Starter or Alternator

I totally agree here. I would not recommend this on these modern vehicles. Back in the day for the older vehicles you could get away with that but nowadays DON'T DO IT.

 

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With the battery disconnected, the electricity produced by the alternator is a polyphased AC sine wave. It can have peaks that will exceed the maximum voltage that the vehicle's electronics was designed for. A connected battery acts like a large electrolytic capacitor and filters the sine wave to convert it from AC to DC.

If you need to test an alternator on the vehicle, use a DC voltmeter to test the output voltage (for regulation), an AC voltmeter to test the AC ripple (for open diodes), or a clamp-on DC Ammeter (for load). Depending on the ambient temperature, RPM and battery's State-of-Charge, a healthy OEM alternator will produce between 13.6 and 14.4 VDC and vary as the load and RPM change. The AC ripple (measured at the alternator's output terminal), should be less than 0.5 (500 millivolts) VDC.

For more information on batteries and vehicle charging systems, please see the Car and Deep Cycle Battery FAQ on www.batteryfaq.org.

 

Didn't see this till I was already going down this road. I picked up a plunger and new solenoid contacts from a local alternator/motor repair shop for $18 (you can probably get them cheaper online but it was Friday and I wanted to get this done over the weekend). The start removal was pretty straight forward. The top motor mount bolt is a pain to get at as it is a really tight fit but it can be down. Did not remove anything other than the starter and I was able to pull it our from the left side of the top of the engine compartment (just had to move a few vac hoses etc.) Popped off the cap on the solenoid and it was obvious this was the problem. I have attached pictures of the contacts in the starter as well as some of the old vs new and the old plunger. The copper was corroded and pitted badly. Replaced and it fired up like a champ and no problems since. I would recommend this. $18 is much better than $100 + for a reman. or ~$300 from a dealer and once the starter is off the truck it took about 20 mins to tear down clean and put back together.

 

Awesome, glad you got it sorted out. Thanks for revisiting with the pics also. You'll probably end up helping more people than you know.

 

Many thanks for recommending to replace the plunger and the photos. I did not realize that they were so inexpensive and good preventive maintenance given that the starters are becoming more difficult to remove.