Electrical Gremlins Reverse Polarity - 5 Hours into Fix - Struggling with Next Steps

[Sir.T.Grant]

Good Morning,

Situation: While I was out of the country, an unnamed Family member attempted to use my 4Runner and attempted to "jump start" it using jumper cables. Unfortunately she managed to reverse the polarity (switching pos/neg) and kept the cables connected for over 5 mins.

Corrective Action Taken to-date:
1) Replaced Battery
2) Replaced Alternator (that was fun...)
3) Replaced all the blown fuses in the engine compartment fuse block including the 60 AMP alternator fuse.

Current situation: 4Runner starts when battery is fully charged. and it seems to maintain a charge for 5-10 mins. Then the battery quickly (within 4 mins) drops from 12.2volts to <10volts and the car fails and needs to be (correctly) jump started. The 4Runner illuminated dash lights for Traction Control - ABS - Battery Icon - and BRAKE. The only other observable issue is the A/C does not work but the FAN does...

Does anyone have a suggestion for a next course of action? What to check to possibly replaced?

 

[fkheath]

Good Morning,

Situation: While I was out of the country, an unnamed Family member attempted to use my 4Runner and attempted to "jump start" it using jumper cables. Unfortunately she managed to reverse the polarity (switching pos/neg) and kept the cables connected for over 5 mins.

Corrective Action Taken to-date:
1) Replaced Battery
2) Replaced Alternator (that was fun...)
3) Replaced all the blown fuses in the engine compartment fuse block including the 60 AMP alternator fuse.

Current situation: 4Runner starts when battery is fully charged. and it seems to maintain a charge for 5-10 mins. Then the battery quickly (within 4 mins) drops from 12.2volts to <10volts and the car fails and needs to be (correctly) jump started. The 4Runner illuminated dash lights for Traction Control - ABS - Battery Icon - and BRAKE. The only other observable issue is the A/C does not work but the FAN does...

Does anyone have a suggestion for a next course of action? What to check to possibly replaced?

First thing to do is check the battery voltage while the engine is running. If the voltage is 14.1 volts or a bit higher, that shows the alternator and charging circuits are working. If all you are getting is 12.2 volts with the engine running, the battery is not being charged.

A sudden drop of the battery from 12.2 to 10 volts indicates a bad cell in the battery (each cell is 2 volts since there are six cells in a 12 volt battery).

 

[Sir.T.Grant]

Instant Check.

Thank you for the quick response. I tested the battery prior to starting and it read 12.9volts. Ran it for six minutes and it held in the high 12s for 5 mins then feel off precipitously and dropped to 11.0/10.9 before I turned off the rig.

 

[2021nightshade4x4]

Thank you for the quick response. I tested the battery prior to starting and it read 12.9volts. Ran it for six minutes and it held in the high 12s for 5 mins then feel off precipitously and dropped to 11.0/10.9 before I turned off the rig.

Alternator not providing correct charging voltage


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[rigtec]

Good Morning,

Situation: While I was out of the country, an unnamed Family member attempted to use my 4Runner and attempted to "jump start" it using jumper cables. Unfortunately she managed to reverse the polarity (switching pos/neg) and kept the cables connected for over 5 mins.

Corrective Action Taken to-date:
1) Replaced Battery
2) Replaced Alternator (that was fun...)
3) Replaced all the blown fuses in the engine compartment fuse block including the 60 AMP alternator fuse.

Current situation: 4Runner starts when battery is fully charged. and it seems to maintain a charge for 5-10 mins. Then the battery quickly (within 4 mins) drops from 12.2volts to <10volts and the car fails and needs to be (correctly) jump started. The 4Runner illuminated dash lights for Traction Control - ABS - Battery Icon - and BRAKE. The only other observable issue is the A/C does not work but the FAN does...

Does anyone have a suggestion for a next course of action? What to check to possibly replaced?

Hi Sir.T.Grant,

There are a couple of things I would be testing for in that situation:

(1) The 140A Alternator Main fuse, and pull/check ALL fuses in D/S & Engine RM boxes, (...I'll post a electrical diagram below for Main ALT fuse)! And check... (2) Center Point Steering Calibration & Yaw Rate Acceleration Calibration!

If those two calibrations are "NOT" Set properly, you'll get EXACTLY as you've described on the instrument cluster, e.g. ABS, SKID, BRAKE! ...see diagram 140A fuse highlighted in Blue to determine if it's Blown; [NOT(conveniently) Replaceable]:

~rig~ Best to you!

 

[Too Stroked]

What brand of alternator did you put in? The reason I ask is that I've seen way too many parts store (particularly O'Reilly's) alternators arrive DOA.

 

[Sir.T.Grant]

Updates.

1) Replacement Alternator was a brand new (not remanufactured) WAI Global.

2) On the recommendation of some team members, I have verified the 140A that was replaced is still in tact. Further. I checked every single fuse both in the engine compartment and driver's footwell. I am still not having any issue.

At this point I am at a loss for what to check next? Any suggestions/hopes/prayers?

 

[rigtec]

1) Replacement Alternator was a brand new (not remanufactured) WAI Global.

2) On the recommendation of some team members, I have verified the 140A that was replaced is still in tact. Further. I checked every single fuse both in the engine compartment and driver's footwell. I am still not having any issue.

At this point I am at a loss for what to check next? Any suggestions/hopes/prayers?

Hi Tyler,

In the above post, you said: "I am still not having any issue.

At this point I am at a loss for what to check next? Any suggestions/hopes/prayers? "

Is that what you meant to say or, "I am STILL having an issue...(?)!" Just checking to make sure I'm understanding correctly here! If you ARE still having this issue... check a few of these Commonly overlooked test points: At the alternator's pins, S (Vio), B (WH), IG (Gry), and L (Pink): M (Blu)= Monitor/CAN-bus; I'm not sure what that value should be!) With the Alternator's plug disconnected and power "ON", test for 12V in the plug cavity!

If you have 12V at S, IG, and L..., Time to do a ECU Master RESET to make sure that the CAN-bus system isn't preventing the alternator from charging; I've had that happen to me while driving..., "Yaw Rate and Center Point Steering Cali needed at the time!!"

Disconnect the battery! Using a small jumper, jump the POS and NEG cables together for 10 minutes; it shouldn't take that long, but we wanna do this only ONE TIME! Reconnect the battery cables to the battery and start the truck. It'll start, run for 2 seconds and SHUT-OFF; this is "NORMAL!" That just verifies that the ECU's have been RESET! If it's charging, we're GOOD! If not...,

There's one more thing that I would do to check that the alternator has what it needs to produce a charge. Get a 4ga x 19" battery cable, and run it from the B terminal on the alternator to the POS terminal on the battery (Back-feeds the ENG-RM fuse-box), and test the output; should be +/- 13.5-14.0 if it's working! I know it a pita, but we don't wanna miss any steps in the analysis process!

~rig~ "Please let us know... or questions!"