Complete electronics shut down

[scot850]

I appreciate you are in CA?, but do you do a lot of short trips using lights, heater/AC or the likes?

Up here, if we do that a lot, the car battery does not get the opportunity to recharge enough between uses of the car and can drain/strain the battery over time. My wife used to drive to the train station, but in winter here it is dark and cold going to/from the station. I had to fit a trickle charger to prevent the random no starts.

This does not mean the battery should only last 2.5 years. The battery in that car lasted 10 years in Canada!

Have you done a parasitic current draw test on the car to see if something is drawing the battery down between uses? My old 00 V70R
has an alarm system that draws the battery down over a couple of weeks, so over the winter I connect a trickle charger/maintainer.

Neil

[imaV70Rdriver]

Thanks Neil. Yes indeed, a Canadian located in California. I would agree with your suspicions. Mostly short trips around town with the lights on, with a “once or twice monthly” drive of 50 miles or so. Often the car sits for a week without being driven.

I just phoned AutoZone and was told that my battery is still under warranty. I’ll take it in to get tested and update this post.

[packetfire]

There is a fuse on the cable that connects to positive battery terminal of many v70s.
No, it is NOT documented anywhere in the wiring diagrams.
Look at the battery connections, and follow that red cable, as you never know what kludges have been attempted by prior owners, and you have a v70R, a kludge magnet.

[scot850]

Well that is a new one to me. I know on P3's there is a fusible link that becomes a pain after multiple battery connector removals, but not on the P2. Thanks, now I'll have to go look..............!



Appreciate the learning, every day is a learning experience!

Thanks,

Neil.

[imaV70Rdriver]

AutoZone tested and charged the battery. Said it’s good.
I took it home and connected it with battery cables. Nothing. I connected my battery tester and the pics are attached.
The setup…

Readings while connected…

Readings disconnected from car…

I also connected a load tester which read over 800 CCA after a 10 second load test, and measured 12.5 volts and holding steady after removing the load.

If anyone who knows where the possible fuse might be located, please say. Do I need to remove the floor panels behind the back seats to get to it?

I’d greatly appreciate feedback regarding what I might check next. Tks.

[imaV70Rdriver]

No comments on my last post, eh!
The 2.5 year old AGM battery reads good/recharge when not connected to anything. But if I connect something , like either the car or jumper cables and take a reading from the other ends , it reads “replace battery”.
Does anyone know if this is normal?
I’m thinking about buying this…
https://www.amazon.com/dp/B08G3M697M?re ... i_atc&th=1
Any thoughts?

[imaV70Rdriver]

