Battery & Alternator? Troubleshooting

[paolotvl]

Three weeks ago I installed a set of Hella driving lights. I connected them so, if their switch is on, they turn on when I switch on the main lights. Everything works as it shoul and they are connected directly to the battery and activated by a dedicated relay. Last week I used the truck and it died on me. The battery was low and it was not cranking. I charged the battery and checked the alternator. With the extra lights on and the engine idling I get a steady 14.22 volts. I just did a load test to the battery and it seems to be working fine. What would you check next? I have no idea other than the main positive down at the starter. About three months ago I patched it with a bigger wire. But it should not cause this, right? It would not drain the battery... Any idea? Thank you.

PS: If it is the battery, I am going to replace it and install an extra one. Should I also replace the alternator or the stock one will be enough to charge both? Any reason to upgrade that too?

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[350runner]

start with replacing the battery to starter cable. then run the charge wire from the output post on the alternator straight to the positive post on the battery. Use no less then 4 gauge wire. last if your alternator has an open bolt hole in the back run at least a 4 gauge wire from it to the negative post on the battery. this will keep the alternator cool and battery charged fully no matter what.

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[paolotvl]

Thanks.


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[paolotvl]

I checked that and the only difference from what you describe is that the wire from the alternator to the battery positive is not very big (two 12 gage twisted together). I just got stuck in the middle of the road again.... The alternator was giving me 13.2 volts when I checked it last week. So I called my wife and she bought an optima battery at autozone. The truck started right away. Now I wonder if it is possible that the alternator is somehow stopping working once in a while. Is it possible? I don't know what else to do....


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[paolotvl]

I will test the old battery tonight, but I really feel that the alternator has issues...


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[paolotvl]

I just tested the alternator again and it gives me 14.2 volts with no loads and 13.4 volts with everything on (including a pair of hella driving lights). This is attaching the voltmeter on the battery terminals. I just can't understand why the battery gets that low. I just replaced it with an Optima (the only one they had in stock when my wife went there on her way to rescue me, $270!!!) so I will see if this battery gets low as well.


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[firebane]

I just tested the alternator again and it gives me 14.2 volts with no loads and 13.4 volts with everything on (including a pair of hella driving lights). This is attaching the voltmeter on the battery terminals. I just can't understand why the battery gets that low. I just replaced it with an Optima (the only one they had in stock when my wife went there on her way to rescue me, $270!!!) so I will see if this battery gets low as well.


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I would start looking at grounds for everything in the truck making sure they are spotless and they are good.

Have you had the alternator tested? Just because its new doesn't mean its good.

 

[MadOgre]

Clean the junction on the firewall

 

[paolotvl]

Ok, the truck has been sitting I. The driveway the whole week with the new battery in. Yesterday my wife tried to move it and the battery was dead. I left it on the charger at 11 ampere for 2 hours and it still doesn't crank if you try to start it. I tried with the booster at 200 A and the truck started up right away. At the same time I disconnected the negative terminal of the battery and put a multitester connected in series between the battery negative and the ground wire. I am getting 12 milliamperes. I disconnected the fuse of the courtesy light circuit and the reading goes from 12 mA down to 3 mA. So, there is a battery drain in that circuit. But I don't think that is the only issue... I am going to buy a negative terminal/cable and replace the existing one. This is mind bugling


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[paolotvl]

The junction at the firewall is really I'm bad shape. I'd rather not touch it unless I'm 1000% sure it is the problem.


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[paolotvl]

Also, thank you all for your help. I don't get notifications when somebody responds to my post so my apologies for not thanking you right away...


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[paolotvl]

Ok, charged both batteries, now the engine doesn't crank. Tried to jump start it with another truck, it is not cranking. You here the click of the solenoid but it doesn't crank....


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[chengny]

I am going to buy a negative terminal/cable and replace the existing one.

Did that ever get done? The negative cable is just as important as the cable for the positive supply - that the starter has a good path back to the battery negative post.

There is no protection (i.e. fuses or links) or components in the starter motor circuit. The whole circuit is basically just the starter/solenoid, the battery and the two main cables.

If you have those things and they are known to to be good, the starter should crank. The sound of the solenoid pulling in indicates that control power is being supplied from the ignition switch.

Where is the engine end of the negative cable bolted to? Make sure that both ends are clean and tight and there is a good connection to the engine block. If it's bolted to the alternator bracket for example, make sure that the bracket mounts are clean and tight as well. Try clamping the negative jumper cable to the engine block and see if you get any better results when you are trying to jump start it.

 

[paolotvl]

Battery & Alternator? Troubleshooting

A few weeks ago I did add an extra ground wire to the negative terminal connector at the battery. Yesterday I bought a brand new negative terminal/ connector/wire. Just to make sure I kill any doubt.


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[paolotvl]

Checked ground again, it is good, the main ground from the battery terminal goes to the engine bracket. I'm uploading a video to show how it doesn't crank. I'm starting to think this might not be an electrical problem but rather the engine stuck, somehow. This is a very rough truck that I got as a trade for a motorcycle.... So I don't know it very well and it might have a gazillion issues I'm still not aware of


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