Don't panic. You'll grow new skin in a couple of days

 

First off..... Me took a shower and went haywire with the lint roller . Wify was like ....If it works who am I to argue..eh!
Man it feels good now.

OK ! At 600 Hrs I went to install the panel and I got more than I ever bargained for, again.

The harness had no Ground wire. I checked and checked but nope..no ground what so ever......that's funny ! How did the engine start at first. ?

The Alternator light does not turn on, checked and guess what. the wire was simply twisted around the lug. That's the best any body can do these days. But alternator is fried...I checked the battery voltage after starting....No increase in but it stays below 24V...when engine is running.

Everything else works like a charm.....I was at it for like 5 Hrs straight.

The Tacho is not there. The previous one is a sender for the Gear oil pressure.

The Alarm works as intended. The Senders and switches works just fine.

Oh yeah ! one more thing..It did not start at first.....the nut on the starting solenoid wire was missing. ...

I wonder if these things are done deliberately...

 

If the Alt lamp is blown then the altenator will not charge. To check, with the engine not running but Ign on, if the lamp doesnt light short L to Gnd & the lamp should light. If it does then the circuit & lamp is Good.

 

A bit on 2 different ways an altenators regulators & how they are conected, externaly or internaly & these Regs are 12V. Inside there is 6 main diodes for the charging circuit. There are 3 smaller diodes, these are Field feed diodes. The Charge lamp feeds a small amount of current to the Reg/Rotor to initialy excite it & the lamp will be on. When the engine is started & the altenator starts charging, the field feed diodes take over suplying the Reg & Rotor. The Voltage is then the same as whats at the Ign switch & the lamp then goes out. The 2 different circuits are just the way the Rotor is wired. The Bosch one one side of the Rotor goes to Gnd. The other one the Rotor is conected to the power side. Hope this is some help on what to look for.

 

I checked like that.
When I touch the L wire to the engine body. Charge lamp lights up.

So?

 

Gues hes gona need a new Reg or Altenator then. Just curious was the Tacho working before? Nice panel now.

 

No tacho what so ever. ..

I am gonna bring the Alternator to repair

 

If your gona play with the alternator, you may want to run a wire from one of the stator windings before a diode to the outside of the altenator. This will give you an AC voltage with varying frequency. Ive done this mod before to run a VDO tacho on a tractor. This just might run the Tacho.

 

U are saying that the current RPM meter might except that AC voltage.

 

I've got a dumb question, since alternators are "usually" overdriven (at a higher than crankshaft speed) how is the alternator used as a tach signal?

 

I've got a dumb question, since alternators are "usually" overdriven (at a higher than crankshaft speed) how is the alternator used as a tach signal?

A simple solution is to acquire a reading from the engine flywheel with a handheld optical tachometer and then adjust the gauge accordingly.
this method is not totally accurate but very close.

 

rough guide to rpm from alternator.there is usually a terminal on the back of the alternator that is a tapping from one of the stator windings. this gives a varing frequency voltage acording to rpm. the rpm guage is then just a frequency counter calibrated to reflect the engine rpm. seen loads where the wrong pully is fitted and the rpm reads way out. this tapping is also used to signal some run relays that the engine is rotating and allow protection systems to work. not all alternators have the external connection though.
on a lot of rpm guages there is a little screw to adjust the rpm reading. you can actually do the maths of the frequency of alternator verses rpm along with pully sizes and just measure the tapping output with a multimeter on frequency then calibrate the rpm guage. on the other hand i use a hand held optical rpm guage triggering it on a fly wheel or front pully lot easier.

 

love the original wiring obviously done by an expert . when we had guys like that in the workshop we had a name for them SACKED.

 

found a simple description of the maths. just work put the drive pully ratios and your there.

 

This altenator has a Star winding & the taping point is the center of the star, where the 3 windings terminate. This should be a good point to put a Tacho feed. The CRO is set at .1v/CM & probe X10. horz .2ms/CM. The engine was around 700RPM.

 

Thanks guys, I'm pretty good with gasoline engines but have never worked on a diesel.

 

if tapped from the star join then the freq is 3 times the rotation speed multiplied by half the number of poles on the field coild (rotating part.) if taped of one phase wire then just the rotation speed multiplied by half the number of poles.
Assuming a standard V belt drive, you can't just measure the outside diameters of the pulleys. What is required is the diameters (or radii) to the neutral axis of the belt, which will presumably be closer to the top than the bottom, especially if it is notched.

 

if it helps this is the wiring diagram for the yanmar 4che3

 

The 4CH E3 is a later model turbo charged. Uses a totaly different Tacho & its sender is a Magnetic sensor that is fitted to the bell housing & counts ring gear teeth.

 

@ REHTNAP.. I had that, it was my guide to figure the harness u know.

Alternator will be here to day. I am not going to get it out...too much work for a big guy u know.