Happy New Year everyone. I have an update.
The Fixx song, “one thing leads to another” is stuck in my head as I write this.
As mentioned, I took my battery (still under warranty) to one of my local Autozone stores where they put it on the battery tester. They said the battery was good but needed to be charged. It was near closing time so I left it overnight. When I came to pick it up, the guy who I left it with was not working, and another employee checked it and said it was 85% charged. He didn’t know if it was put on the charger at all. Meanwhile, I had located a “constant current, constant voltage” battery charger in my garage that I used for a 12 volt Li battery, and having discovered that my AGM battery could be charged with this type of charger, I took the battery home and left it to charge overnight. Finally, after about 14 hours, the charger light went green. I was hoping for all my problems to be solved, but no such luck. There was no response from the car, still completely dead, no interior lights, and no way to move the seat back from the forward position it was in when it died on my wife. It was very difficult to connect VIDA and uncomfortable to say the least. Every module was RED! I had the charger connected while connected to VIDA, and left it connected to the battery and went for a walk with the dog. When I got back (about an hour later) the tailgate was locked! When I opened the drivers door, I was pleasantly greeted with the familiar “bing, bing”, and my interior lights were on, and the seat motor had power. I tried starting the car, it ran but sounded like it was running on three cylinders, the roughest I’ve ever heard a car run. I reconnected VIDA, updated it, cleared all faults, and all seemed okay, except the dash gauges still didn’t work (a DIM failure I suspect, and probably an unrelated problem). I’m not super familiar with VIDA (I don’t find it very intuitive) so I futzed around checking various modules and tried to figure out the gauge issue but saw no faults. I saw a YT video on how to check the battery under load while starting the car, and noticed a low reading of 8.2volts on the meter which is lower than the stated minimum of 9.6 volts. This had me thinking that the battery was actually bad even though all the tests I had done indicated that it was good, which included the Autozone test, and my Schumacher BT-100 test (maybe this tester doesn’t work on AGM batteries?, Idk). Then while I was watching the meter and revving the engine to see what the voltage was (to see that the alternator was charging properly, which read 14.6v) the car simply died, and the voltmeter read 3.0v. I phoned a different Autozone store and told them of my issues, and the employee said just to bring it in. Their battery tester wasn’t working but they gave me a brand new battery. Everything except the dash gauges worked, so with some apprehension I drove around the block, then around the neighborhood, and I thought that was it, problems solved. But no, there’s more, of course.
I’ve had the car for 10 years (bought it at 109k, and now it’s at 184k miles). Shortly after buying it, the alarm went off out of the blue, and the locks wouldn’t open with the fob or the key, so clambering over the seats (back door locked and tailgate locked) while the neighbors wondered WTF I was doing, I finally got the battery disconnected (oblivious to the fact that I could have pulled the alarm fuse). I said “that will NEVER happen again!” and I pulled out the alarm fuse, which remains out to this day. I also found that I had the well known issue of the broken wires leading to the tailgate, and fixed them, suspecting they were the cause of the battery drain and the alarm sounding. At some point the panel with the light in the roof (near the tailgate) started falling down so I just removed it, leaving no light when the tailgate was open (some people have said that their light was turning on and off intermittently while seeing a “tailgate open” warning on the DIM, likely the same wiring harness issue mentioned above). Anyway, everything seemed fine for a few days, but then the alarm lights were flashing again, out of the blue. The siren fuse was out, as mentioned, but the red light on the dash near the windshield would still blink on and off, “pretending” the alarm was on to passersby. But this light flashed rapidly when I unlocked the door, and I’m sure the alarm would have been screaming had the fuse not been removed. Inside the car, when I put the key in the ignition, the “tailgate open” warning was lit, but it was tightly closed. I think now that I’ve had an intermittent wiring issue related to the “tailgate open”, which caused the alarm to start, but how would I know because I had removed the fuse! So it seems that the alarm was going, on and off, intermittently and out of the blue, for who knows how long. Last night, out of the blue, it happened again. The car had been parked for a few hours with no alarm or flashing lights, but my son noticed it start flashing for no apparent reason. By the time I got my shoes on, the flashing had stopped. Thinking about this, I wondered if the alarm sounds for a period of time, and then stops, then starts again, over and over, draining (and eventually killing the battery). The only way I could get it to stop was to disconnect the battery, which is kind of a bummer because I need to get the car smogged, and disconnecting the battery causes the “ready” codes to reset to “incomplete”. But I still need to get the DIM repaired anyway (I looked on eBay and there are companies that will repair my original with a lifetime warranty, or for as long as I own the car, for the same price as a used one. So that’s next).
As for the odd readings from the Foxwell battery analyzer (oddly, also called “BT100”) in the photos above, it seems that the device only reads the battery properly when connected directly to the battery, because it reads “replace battery” (even with a brand new battery) when connected to the +ve terminal under the hood, but who knew.
Next things to do… get the DIM repaired, and chase down the (probable) wiring issue related to the intermittent “tailgate open”.

[imaV70Rdriver]

Update. I had made some repairs to the tailgate wiring a few years ago, soldered and electrical taped. The other day I found a previously soldered wire, one of the three yellow wires (hidden behind the thinner black wire in this photo), was no longer solid (when I removed the tape to check the connections), and the connection separated as I removed the tape. I have now decided to replace the wiring harness altogether using part number 8645685, which is on its way.

I did, in the meantime, reconnect the yellow wire. I still had the “tailgate open” message once or twice shortly after doing that, but not for the last few days. I’ve also been locking the doors without setting the alarm, to avoid the light on the dashboard near the windshield from flashing. I haven’t therefore had the alarm lights on the outside of the car flashing, which I think was draining the battery.

I might add a post to the thread about the tailgate wiring when I change the harness, but it does seem that all my “complete electronics shut down” issues were, as suspected early on, battery related. This has been a long and frustrating experience to say the least. I hope some part of this post will save someone much angst. Cheers all.

[jonesg]

ABscate advised a voltmeter, I would go better and get an automotive meter, $35 ebay.
Read v at the battery , then read at the terminals in the engine bay, any appreciable drop , as shown on the foxwell, and I would run my own aux temporary wire to see if that clears up any problems.
I'd disconnect the battery and run resistence checks on the 12v feed from the battery to the engine bay.

[vtl]

Update. I had made some repairs to the tailgate wiring a few years ago, soldered and electrical taped. The other day I found a previously soldered wire, one of the three yellow wires (hidden behind the thinner black wire in this photo), was no longer solid (when I removed the tape to check the connections), and the connection separated as I removed the tape. I have now decided to replace the wiring harness altogether using part number 8645685, which is on its way.

I did, in the meantime, reconnect the yellow wire. I still had the “tailgate open” message once or twice shortly after doing that, but not for the last few days. I’ve also been locking the doors without setting the alarm, to avoid the light on the dashboard near the windshield from flashing. I haven’t therefore had the alarm lights on the outside of the car flashing, which I think was draining the battery.

I might add a post to the thread about the tailgate wiring when I change the harness, but it does seem that all my “complete electronics shut down” issues were, as suspected early on, battery related. This has been a long and frustrating experience to say the least. I hope some part of this post will save someone much angst. Cheers all.

I'm sorry, this repair looks subpar If you ever have to do it again, better use crimping electrically insulated connectors. They are shock-proof, too. If soldering is absolutely unavoidable, use lead solder and do solder joints at offset to each other. This way they don't short circuit when you electric tape eventually compromises.

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