Complicated Electrical Issue

[barrettlexus]

Hello Forum,

I have a 1999 ES300 Coach edition with about 150k miles that has a few issues at the moment but the one that has me stumped is an electrical issue.

Recently, I drove the car into my garage to protect it from the Chicago cold snap and left it there for about two weeks. When I returned to it, the battery was completely drained. I tried jumping it and while would turn over, a bad idle due to an unclean IACV kept making the car die. So, while I trickle charged the battery I cleaned the IACV. The battery became fully charged and would turn over and idle well, but there were an odd set of electrical issues. I have pulled each blade fuse and inspected that they all are working (not blown). I suspect the drained battery has reset something or that a jump/trickle charge might have broken something that I can't find.

Just before typing this post I tried to start the car again (4 days after the full charge via trickle charge) and the battery was completely dead again. It's back on the trickle charge now.

Okay, below is a list of the electrical system items that work and that don't work. Any tips about what to check/change/fix to make them all work would be GREATLY appreciated. When I get through this project, I'll ask about the potential central line hole that's seeming to cause air sensors to keep going bad (more on that later).

Here's what's NOT working:

• Rear tail lights out (no brake lights when I push the brake, no running lights either in the rear)
• Gear shift won't budge out of park (which I know could be related to the brakes issue above but the fuse is good so ...)
• Not a single dashboard light works. By this, I mean:
• The odometer & tachometer needles and display are not lit and not working - the tach doesn't register any RPMs. It sits as though pinned to the bottom of the dash
• The gas gauge is registering empty. This area of the dash and the needle are unlit
• The engine temp gauge is on C, but that could be because it's been very cold here and it could be working. Who knows on that one? This area and needle are unlit too.
• The radio is not working. No sound, no lights, no display, no nothing from it
• The Heat / AC is completely dark. No air blows, no controls work, can't turn it on or off. All the dials are unlit too.
• The electric windows don't work
• The moon roof doesn't work.
• The controls to reposition the seat don't work

Here's what IS working:

• Door ajar chime (which I wish wouldn't work at the moment)
• Interior dome light
• Seat belt icon on dashboard
• The headlights turn on (I didn't try high beams but I suspect they'll work)
• When I turn on the lights, the green light on the dashboard does turn on too
• The green halo light around the key/ignition works
• The horn works

That's what I can recall. If I get it started again I'll provide more if there is more to provide. In the meantime, if you can help with any tips/suggestions I'll be very grateful. I really love this car and want to save it if I can.

Thanks!

Dan

[lenore]

I wonder if you have a ground issue. Check to cable from the battery to chassis and engine. also check the Engine junction box fuses....You didn't cross the charging cables by mistake? There are also fuseable links in the main fuse box under the hood. maybe one of these is blown. To check grounds unhook the battery and measure resistance through the grounds cable to various points. there should be no more than 5 ohms resistance. The battery though charging may have a defective cell, that the instance a real load is put on it causes problems. So Grounds, fuseable links, and battery. Very important when checking grounds, unhook the battery's positive lead. that will give you a better measurement.

[gbhrps]

barrettlexus,

All kinds of strange electrical things crop up when the system is not getting a solid 12 volts from the battery or the alternator. Get that battery charged up and then have it load tested at Pep Boys or similar. It may be the start of your problem. Then, when and if you can get the car started again, get the alternator tested to see if its putting out the 14+ volts its supposed to. It may need replacing, maybe not.

I just went through this same dead battery issue about every two weeks with my wife's 2011 ES350 about a month ago. There are a lot of electrical drains on these cars, from clocks, to security systems, to memory seats and mirrors and radio station presets, etc., that can really drain down a battery quickly in the winter. A new battery solved our issue.

That said, you may find that some mice have gotten into that warm engine bay the last time you parked it. They make a nest under the fuse box and then start chewing wires when they get bored. I had this happen on my diesel dually late last fall. The truck would crank fire and die. $863 in diesel mechanic labour found 14 wires chewed through under the fuse box in the engine bay.

If after you check a few things out that I'ved mentioned, and you still can't get anywhere, you'll need a good independent mechanic to get to the bottom of your issue. Good Luck!

[VBdenny]

Well said Gene. For whatever reason I have found that Lexus vehicles need a lot of juice to operate properly. A slightly low battery can cause major havoc. Again, cold weather WILL damage a discharged battery as they will freeze.

