Strange electrical problem

[Mike6158]

I changed the engine oil and installed a 2m/70cm antenna today. I drove it to the local breakfast taco place so that the engine would be warm. Easy start. No issues. Once the oil change was done I bolted everything back on and started working on fishing a coax from the rear of the LC to under the passenger seat. I used a coat hanger, fished under the carpet until it popped put where the carpet is split under the seat. No issues. I pulled the coax in, tested it, everything seemed fine. Next I popped the hood and began studying how I could route a #8 pair of wires from the battery to the rear cargo area (might go with a #10 pair). I have a Blue Sea fuse panel coming for that. I popped open the lid on a fuse box that's connected to the positive battery terminal connecter. I noticed there is 100A fuse position that isn't filled. That might be a good place to tap +12V and it would be nice if I could use the factory fuse position.

So that's it, that's all I did today. When I went to start the LC, nothing. The interior lights came on and then went off when I tried to start it. So I checked the battery terminals. Both were tight and clean. I have LED interior light so I didn't think they would have run the battery down but grabbed the charger and connected it. it didn't show any charge current? So I kicked it over to the high current boost for starting and after turning over for a long time it kicked off. The second I pulled the battery charger cables it died. While it was running the tach was jumping and the lights were flashing like a breaker was tripping and then resetting. I put the charger up. The battery was plenty hot. Next I turned the key on and the interior and dash lights would turn on then turn off. That was accompanied by a relay clicking sound.

My guess is that something is shorted and the protection circuit is tripping and resetting. But where? My suspicion is that it's under the seat. That's where the coat hanger got hing up for a little while. I took the amp out a few years ago, maybe some of that wiring shorted?

It could be the box under the hood but I didn't mess with anything under the hood. The box I'm talking about, with the empty 100A fuse slot, is top left in this photo

 

[Mike6158]

Here's what it looks like. It's either an electrical problem or it's possessed. Either way, it won't run.

I pulled the battery + cable off and put a meter with a 10A range inline.
When the poltergeists are having fun the amperage blinks up to 2.0A - 2.5A
When the key is off I see about 20mA. Probably the current that's keeping the anti theft, computer memory, clock, etc alive.
It wasn't the most scientific of tests but it does illustrate the problem pretty well

 

[nissanh]

Did you attach a wire to the fuses located right on the positive terminal? I'll remove it. I think you are powering the electrical circuit in the truck with your aux wire. Also, check what the coat hanger did under the passenger seat.

When I do auxiliary wiring, I'll always tap it to the 12 mm bolt right on the positive terminal and then have a giant fuse. From there I'll run all my wires.

 

[Mike6158]

Nope. I didn't do any electrical work at all. All I did was pull the coax in under the carpet. It almost has to be something under the seat.

 

[nissanh]

May be you blew the 100 amp fuse in the fuse holder inside the positive battery terminal and now the entire circuit is run by the alt-s Alternator-sensor 7.5 amp fuse? Inspect the main 100 amp fuse as well, look through the plastic window. Those are Bussman type fuse so you need to remove the 8 mm bolts on its terminals to remove it.

 

[Mike6158]

That's plausible. I'll check the fuses. I am going to pull the passenger seat and make sure I didn't cause a short there. Something changed between the time I parked it and the time I tried to start it.

 

[2001LC]

Some good suggestion ^^^

Also make sure you give battery posts & clamps a fresh cleaning. Make sure to grease your posts & clamps. White lithium is best, but even Vaseline will do.

Give battery a full charge and make sure it holds the charge, and test load.

Note: A thin layer of oxidation can build on battery posts and cables that aren't greased. This will stop battery from receiving charge.

 

[Mike6158]

Unfortunately I got home too late to pull the passenger seat but I took some time to troubleshoot the fuses and battery.

(1) The battery is in very good shape. Static voltage after about 24 hours of sitting is 11.8V. That included the time I was testing last night. I also put it on one of my Dynaloads. The big one will load the battery to 3000W. I didn't use the big one Again, it's fine.

I then tested the three fuses on the main terminal post. The 7.5A alternator fuse was tested with my meter in continuity mode. It's fine. The 100A and 140A were tested by checking for 11.8VDC on both sides. Both were good. There are some fuses and relays in the box that I tapped on in the video and those appeared to be fine.

I think the problem is going to be under the passenger seat. I didn't touch the electrical anywhere else. Who knows what the hook that I put in the end of the coat hanger (to keep it from poking something) grabbed when I was trying to pull it out.

 

[2001LC]

11.8v is low, I get gremlins at that Voltage.
Good luck!

 

[Mike6158]

It's a little low but the doors were open and closed all day yesterday and there were some other loads so the I expected it to be a little low. I'll charge the battery tomorrow if I get home early enough. The timer on my charger stopped running (mechanical otherwise I'd put it on a trickle charge and leave it overnight). It may cause problems but not like what I'm seeing now. That said, if I charge that battery and it exorcises the poltergeist then I'll gladly come back here and say "that was it!" The Dynaload didn't give me any indication of the battery being weak. BUT... it's not the end all test either. It would take longer to use my "real" battery load tester (complete with charts and graphs to show the results) to test the battery than to charge it but it might be worth hauling it and the laptop out and taking a look.

