users browsing this forum: No registered users