16 gauge is good for most bike wiring. Yamaha used mostly 18 gauge, which is acceptable but its not the best.
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Stella - 1977D survivor, back on the road.
DanielBlack
XS650 Junkie
Ok, thank you. That's what I thought.
I'll be honest, I'm not sure of my next step.
Plug stuff in, new rectifier, fire her up, follow voltages? With other components probably good what else might fry the neg side rectifier diodes?
I'll be honest, I'm not sure of my next step.
Plug stuff in, new rectifier, fire her up, follow voltages? With other components probably good what else might fry the neg side rectifier diodes?
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Another member reported rectifier failure, of that compact import model, preceeded by a hot spot on one side. Anybody remember that thread?
Going out on a limb here, I wonder if this rectifier's construction has each of its 3 diodes built on a common die, one for the pos, one for the neg. With a process flaw, all 3 diodes on a die would likely fail.
Would have to cut one apart to see.
Edit: A poor connection on the neg lug could also produce enuff heat to damage that side...
2M.................I don't recall anyone reporting problems with the Chinese 3 phase rectifiers. I may have missed it. I suggest testing the original stock rectifier on the bench first, then install it on the bike to see how things go.
Leave the headlight off/unplugged, as a test while doing the above, to reduce the load. It can be added later if all goes well.
Leave the headlight off/unplugged, as a test while doing the above, to reduce the load. It can be added later if all goes well.
DanielBlack
XS650 Junkie
That was sort of my thinking, but I'd hate to burn up the good original. I do have another modern, but we think they're suspect. FWIW, the first one to die was a 30A. The second and my spare are 50s. Clearly the two that died were from different batches.
Hi Daniel / All:
I am certainly not an expert at these things but given the number of components that DB has toasted, I think he must have some sort of issue OTHER than the rectifier. hmmmmm.....
Pete
I am certainly not an expert at these things but given the number of components that DB has toasted, I think he must have some sort of issue OTHER than the rectifier. hmmmmm.....
Pete
OK - all you electrical types out there. What else could be causing such sturn und drang for our Daniel? Perhaps a bare wire somewhere in the circuit?
has the regulator been opened, points checked?
Yes shorts, opens, vibration
is the battery tray in it's original mounts? regulator in the stock location not touching undamped items.
Just opened the headlight shell on a new to the shed 81 a grommet was adrift, wire insulation peeled back by sharp shell edges.
Bike "just quit running one night".
Yes shorts, opens, vibration
is the battery tray in it's original mounts? regulator in the stock location not touching undamped items.
Just opened the headlight shell on a new to the shed 81 a grommet was adrift, wire insulation peeled back by sharp shell edges.
Bike "just quit running one night".
DanielBlack
XS650 Junkie
VR291 regulator mounted with the rectifier in the stock rectifier position.
Stock battery box on stock mounts.
I'm going to do a thorough wire check this evening.
Stock battery box on stock mounts.
I'm going to do a thorough wire check this evening.
I've just about run out of ideas to help you, but here is something. The regulator must have a good ground connection on its black wire, in order to control voltage. If it loses the ground, it will default to maximum voltage output from the alternator. Are you sure the black wire coming out of the regulator has a low resistance path back to the battery negative? A resistance check should show a short circuit i.e. 0 ohms.
I would check the ground wire in the harness for the rectifier too. All the ground wires for various things that go into the harness hook together eventually and exit as one black wire up by the coils. It connects (grounds) to one of the coil mounts. As far as I know this is the only ground point for all those ground wires in the harness.
I've encountered a couple messed up rectifiers on these. It usually shows as a melted plug. Sometimes it's mostly the ground wire and sometimes it's burnt right off. This leads me to think a bad ground could be the culprit. Sometimes the damage to the ground wire extents up into the harness as well.
I've encountered a couple messed up rectifiers on these. It usually shows as a melted plug. Sometimes it's mostly the ground wire and sometimes it's burnt right off. This leads me to think a bad ground could be the culprit. Sometimes the damage to the ground wire extents up into the harness as well.
DanielBlack
XS650 Junkie
Checking that ground will be next step. I've removed the stock harness and ran a new custom scheme. The grounds for my rectifier, regulator, and SSR all run on one 16g wire from under the battery box straight to the neg battery lug.
Isn't the battery box rubber mounted?
DanielBlack
XS650 Junkie
Yes, the box is rubber mounted, but the components have their grounds run via wire to the neg battery lug. I have replaced just about all frame grounds with wire run to the neg lug.
TimeMachine
SeventyEighte
Hello DB & , I've been wondering if having an extra ground wire which actually grounds the battery box also is a bad idea ? Thx, -RT
On my combo reg-rectifier unit - in addition to the black ground wire in the units wiring harness, I actually drilled a hole in one of the cooling fins and used a self-tapping screw to secure a ground wire to it and to a big bolt nearby on the frame.
I was told by someone that the harness ground was not sufficient
and that a separate ground from the chassis of the device to the frame of the bike was also needed.
Pete
I was told by someone that the harness ground was not sufficient
and that a separate ground from the chassis of the device to the frame of the bike was also needed.
Pete
*whew*, finally found it, RG.
About halfway in.
http://www.xs650.com/threads/first-fire-up-and-strange-noise-developed.45219/
And here:
http://www.xs650.com/threads/over-charging.45875/
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DanielBlack
XS650 Junkie
Grounding the case of the rectifier and regulator is an interesting thought. I can give it a try.
I will note that I have 0.0ohm continuity on their built-in grounds to the neg battery post.
I will note that I have 0.0ohm continuity on their built-in grounds to the neg battery post.
Hmmmmm...I'm out of my depth on this Daniel. It just seems to me that there must be something else wrong for you to keep blowing these normally robust components.
Pete
Pete
DanielBlack
XS650 Junkie
Well, the Chinese 3ph rectifier might not be so robust.
Alright, plan of action:
Alright, plan of action:
- Check wired component grounds to rectifier and regulator
- Add ground to reg/rect mounting plate
- Bench test new rectifier, replace the burnt one.
- Fire her up, and check voltages and currents at idle. I'm borrowing a Fluke meter from work with a fork ammeter. I'll also keep a regular eye on the rectifier temp across time and voltage. After a while at normal idle, I'll push it to a fast 14.2v idle and see how it goes for a bit. Then add the headlight.
