Tmax xp500 charging fault

[Taipan]

The Tmax isn't charging. They are not exactly unknown for burning out reg/rectifiers. I got a supposedly good s/hand reg and chucked it on today but it hasn't cured it. So i decided to start taking some readings on both regulators off the bike and it looks like s/hand one is faulty but the one that is on there is within spec? Can anyone check my work and confirm this?

OEM Reg. Using a DMM.

Positive probe to regulator negative connector and the reading from each of the 3 phase connectors.

con1 511 - con2 500 - con3 520

Negative probe to regulator positive connector

con1 521 - con2 520 - con3 525

S/hand Reg. Using a DMM.

Positive probe to regulator negative connector and the reading from each of the 3 phase connectors.

con1 519 - con2 1 - con3 522

Negative probe to regulator positive connector

con1 532 - con2 533 - con3 520


I'm thinking second hand one has faulty diode and no good, but the OEM one is within spec, or are those figures too far apart?

Moving on to checking the stator, iirc, any continuity between any of the 3 phase wires and earth means it's had it?

[DefTrap]

That electrex fault finding guide - always a winner https://www.electrosport.com/pages/technical-resources

"When you find that there is a problem, keep in mind that the number 1 problem with any charging system are bad connections."
And battery, obvs.

I only mention it because of the numerous crappy bikes with crappy electrics I've had over the decades, it's ALWAYS been one of those two.

[wull]

Check output from the alternator.

Best way to test it is the actual voltage output which is AC with the meter range set to at least 500

All you have to do is test each wire, so one probe on one pin and the other probe on the other pin until you have taken the 3 readings, all 3 should be within spec so check the manual, usually done with the bike revving @ 4K but can vary.

[Mr. Dazzle]

BTW....I've been caught out before by a digital multi meter with a dying battery. They generate pseudo random readings, so if you're scratching your head at the weird numbers you're getting try changing the battery in the meter

[Taipan]

Got an interesting reply from a knowledgeable chap. Seems it may be my regulator after all? One is winging its way to me as we speak and I'll do that 10-minute job as part of the elimination process. I also have a stator winging its way to me in case it isn't the reg. That is obviously a much more involved job though, so fingers crossed on the reg being at fault!

"The GAP of testing between NEG and POS should not have that much GAP. and it should be Very CLOSE to each other. Is your bike a yamaha TMAX 500? reading is quite high as per my example...

Here's your gap 511/521 - 500/520 - 520/525

as you can see the new rectifier gap is 464/463 - 463/464 - 471/471

Damage rectifier - 469/466 - 466/469 - 470/475"

[Scootabout]

I know nothing about any of that, but I do remember my TMax 500 ate batteries at a pretty alarming rate - about one every two years. Whether that's connected to the issues you are talking about I don't know?

[Taipan]

There are no charging volts going in. I think it's the stator and I have a new one but was waiting on Hermes to deliver the new regulator on Thursday or Friday last week. It turned up at 18:15 last night! The regulator is a 10-minute job to change but the stator is a lot more involved, hence why I wanted to check the new reg first.

[iansoady]

Probably unlikely but if you have an issue with the stator it could kill the reg/rec........

[wull]

Test the stator, it’s piss easy to do.

[Taipan]

Test the stator, it’s piss easy to do.

Yes i will do. DMM needed a battery and then I buried the bike under a cover and had some old cupboards I was cutting up in front of it. I'm pretty sure the stator has gone as before my meter battery croaked, I'm sure I got continuity to earth (I think) on one of the circuits? Anyway, the bike does run so I can test static and dynamic as well.

[wull]

Yeah test the voltage output of the stator windings as well, I always find this will give you better results.

[Taipan]

Yeah test the voltage output of the stator windings as well, I always find this will give you better results.

Meter on AC volts with the bike running and probes across each of the three wires, 2 at a time right?

[v8-powered]

Yeah test the voltage output of the stator windings as well, I always find this will give you better results.

Meter on AC volts with the bike running and probes across each of the three wires, 2 at a time right?

Yep - 1 to 2, 2 to 3, 3 to 1. Should all be same voltage.

[wull]

As above, try and find out what the manual says with regards to the output, it’ll probably be something like 40-50v @4k so make sure the meter is set to a minimum range of 50v AC.

[Taipan]

Manual says,



AC volts readings

1&2 idle 25 5k 74
1&3 idle 20 5k 74
3&2 idle 21 5k 73

OHMs

1&2 0.5
1&3 0.5
3&2 0.5

Resistance across the probes 0.3 So I'm about in spec, right? But all the wires sound the continuity bleeper when connecting any of the 3 wires to earth. So the stator is shot? Thoughts?

TIA

[v8-powered]

If you have continuity to earth then its fit for the bin, what is the actual resistance between phases and to earth?

[Taipan]

If you have continuity to earth then its fit for the bin, what is the actual resistance between phases and to earth?

2.4 on all 3 phases.

[v8-powered]

If you have continuity to earth then its fit for the bin, what is the actual resistance between phases and to earth?

2.4 on all 3 phases.

2.4 Ohms to earth? That sounds like it's farked then.....

[Taipan]

If you have continuity to earth then its fit for the bin, what is the actual resistance between phases and to earth?

2.4 on all 3 phases.

2.4 Ohms to earth? That sounds like it's farked then.....

Thanks. On it, like a car bonnet!

[weeksy]

Oh you can get a high resolution pic.

I really wish that wasn't possible