Searching for 250YY short By neallyb (Read 1,425 times)

[neallyb]

Nothing makes me feel dumber than trying to find a short in automotive wiring. Symptoms are:

1) Dead battery after running for 20 or 30 miles.
2) Non working fuel gauge (after starting)
3) Non working temp gauge (after starting)
4) Sometime the temp gauge acts like a tachometer then goes to sleep

I took all the body panels off and carefully check every connection and ground. Could it be the instrument cluster itself? The manostat or CDI? They are all on that circuit.

Sigghh.

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[Bashan]

Hey, this guy comes packing with his own wiring diagram! You other guys listening up here? I'm, sure you're aware that manostat is the bizarre Chinese term for rectifier. So that wire is power to the CDI, I don't it would be involved in this. What puzzles me is that your battery is going dead which is another wire off of the rectifier. I'm wondering if your rectifier could be toast. What do you guys think? I'll probably get in trouble, I'm not supposed to post on the 250 board. Rich

[Cruiser]

Welcome to Scooter Doc, neallyb. It sounds like you have one or more poor connections and maybe one or more bad components in the charging system. I don't think any shorts are involved.

Now that you have the diagram, a multimeter is the most valuable tool for troubleshooting electrical problems. One area which is suspect is the connectors on the back side of the fuse box (also known as the disaster box) located next to the battery. The wire connectors that the fuses push into are sometimes not locked into the bottom of the fuse box and they have to be tightened and reseated. Here's a picture of the fuse box:



Replacing the fuses with American fuses is recommended for reliability.

The battery going dead after 20 to 30 minutes of operation could certainly be a bad R/R (manostat). It also could be bad connections at the R/R plugs, a bad connection at the blocking diode, or an open blocking diode. These problems would be easily determined with a multimeter. You should read at least 13.5 volts at idle (1800 rpm) going to at least 14.0 volts at 3 or 4000 rpm measured at the battery terminals.

[neallyb]

WOW - So much help! Just to make you all laugh... Since my first post, I checked every connection and ground on the bike from back to front. Frustrated, I even dismantled the instrument cluster today certain I would find a small gremlin living behind the tachometer who has chewed the wires.

Anyway, thanks for the wonderful support! I have just purchased a new multi-meter from the evil Walmart. So I now have a new tool and information to proceed - and will report back, especially now that I bookmarked this page.... thankee

[neallyb]

On a side note, I notice, last week when I got under the nose-cone there was evidence of wire "jickky-ing" as if it was tampered with and or repaired at the factory or more likely, the dealer... something I had hope to avoid buy purchasing new vehicle. Oh well.

[neallyb]

Need description of R/R plugs... don't know what that is.

[Bashan]

Sept 5, 2011 0:41:23 GMT -6 neallyb said:

Need description of R/R plugs... don't know what that is.

[/b][/quote]
The R/R is your rectifier/regulator which is the manostat on your diagram; plugs=connections. If need be I can dig up a pic of it or Cruiser has one. Let us know, Rich

[tvnacman]

what your decribing sounds like a bad alternator in a car , I would change the regulator , it is cheap enough . If that does not solve the problem you will have a good spare .

Second thought I would recheck the grounds and the battery terminals . here is a great way to check grounds (take a pig tail with a 100w bulb ) connect to the pos battery then touch the frame with the other wire, then touch the handle bars then the engine . A weak ground will read 0 ohms but put a load on it , then the ckt is dead . If you touch any of the thin wires in the harnes do it quick that 100w bulb will cook the harnes .

John

[neallyb]

Nah -- I can found it already. Like I said, I removed all body panels. So everything is easy to get to. I also checked the fuse box and all of the connections are all secure. Based upon the malfunctioning gauges - no change in apparent short...but one thing more is out of the way with your help. I also went ahead an replaced the fuses cause it's a cheap upgrade and I decided to order a replacement manostat. See attached pix. I'll keep in touch as to my progress. As my 250 is opened up now, I will be happy to provide any additional photos that may be of use to you and your readers.

ThankU for the help!. Neal

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[neallyb]

Hey thanks John - I've double checked the ground three times - even buffed all connectors and refastened to frame. I've removed the battery some many times I didn't think about the terminals or battery ground. I started carrying 2 batteries... one for the trip out. Then swapped them out for the trip home. Pretty silly when one wants to look hip and cool :-) Later friends - sitting this aside for now and going to a pool party as the temperature has dropped to a nice cool low 90's here. God bless the families struggling with wildfires central Texas.

[Bashan]

Sept 5, 2011 11:36:39 GMT -6 neallyb said:

I will be happy to provide any additional photos that may be of use to you and your readers.

[/b][/quote]
Yeah, pics are always welcome Neal, that's a good one of the fuse box. I'm going to snag that on my Photobucket as a reference picture. I ran across a picture of a rectifier when I was looking for something else. Rich

[Cruiser]

Here's a picture of the blocking diode, regulator/rectifier (R/R) and CDI from left to right:

[neallyb]

Whoa -!! I had those items mixed up! Thanks for posting the pix! Thanks again!

[Bashan]

THAT's the one I was looking for Cruiser. I snagged that one for my Photobucket album too. Rich