One Click and then all power dead - battery seems fine, Starter Contacts?
 

From the searches I've done, it sounds like this might be a case of starter contacts but I didn't find my exact use case so wanted to get some input/thoughts before I headed down the wrong path.

This is my daughters 4runner - last week she wasn't able to lock with the key fob going into a meeting and she didn't think much about it. After she came out about an hour later everything was dead - no power to anything, no clicking, nothing. A friend gave her a jump and everything seemed fine. I thought she must have left something on by not locking with the fob. She drove it several days with no issue.

Yesterday, similar thing - she drove in the morning and everything normal, was able to lock, etc. Then when she went to drive in the evening, everything was dead again.

I went over to give her a jump and troubleshoot. No power anywhere, lights were in off position, same with dome light so didn't appear to be a drain issue, It presented as if battery was fully dead or not connected. I jumped it and it started right up which seemed odd, if it was completely dead, it should have taken some time to charge.

Battery is only one year old. Tested voltage in off position, tested good at 12.93v - no visible drain. Tested with car running at 14.3v, so alternator is charging. I swapped her cars and took it home to troubleshoot further.

I tried several ways of unlocking and starting and nothing seemed to be an issue. I checked battery again this morning and the drain overnight was minimal - 12.93v down to 12.8v so not an apparent drain issue.

I was going to take it to AutoZone to do a battery test. It had power to lights, clock, chime, etc. Turned key to start and one "click" (couldn't tell where from) and everything went dead - the starter never turned over, and now there is no power to anything. Battery is still at 12.8v. Can't use power locks, dome lights, no light on the ignition ring, etc. It's as if the battery is disconnected.

I could possibly try to jump it again to take it to AutoZone to test but since I am in this state, figured it would be good to test what I could to validate before resetting whatever might be causing the issue. If the starter contacts are bad, would that cut power to the whole car? Is there a relay I should test? My next research will be to locate the wiring diagram to determine where the first break in circuit from the battery could possibly happen.

Thanks in advance for the help!
Jeff

When it seems like a dead battery where are you testing the battery voltage at?

When it happens next time read from the frame to the two big wires in the underhood junction box.

If you read zero volts check negative terminal on battery to the same two wires.

If still zero volts then read the negative terminal to the positive terminal.

If you’re reading 12.8v and it seems like a totally dead battery it’s a connection on one of the battery posts.

Do you own a battery terminal and post cleaner?


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I've been testing at the battery posts/terminals + to -

I only see one large wire in the fuse junction box (positive feed). Voltage from that wire to frame is 12.8v and from negative terminal/post to large wire is also 12.8v. Would that lead you to believe this is a starter relay issue (the large relay in corner of fuse box)? If so, I could remove and test but not sure how to test (what normal and functioning would be). There is a diagram on the top, but not sure what state is expected and triggered and how to trigger.


Yes, the connections look good and no corrosion. I was going to disconnect and clean but was thinking that might reset the issue and stop my troubleshooting so waiting to do that since it had been fine for a while so bad connection doesn't seem to be an issue.

Interesting behavior, testing the voltage in that manner to the fuse box appears to reset something because power is back but then I try to start again and it goes back to disconnect state with the one click. Now trying again, it isn't resetting and the testing polarity is switched - the large wire in fuse box is only reading voltage to + terminal and not to the frame.

When it’s dead you have no headlights?

A high resistance connection will show full voltage with no load.

If my above statement is true then do the test again with the lights turned on and not working. If your battery truly is good you should find a bad connection somewhere. Your lights do not go through the ignition switch.


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The headlights were not working as well - nothing of any power would work which seemed odd.

Lesson learned (relearned), I went down a troubleshooting path and didn't start with the easiest and cheapest option first. :doh: I should have known because I had a similar issue with my son's 3rd gen as well with bad connection at battery terminal a couple years ago.

I cleaned up the posts and terminals and now it starts no problem. While there was no corrosion, they weren't shiny and super clean. It seems that the 3rd gen 4runner is extra sensitive to lack of a quality connection (maybe because the positive terminal is two thin bands that wrap around the post rather than a solid one like the negative).

I'm thinking once the battery dropped below a certain point of charge, it wasn't enough to overcome the bad connection. Not knowing how the ignition and starter system functions, still a little baffled by what I was seeing with full power cut out and reversed polarity. :shrug:

We'll see how it goes and if that solved the problem.

Thanks for suggesting to start at the beginning :) and for your help thinking through the troubleshooting!

I coat my terminals with a conductive grease to help.


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I just use petroleum jelly.

I really think you need to pull those terminals, clean, inspect and reattach making sure they are tight. . It's easy for a terminal connection to look good but still be bad. A stripped nut is invisible but will leave the connection iffy. BTDT.

I also use petroleum jelly on battery terminals.

So I had to add my nickel in here. The terminals(actually cable ends) are often deceiving, as others have pointed out, in that the cable itself gets heavily corroded and doesn't make good contact with the cable end. You can't only focus on where the lead post contacts, but further up or down stream as well. And for the record, out here in good Ol' Cali 4 Ny A, we don't need no stinking vaseline! Haha. I actually just run water over the terminals every other time I wash the truck, or thereabouts. Water is a great neutralizer of the sulfuric acid instigated corrosion. Also, we don't have to deal with the snow and salt and all that other misery.

Ok as you were...

https://uploads.tapatalk-cdn.com/202...84156be024.jpg
This is what I use. Used it in manhole ground connections and preformed flawlessly in keeping corrosion at bay for the corona drains etc.

The crimps could have corrosion in them also. I recently bought new positive terminals from Toyota the design is much better than the old ones.


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I agree with all you said. I also always check the insulation for any bubbling or discoloration which is an indication of invisible corrosion within.

I stressed the terminal because he is totally dead but can jump and he had not yet even removed the terminal or tested the tightness. As you well know, "it looked good" are some of the least reassuring words in auto-electrics.

If that's not it, cables and the other end of the negative are the next places to go. I'm pretty sure it's a main battery connection problem rather than anything else, although I would not touch the car myself until I slapped my load tester on that battery. Just one of my rules. Check the dang battery first. Then remove and clean the terminals and the ground connection. Needs done anyway.

By the way, bolt-on repair terminals are instruments of Beelzebub. If you have one of those, get a pro to do the terminal or get a new cable (preferred at the age of our trucks)..