Oh, and my day got away from me and I didn't get a chance to work on the car. I'll do it on Sunday.

 

 

I (almost) forgot that I was spending the day with my wife yesterday. No work on the car. However... I've been putting the battery on the CTEK every night. Yesterday, we drove 40+ miles to a concert. No problems on re-start. Drove over to Seattle, parked, ate, shopped. No problems on re-start. Drove back home, made a pitstop, parked, shopped. No problems on re-start.

I wonder if the "Recondition" (equalize) setting on the charger is slowly bringing this battery back to life. I'm still going to test with another battery I have, but I think I need to re-baseline the discharge behavior of this battery.

I'm looking at the NAPA Legend Pro or Premium batteries (I can't tell the difference from looking at the NAPA web site). I don't think I'll get another AGM (for the Jag) after what I've been reading in my research.

Ken

 

Yeah, like somehow time spent with "family" is more important than a bunch of strangers on the internet...

 

I will submit, for the record, that you described yourself as "strange"

Instead of mucking about with the other battery, I decided "f*** it" and went to NAPA and got a new battery. Went with the Legend Pro. NOT-AGM. Good-ole flooded wet cell.

Votage was a little low going in - 12.34v. It was up past 12.6v once I got to work. I'll see what it's at when I return this evening to the parking garage.

One thing that I discovered, quite by accident, is that the OBD port is powered even when the key is off/out of the ignition. I plugged in my Foxwell, and it powered right up, even though the car keys were in my pocket. This unit replaces/augments my Bluetooth scan tool, which I've left plugged in for months/over a year since I replaced my old one. I haven't traced down the circuit, but it might be the source of the extra 40mA drain I saw in my quiescent drain checks.

So, possibly two good pieces of news... We'll see.

Ken

 

I will second the motion. All in favor, say "Aye!"


Good call on the battery. I think somebody mentioned recently (in this thread?) that our cars don't take kindly to AGM batteries, due to a higher charging voltage required or something like that. Did I get that right? Hopefully I will be quickly corrected if less correct than usual.

​​​​​​​Don't forget to give the new battery a good charge overnight on the charger. New batteries are usually not fully charged when purchased, as you have discovered. Unfortunately this means you'd have to wait another day to see how she does after sitting overnight untended.

My '02 is like that, too. I leave my Bluetooth transmitter plugged into the OBD port all the time with no ill effect. A little LED glows on the transmitter, so I know it always has power. I still have to turn on the ignition for my scanner app to communicate with the computer, though. Unlike later models, my car is not very picky about prestart voltage, so that slight drain doesn't seem to be a problem. The constant power to the OBD port must have been just a convenient place to supply voltage, and was never really designed for full-time use. If so, the designers of the OBD protocol kept it simple and never even thought to switch it off.

​​​​​​​Now you have me wondering if your Bluetooth transmitter was periodically powering up, either by design or due to a defect. Please refresh my memory about your quiescent drain test setup. Did the meter have the means to record an intermittent high load, or was it only live data from when you happened to have been looking? Were you measuring all loads, such as at the cable right at the battery? Or were you measuring further away, such as at a point downstream of a harness split? I vaguely remember the latter giving you problems. Mostly just wondering if your test conditions would have caught a sporadic drain at the OBD port.

 

Use an ordinary lead acid battery and the car's vent tube. Smart charger is only designed for those (plenty good enough life if used properly and affordable).

 

Yep, I charged the new battery yesterday evening, and after the charger indicated it was in float mode, I took it off the charger to see where the voltage settled. 12.79v - so that's quite promising. After I hooked it up to the car this morning, I measured about a 3A draw, and voltage of 12.55v. Car started fine, no undervolt warnings. After arrival at work, it read 12.52v - but it usually goes up as the car sits. I find conflicting information about what voltage corresponds to 100% SoC. It's either 12.8 or 12.6v. If 12.6, then we're doing good so far. If 12.8v, then I have a charging problem.

In parallel to charging my new battery, I did another rundown test on the "WillItLast" battery. Started by topping up its charge and hooking up my 4A load. It dropped from 12.8v to 12.5v in the first 25 minutes, but then leveled out and was losing .01v every 20min, which corresponds exactly to the math. Since this battery is an AGM and should be capable of both faster charging and deeper discharge, I'm going to keep it and put it into service as a UPS battery.

To answer your questions:
1. My drain test setup consisted of a length of, essentially two-conductor speaker wire - with the ends on each side stripped and twisted together to get a wire with effectively a heavier gauge. This was wrapped around the Bat+ post and secured, run out the trunk and back to the + battery cable clamp, forming a loop outside the car which I could easily measure with my amp clamp. This guaranteed I was measuring current upstream of the place where the + feed splits.

2. I was checking the drain every 15 minutes until it dropped, then every hour after that. My meter doesn't support min/max or logging. I'm getting another one that does all of that and then some.

