2011 Transit connect not charging after jump start

[dieseldane]

Thought I would run this by the (sometimes ) knowledgeable folks here at TRS. Last weekend I left the power inverter on in my service van. Jump started it Tuesday morning, and afterwards, the charging system was not functioning. Could start the van, and put a meter on the battery and only getting 12.0 volts while running. We swapped out the alternator, and still getting same voltage. I have read that the voltage regulator is built into the pcm on these. Is that the next step, or are there some fusible links or diodes within the wiring harness that can be checked first?

 

[adsm08]

Regulator is on the alternator. The PCM does tell it how much voltage it wants though.

The test says to make sure the battery is at 12.2 or better before testing the system, then you just check voltage drops.

Put meter positive on alternator housing, meter negative on battery negative. Any reading higher than .25V shows a ground problem.

If ok put meter positive on B+ terminal on alternator, meter negative on battery positive. Any reading above .5V indicates a poor connection between the alternator and the battery.


Those test are done engine running at idle, headlights on and blower on high.


12.0 sounds like charging but something is drawing the system down or it's just charging weakly. Running on the battery rarely gives you more than 11.5.

If you want to do a quick test of the alternator itself unplug the little plug for the regulator, start the engine, and rev it up past 2000 RPM for 5 to 10 seconds, then return to idle. You should have 13.5 at the battery.

 

[dieseldane]

Thank you sir, I will go and check that out to make sure everything is working like it should. Boss was looking at it again last night ad found that the 200 amp fuse in line with the battery + to the alternator was popped. Not sure how that happened... Thanks for the info adsm08!

 

[enjr44]

Not saying you did; but, if someone hooks up the jumper cables backward you can blow that fuse.