88 SPL Charing Issue?

[trenth]

I have a 1995 88 SPL. Normally my volt gauge will read anywhere from 13-16 volts with the engine running. Today I noticed the guage read 12 with the engine running up to 5000 RPM and also read 12 with the engine off. It's acting exactly like it did a couple of months ago when my rectifier went out (I replaced it and it worked fine). The tach is also working fine right not. The current rectifier checks out OK per the OEM manual test. I also tested the stator resistance and got 2.5.

A multimeter straight to the battery reads 12.6 volts. With the engine running on muffs at 1000 RPM the same test reads 12.8 volts. So it's charging a little bit but not like I'm used to. Any idea of what to check next?

Thanks

 

[wilde1j]

Re: 88 SPL Charing Issue?

It's not charging. Start by checking the AC input to the rectifier from the stator ... you should get > 30VAC (typically measured across two yellows). If you don't get a decent AC voltage there, the stator is fried. You need to also check that all wiring is intact and terminations are tight and clean. Never run the motor and disconnect any battery leads ... it will fry a rectifier in a heartbeat. Battery voltage (motor running at a moderate idle) should be => 13.5 VDC (12.8 doesn't count ... a fully charged battery will be at or near 12.68 VDC static voltage).

 

[trenth]

Re: 88 SPL Charing Issue?

I just tested VAC but not sure if I did it correctly...? With the engine running I hooked a multimeter lead to each yellow terminal on the terminal block. I got 15.5 VAC. I then put the black multimeter lead on the rectifier mount bolt (ground) and red to the red wire on the terminal block. I got 28 VAC on that test. Are either of these tests correct?

 

[wilde1j]

Re: 88 SPL Charing Issue?

!5.5 vac is not good. Stator is likely cooked.

 

[trenth]

Re: 88 SPL Charing Issue?

So I did perform this test correctly? I simply touched the multimeter leads to the two yellow stator wire terminals on the terminal block. I did not disconnect the stator wires.

I just want to be extra certain before I drop $200+ on a new stator.

Thanks

 

[trenth]

Re: 88 SPL Charing Issue?

Should the yellow stator leads be disconnected from the terminal block for the VAC test? They were connected for my test that yielded 15.5 VAC.

Thanks

 

[wilde1j]

Re: 88 SPL Charing Issue?

That's correct ... never disconnect any wires from a running motor! There are also resistance checks for the stator ... check the shop manual.