Ken

 

I did a deep-discharge on the "WillItLast" AGM last night. Ran it down to 11.85v. The CTEK wouldn't charge it after that. It would go through the steps and claim victory while the battery was still only 12.05v. I used my ShipToShore 15A charger on it (which also has an AGM mode), to bring it up to 12.5v, then the CTEK would actually start charging it.

Strange, eh?

Regarding the new battery, Day 1 after a full charge was good. It was 12.52v upon arrival, and 12.65v at the end of the day. I think this means the battery got a good, deep saturation charge, and the car's charge circuit is doing fine.

I'm working from home today, but I have some errands later (lots of start and stop). We'll see how it does with the "liquor store robbery" scenario. For those new to the thread, no, I'm not robbing liquor stores

I left my wireless OBD reader plugged in overnight as a test. I'll go check it in a bit to see how that affected the overnight drain.

Ken

 

Any updates? I'm on pins and needles.

And can you pick me up a bottle of Thunderbird, too? Thanks.

 

I'm sad to say that it appears the new NAPA battery did not solve the problem. I didn't actually drive the car on Friday, and the battery had leaked down from 12.48v on Friday at 4pm, to 12.44v at Saturday noon. Fired up without the EPB fault, and I drove roughly 20mi, and spent about 3 hours there until starting it back up and meeting my family at the movie theater back in town where I live. Upon return to my car after the movie (Black Panther! it was great), the EPB faulted on me. I've been bypassing the parkbrake on shutdown because I don't trust it, so I was able to drive away without having to hotwire the EPB motors.

I put the battery on the charger, disconnected from the car, that evening. I put the CTEK on winter mode, which charges to a little higher voltage to generate just a little heat in the battery. This morning, the battery, directly off the charger (which was in float mode), read 13.4v. After reconnecting the battery cable and tightening it, the voltage had dropped to 12.52v. I also read 3.5A at the negative cable using my amp-clamp. When I got to work this morning, I sat in the car for a couple minutes and checked my work email, then checked the battery - 12.44v.

I fell pretty confident that battery as a root cause has been ruled out. I have a hard time believing that this is a quiescent drain problem, since the voltage drop over the course of a day and a half was only .04v. Plus, my measured "sleep" drain was only 60mA. High, yes, but not high enough to flatten a battery in 2 days. PLUS, the voltage after starting with a fully topped-up battery, driving to work and sitting in the car for 2 minutes, should not have been 12.4v.

So, operating draw is too much for the charging system to cope with?

Ken

 

 

No, it's was disconnected Saturday. I'm going to leave it disconnected now as I work through the drain/charging issue to rule it out.

Ken

 

​​​​​​Ken, I've got to admit this one has me stumped, and I chase sparks for a living.

Please see post #41 for my thoughts on excess "operating draw". It's not really a thing I've ever seen tested. If the operating draw exceeded what the alternator can supply, the system voltage would dip down, but you're seeing a nice solid 13.5v. EDIT: This would apply to low alternator output and/or excessive "operating draw".

It may be worthwhile to have the charging system professionally tested. Instead of just measuring voltage, the shop will have a load bank that makes the alternator work at its full capacity. They'll measure the amp flow in addition to the voltage, for a very comprehensive assessment of the alternator.

I still wonder about quiescent drain. You've got 60mA, when the limit is 30. That small extra amount shouldn't affect the liquor store robbery scenario, though. Maybe that 60mA is indicative of an intermittent higher load, but the peaks aren't being captured? It's a long shot, but I wonder what might turn up with a thorough quiescent drain test using a min/max recording meter.

And to add to the confusion, per post #54, the EPB faults didn't start until the battery was changed for another reason.

Call me confused.

 

Okay, Ken, I'm hot on the trail of something. I got to wondering why the problem was so intermittent. The liquor store robbery scenario seemed to be the most troublesome, right? That is, a restart within a few minutes of shutting down. What changes, so you only get the fault sometimes, but not always?

From Troubleshooting 101, moving parts are more suspect than fixed connections. How about the ignition switch? Two possibilities there:

1) When you release the key from START to RUN, it may not always spring back 100% to the RUN position. The ignition switch has multiple poles, and not all of them may be making a good connection all of the time via the spring-loaded return action. My old pickup previously did this on occasion. When I released the key from START, the engine continued to run just fine, but sometimes the heater fan didn't operate. If I jiggled the key, the fan came back to life. I've since replaced the ignition switch and all is well again. So next time you get the fault, try jiggling the key and see if that helps. Once the fault is set, you may need to restart the engine to clear it, so perhaps for a few days you can assist the key back to RUN after each start, and see if that helps.

2) That pole of the ignition switch has high resistance. The fault isn't tied to the spring-loaded return action, it's just some arcing at the contacts creating the hit or miss condition.

