Regu/Rectifi, Multimeter, CO Detector, Fire Truck

[BPC23 18]

Believe it or not, there is a serious question at the end of this story, but I felt it necessary to tell the whole sad, but true, tale. If you want to skip the drama, scroll down until you see QUESTION.

I became a Mechanical Engineer because I don

[Save Old Iron 1,563]

voltage measures 13.75V with the ignition off. The voltage across the battery terminals measures 14.25V at idle and 18V at high speed. The amperage across the main fuse (no accessories on) is 1.5A at idle and 8+A at high speed. Do these values at these speeds sound right?

Brian,

thanks for the kind words about my posts and a very interesting story from the home-front.

The 18 volts at full throttle is not correct - the voltage regulator, should do just that - regulate the voltage to the battery REGARDLESS of engine speed.

I'm thinking you have a poor ground to the voltage regulator heat sink (aluminum fins).

To confirm this theory, run a ground wire directly from the bolt head holding the regulator to the chassis directly to the battery negative terminal. This single wire will bypass all the rusty connections thru speed clips, rusty panels and rusty screws and bolts.

If the voltage to the battery drops to the 14. something range at full throttle - problem solved. If not, you MAY have a bad regulator.

AS far as the LED's dimming at times, that is most likely the LED's going into a self protection mode when your feeding them 50% more voltage than they where designed to handle (18 volts vs 12 volts). The extra voltage has to be dissipated as heat and the LED's are going to dim to save themselves from destruction. The technical term is thermal foldback.

Getting the full throttle voltage down to 14.something will solve both issues.

[Save Old Iron 1,563]

Trying to emulate SOI = massive FAIL

[WheelHorse_of_course 99]

Brian,

thanks for the kind words about my posts and a very interesting story from the home-front.

The 18 volts at full throttle is not correct -

I'm thinking you have a poor ground to the voltage regulator heat sink (aluminum fins).

To confirm this theory, run a ground wire directly from the bolt head holding the regulator to the chassis directly to the battery negative terminal.

Brian,

Actually you may want to jumper BOTH bolts to a good ground as as some fuzzy nut-head determined there is no PC board trace between the two grounding points on the sacrifical regulator that was vivi-sected.

Best of luck!

:banghead:

[BPC23 18]

Thanks for the tips guys. I've got a malfunctioning regulator/rectifier.

I attached my ground wire from a cooling fin of my unpainted reg/rec housing directly to the negative terminal of the battery and I still have 18V at high speed. After removing the jumper, I double checked continuity from the battery negative terminal to the reg/rec housing and mounting bolts, chassis ground, accessory grounds, etc. and everything is connected.

I took the reg/rec off the chassis and verified that the two circuit board mounting screws were tight and had continuity with the housing, which they did.

I hesitate to keep running the tractor for fear of damaging any of the other components of the electrical system. I'm probably in hot water if I fry my electric PTO, because it doesn't look like these things are commonly available.

Brian

[Kelly 1,028]

if you need to use the tractor before you get it fixed, you could leave the plug off the reg, that way you will be just running off the batt. I don't believe it will hurt anything, I'm sure someone will corect me if wrong.

[Save Old Iron 1,563]

What Kelly says is a good alternative.

It is only when you run the tractor without a battery attached that you can start to feed voltage spikes into your electrical system from the action of the regulator.

I believe several tractors have warning labels advising against running without a battery attached into the electrical system.

[BPC23 18]

I purchased and installed a new Kohler 25-403-22 regulator. Now my voltage is holding steady around 13.5 - 14 volts, regardless of any accessories being on or off. However, my amperage is acting a bit funny,,, maybe. Looking at the ammeter when accessories are on shows positive (+) amperage at idle , and negative amperage (-) at high speed. This is reverse of what you would normally expect, which therefore makes me think I have my ammeter connections backward. I guess diagnosing that will be my task for this weekend.

[Save Old Iron 1,563]

Brian,

you nailed that problem too.

Wires are reverse on the ammeter. :banghead:

[BPC23 18]

Chuck, of course I nailed it! I studied your course on ammeters!