Tacho running backwards??

[leenolan82]

HI Guys.

I have just replaced a faulty rectifier on my J60TLCIH. wiring all same as diagram but my tacho seems to be running backwards. also motor doesnt seem to be charging?? any help would be greatly apprecieated.

cheers guys!!

 

[metriccrescentwrench]

Re: Tacho running backwards??

What do you mean by the tachometer is running backwards?

 

[leenolan82]

Re: Tacho running backwards??

starts at 0 rpm and the needle goes backwards, as in anti clockwise.

 

[metriccrescentwrench]

Re: Tacho running backwards??

Are you sure the engine's not running backwards?

I've got two guesses, bad tach or + and - swapped on it.

OK, maybe a third guess. Are you absolutely positive you hooked up the new rectifier according to the manual? (You are using a factory service manual, right? If not I'd consider investing in one, they're way better than the generic manuals.)

As far as charging, there's not much to the charging system. Basically the stator, flywheel magnets, and rectifier/regulator (and the associated wiring and connectors). Oh, and of course the battery, which needs to be in good condition to take a charge, and the battery cables and connectors.

 

[NetDoc]

Re: Tacho running backwards??

Its time to pull out a DVOM and check polarity. You might be harming some fragile circuits and I'm not talking about the tach!

 

[leenolan82]

Re: Tacho running backwards??

Its time to pull out a DVOM and check polarity. You might be harming some fragile circuits and I'm not talking about the tach!

What polarity checks should I be doing. The service manual I have does not mention anything about checks for this. It basically said that the rectifier needs to be wired as per wiring diagram. Which it is. Now stator and rectifier have been replaced but the batt voltage is still only 12.2v with engine running. And I also have this tachometer issue....

 

[NetDoc]

Re: Tacho running backwards??

What polarity checks should I be doing.

Make sure that the alternator is producing a POSITIVE current. Put in a diode pack backwards and it will effectively change how it "charges" your system.

Here is an alternating current sine wave:

Wired correctly and a diode pack will cut of the bottom portion, leaving something akin to only bumps. Wired backwards and you'll cut off the tops, leaving only the valleys. Put a capacitor and you'll level the peaks or valleys and remove that annoying whine in your radio! A good alternator always produces more voltage than a battery, so you're actually discharging it. Can diode packs be mislabled? You betcha. Here is a basic way to test a diode: http://www.elexp.com/t_test.htm Easy as pie.