For either situation, the fix is to replace the ignition switch.

If the internals of the switch are not making a good connection, it will get warm in use, further increasing the resistance, in turn increasing the resistance in a spiral. So if my theory holds water, when the car has sat overnight, the switch is cool and level of resistance isn't enough to drop the voltage low enough to set the fault. Drive for a while, especially with max electrical load, and the switch warms up, increasing the resistance. You stop to knock over a liquor store, and the switch is still warm, the resistance is high, and voltage to the module is now low enough to set the fault.

You can test this theory very easily. Open your wiring diagram and scroll down to section 01.5:


http://www.jagrepair.com/images/Auto...cal-2005on.pdf


Note pin FC18-7 on the ignition switch, and how it feeds multiple circuits via splice FCS6. One wire feeds switched battery voltage to pin CA266-9 at the parking brake module.

Also note how the top wire at splice FCS6 goes to fuse F3 in the primary junction fuse box (front US passenger footwell). Here's where it gets interesting, at least to me... Fuse 3 powers the Dynamic Stability Control system and the Cruise Control. Those are the other two common faults everybody seems to get in addition to the parking brake fault.

So here's the easy way to test the ignition switch. With the engine running, turn on the normal electrical loads you have while driving, seat heaters, headlights, defrost, etc. At the battery, connect your meter's (+) lead to the (+) post. At the primary junction fuse box (US passenger footwell), connect the meter's (-) lead to fuse F3. Do not remove the fuse, but just touch one of the little recessed spots in the head of the fuse. Set your meter to DCV, and select the lowest scale possible without exceeding the range.

If the switch and all associated wiring are in good condition, the maximum value you should see is 0.5VDC. This is a test of the voltage drop between the two points. The closer to 0.0 the better, but 0.5 is a practical limit. If you're not familiar with a voltage drop test, the reading only matters with the circuit UNDER LOAD, so ignore any reading you may get with the ignition switch off. Look at the wiring diagram again, and you'll see how that test connection should also include the feed to the parking brake module, via splice FCS6. If your reading UNDER LOAD is above 0.5VDC, your most likely culprit is the ignition switch. Take that one reading, and let us know what you find. If out of limits, I can walk you through how to narrow down the results to be 100% positive the switch is at fault and not the wiring.

 

I just played with the key on my '02. After letting the key spring back from START to RUN, I could still turn the key back about another 30 degrees. Can anybody with a late model confirm if you'd normally see this, too?

 

Ken, Ken, have you abandoned us? Have you found some other forum that can actually help, instead of just offering vague theories?

Or are you cooling your heels in jail, after a jammed parking brake foiled your escape after knocking over yet another liquor store? If so, this jail survival guide should help:

 

Yeah Ken...get back here and report a fix. The wife just came in from an attempted trip in the 05 and reported it wouldn't let her go something something park brake and she tried to release it but popped the bonnet instead and didn't know how to close that, nor release the park brake!

Upon closer inspection. I found Park Brake Fault and Cruise unavailable, with Park Brake Engaged. Later, under closer inspection, I found the battery voltage at 12.06 and water in the boot. WDS reported no communication with the Park Brake module and a code in the ECM. With Karl as my witness, I thought for sure I could remember it..and didn't snap a pic....but I can't, couldn't...whatever. It was P1754 or maybe P1755 or possibly P15somethingsomething.

Car has been sitting unmolested since last Wed, and short 5-miler runs at a time before that. I also noted when I popped the bootlid, that the solar charger had been disconnected from the system.

So please hurry up and sort this on your end so I can just effect a fix without Karl driving me through every cockamaimee troubleshooting scheme he can dream up!

No Jon...I haven't forgotten your Park Brake adventure...but haven't had time yet to go review your thread.

 

Cockamamie, huh? Well I just may have a surefire fix for you, but now I'm not going to tell you. So there! Maybe I'll give you one little hint. I've been tracking instances of freak sunspot activity, and have noticed a correlation with the timing of parking brake faults...

You know, if Ken has forsaken his own thread, maybe we can trash it and therefore shame him into trying to clean up the mess. And what better way than (drumroll please) Dad jokes? I'll start:


What do you call a dog with no legs?

 

Doesn't matter what you call him....he can't come!

So far....the only performance I can claim is: Ran a drop-cord out to the car and fit the VDC Electronics battery-minder charger to it. Hoping not to have to do the arduous research on threads I know are in here explaining how to hotwire the park brake motor to release.....but if I do, so be it...will probably attempt the batt disconnect first though. Anywho....once released I'll get it up to the shop and get it dried out and try to sort it. Need to swap out climate-control heads anyway as manual-defrost mode has become cantankerous of late. And by cantankerous...I mean pretty much doesn't work....the wife claims it will if she nags the defrost button like she does me...and I understand that...but a press or two from me and it doesn't light and nothing changes in the HVAC sys.