Alternator or Battery Problem?

It’s only about $177cdn for a new unit locally, is there another way I can test the alternator?

 

Black lead in the middle. Red on the right. For everything other than 10 amps.

As I understand it, please, someone correct me if I'm wrong. That Ford diode replaced a shorting pin that I believe was actually a dead short. The shorting pin is in a feedback loop to regulate the voltage there at the main fuse box rather than directly at the output of the alternator.

Replacing that shorting pin with the Ford diode created a voltage drop with it's for lack of a better description it's turn on voltage. Now, the feedback loop is seeing a lower voltage and increases output accordingly.

Your meter will tell you the voltage drop of the Ford diode:

Set the meter to bottom left of center, 2k with the diode symbol underneath. Now, instead of the Omega symbol, we need to see the diode. Press the mode button and I bet the diode symbol will appear and the Omega symbol go away. These readings are now in volts. The reading represents the voltage needed to turn on the diode. Test the diode, swap the leads and test again. One way should be an open circuit. The other, the voltage needed to bias the diode on, thus the voltage drop.

I hope that makes sense...

 

Will try it tomorrow, thanks again!

 

This may help or you can call them they are very helpful.

https://www.crutchfield.com/S-dxCb55BO2Yp/learn/car-what-is-a-capacitor-faq.html

 

Is this what you mean by short pin?



And yes it is to disconnect the constant loads during shipping to prevent dead batteries. Short pin is installed after the delivery to the dealer.

 

Thanks @Jimmyh for that. TIL some more...

Found this thread, that I thought I had read and comprehended previously. Apparently not...

https://www.tacomaworld.com/threads/agm-battery-charging-alternator-voltage-booster.611314/

Shorting pin, alt S fuse... Same thing right?

I'm wondering if the Ford diode is bad. Especially curious as to the bias on voltage if the diode is good.

 

The bias voltage is ~0.7v.

 

@jowybyo thanks.