Reg/rec Replacement

Gizza clue , which sprint ?

 

If I had to guess it would be this one, but I could be wrong

https://www.triumphparts.gbr.cc/product.php/5734999/

 

Good lord - I thought I had gone through a timewarp there and I was back on the Suzuki forums I used to hang out on. My 1983 GSX250EZ used to get through a reg/rec every 12 months or so in the early 90's and I was lucky that my 2000 SV650 got away without the need for it as I was relentless in cleaning all the connector blocks every six months.

 

I would go back and do the basic checks with a multimeter before jumping in for a new reg / rec, altenator output at the 3 wires into the reg / rec and then check the output from the reg / rec and check the earth connections for a bad / loose connection also the battery terminals.

Quite often reg / rec problems are the result of other issues eg shorts where the insulation has worn through, or the reg / rec not fastened solid to the backplate.

 

They are much of a muchness and all do the same and can be used on lots of different bikes just make sure you get one for the correct alternator but most modern bike use three phase alternators anyway.

 

How do you know that the reg on the Sprint is knackered? have you tested the output? to do this you need a multimeter and with the engine running touch the battery + and - you should be seeing between depending on battery state of charge (check battery voltage first with engine off) 12.6 and 14.2v and report back and we can tell you where and how to check next.

 

As @Dozers Dad has said replace the battery, sounds like its on its last legs from those readings unless theres a load on it with everything off pulling the voltage down.

 

The cessation of the symptoms that made you suspect that there was a regulator/rectifier problem.

 

And less chance of it eating the starter clutch !

 

Check the voltage...you will soon see if its now got a decent charge or not, but putting it on charge for a while will do it no harm providing the charge rate is correct.

 

When my first R/R died in my 250 I assumed it was the battery. Put a new one in and happily rode to work for the next three days until it was too weak to start it a fourth time. You may get a couple of days use if it's not being charged but go through the diagnostics to be sure.

Some friends on another forum recommend these two links: fault finding guide and a guide to reg/rec testing. Along with the advice above you will hopefully be able to methodically go through your bike and determine what's best to do in what order.

 

From your earlier comment it may not be the reg/rec it could be one phase of the alternator gone down or even weak rotor magnetism reducing charge rate, in any case you need to go back and do some more testing as per Sir Trevs guide links.