I've let the LC sit for months without driving it. It's not my daily driver so sometimes (rarely) it sits. When I do that the battery is too low to start the engine (clocks and cpu memory take their toll) but I don't get poltergeist activity from low battery. Did you watch the video? This is more like some kind of current interruptor or something like that.

BTW- one of the things I want to do when I add the circuit in the back is include a place to plug in a solar panel (or other accessory). The solar panel is small and it self regulates so it'll keep the battery topped off. I can't use it now because none of the accessory points are on unless the key is on.

 

[2001LC]

First thing I notice in video was battery post gray and dry.

 

[Mike6158]

I pulled the terminals and cleaned them before I made the video (in the dark with the built in iPhone LED flash / light). I don't ever slather grease on the outside. A thin coat on the mating surfaces works fine. I worked on it for about an hour before I made the video. I cleaned terminals, checked voltage, and I had the battery charger on it. I even tried the 250 boost mode and got it to start but the dash panel and other lights were flickering off and on, relays were clacking, tach was gyrating, running lights were flashing... so I pulled the charger off and it ran for maybe 10s and died.

 

[rampantwolf]

Your deep cycle battery is completely discharged at 11.8V. Try charging it again. If it isn't at least at 12.7V after a full charge you may need to replace it.

A healthy battery should be at 13.3V full charge. A deep cycle battery will range from 12.7V at near full capacity and by the time it hits 12.1V it is already depleted of charge.

 

[Mike6158]

Agreed. I don't know what I was thinking last night. Long day at work. Lots of backroads, driving thru and around high water, turn around and try to find anther route. Fried brain I guess...

 

[Mike6158]

Unfortunately I got home too late to pull the passenger seat but I took some time to troubleshoot the fuses and battery.

(1) The battery is in very good shape. Static voltage after about 24 hours of sitting is 11.8V. That included the time I was testing last night. I also put it on one of my Dynaloads. The big one will load the battery to 3000W. I didn't use the big one Again, it's fine.

I then tested the three fuses on the main terminal post. The 7.5A alternator fuse was tested with my meter in continuity mode. It's fine. The 100A and 140A were tested by checking for 11.8VDC on both sides. Both were good. There are some fuses and relays in the box that I tapped on in the video and those appeared to be fine.

I think the problem is going to be under the passenger seat. I didn't touch the electrical anywhere else. Who knows what the hook that I put in the end of the coat hanger (to keep it from poking something) grabbed when I was trying to pull it out.

After much jacking around i finally just gave up and bought a new battery. Before I get to how that went I'd just like to say that the items in bold, taste a lot like chicken... maybe even crow Battery was good my a**

Before I pulled the Optima I checked it and it was 9.3V. It was 11.6 yesterday. Sooo.... brand new battery... whatever the charge was from the store that's how I installed it (with a little lithium on each terminal). My work truck is a 2017 and I checked it's battery voltage 10m after getting home from about 100 miles of 75mph driving. Ie it's charged. 12.8V. Battery straight from the parts house 12.7V. Now where was I

Oh yeah... I was going to tell you what happened when I tried to start the LC.

Dang thing started like any other day. No weird poltergeists. No strange flashing. It just started like the LC I've come to know (a little better after this) and love. So yeah 1V too low and another dimension opens up and poltergeists take over the electrical.

So that means I was wrr... wrrooo... wrrr... wrrrrr...ooooo...nnnn...guh. (wrong... there... I said it... it was the battery...). I would have never believed it if I hadn't lived it. On to better things...


Seriously... thanks for pointing me in the right direction. I was way out in the weeds on this one. Thankfully I'm short on time so I didn't have time to dismantle the entire vehicle only to find out the da*n battery was toast.

 

[Mike6158]

Your deep cycle battery is completely discharged at 11.8V. Try charging it again. If it isn't at least at 12.7V after a full charge you may need to replace it.

A healthy battery should be at 13.3V full charge. A deep cycle battery will range from 12.7V at near full capacity and by the time it hits 12.1V it is already depleted of charge.

It won't hold a charge. I can't agree with 13.3V. I just checked my work truck after a long drive and it was 12.8V. The truck is brand new, under 10,000 miles, so the battery and charging system should be good.

 

[rampantwolf]

I should clarified my earlier response with, these are approximate numbers as batteries have different designs and will vary. In my world 12.7V and 12.8V are nearly the same. Then again the DC equipment we design deal in voltages up to 3,000V and 15,000 Watt.

The 13.3V is a typical battery voltage before putting it under load, in a resting state. It may be above or below slightly. This can be influenced by the voltage the alternator applies to the battery during the charge cycle. As soon as you put a load on the battery you will find it around 12.7V. In your case 12.8V. Sounds like the battery is functioning properly.

That brings us to a common problem that occurs when we drain the battery accidentally one day. The energy capacity of the car battery diminishes significantly putting stress on the alternator which in turn can prematurely fail.

You can check the voltage of the alternator while the car is running at the battery terminals. You should see up to ~13-14.8V if the alternator is healthy.

 

[rampantwolf]

Lol now having read your earlier response I realize you were getting 12.8V on your "work truck" and that your new battery solved the problem. Please disregard my further troubleshooting tips in previous post. Glad to hear all is good. Cheers