[barrettlexus]

Thanks for the replies! I haven't replied with an update yet because the battery despite, being on a charger for days, now won't charge. I can't even jump it to get it started. Something is amiss!

My question: According to kbb.com the car - if in fair condition - is worth about $1,500, and that's if I can get it running. With a new battery, a repair coming to the central exhaust line (estimated by dealer to be about $2,500) and a lot of time spent looking for a potential short in the electrical system, is it worth putting this amount of money into it?

Either way, I need to fix something so that I can shift the car out of park and into neutral so it can be pushed out of my garage and maybe towed elsewhere. So I have to fix that. But does it make sense to throw money into a new battery if the cost of the rest of the work exceeds the value of the car? I'm trying to separate the romanticism of fixing the car from the reality of the expense.

Thanks, guys. I appreciate your help!

Dan

[barrettlexus]

WAIT! I forgot to connect everything and it turns out the battery is charged and the car is running. Oops. Anyway, I ran two tests with the voltage / ohm meter:

1. Now, I see that the voltage at the battery when the car is idling is only at 11.7 volts. This should be registering over 12 and closer to 13. So, an alternator issue?
2. With the positive lead unhooked and the engine off, I see 0 ohms on the meter. So, it appears to have a good ground and no discharge.

So, I'm googling how to test an alternator and will update the results after I run that test.

Any tips/thoughts in the meantime I'll gladly accept.

Cheers,

Dan

[lenore]

to test alternator, start car and with headlights on, check voltage across the battery, if it measures 13.5 to 14.5 volts DC than the Alternator is charging and functioning....If the voltage measures only 12.6 or less than the alternator is toast. Check battery voltage without starting and it should measure 12.5 or 12.6 volts DC. That is a quick and dirty way to show functioning alternator.

[lenore]

I believe if you get past this electrical problem, your car would be worth much more than you quoted. I sold my RX300 with 187k miles for $6000 three years ago. It was fully functional and in great shape, but had a driveline vibration which turned out to be cradle bearings in the drive shaft to the rear wheels. The Coach edition as you remarked is weird, I didn't think that came out until 2000 or 2001?????

[barrettlexus]

Ok, did you know that a 100A alternator fuse could blow? This box fuse in my car was so dust covered I didn't even see it. Sure enough, when I scraped 15 years of grime off the cover, I could see it was blown. I have started taking apart the fuse box so that I can get to the screws at the bottom of that 100A fuse. However, I can't budge the blasted screws. I feel like I'm about to strip it. I've taken a few photos of the fuse, screws, and fuse box area. Please share any ideas for how to remove this fuse!

Oh, and here are the results of my alternator test (here's a great video for how to test your alternator https://www.youtube.com/watch?v=LGB6ZEjGm7Q )

• Battery at rest, car not running and nothing turned on the battery shows 11.7 volts
• With the car running and the alternator spinning, the battery registered about 12.2 volts (not sure how this change in voltage at the battery even happens when the fuse was blown...)
• With the headlights turned on the battery shows 11.9 volts
• Lights off again and the battery showed 12.2
• After 30 seconds of the car turned off the battery returned to 11.6 volts and held it there
• On the voltage drop test I showed .02 but it didn't change on either the positive or negative of the battery, nor did it change when I revved the engine.

Thanks a ton for all the help so far!

Dan

Here's a legend for the pics:

Top left one needs to be rotated to the right 90 degrees. Its a shot of the fuse box take from the middle of the engine (I removed the battery). It's from mid compartment looking to the driver's side front wheel. Just the side of the fuse box with it pulled out of its seat.

Top right one is top-down view of the fuse box. You can see the top left of that pic shows the blown 100A fuse. The clear 100A cover is in the photo too

Bottom left one is the 100A fuse pulled out of the compartment. The two red screws here are the ones causing me headaches.

Bottom right one is a top down view of the fuse box that's located inside the hood at from left (driver's side).

[lenore]

First get the alternator fuse fixed. Your battery voltage is not good. It may be going bad.....my test above are what you will need.

[barrettlexus]

Update: I replaced the 100A alternator fuse (which was blown), reconnected the battery, and it turned right over. Voltage at the battery terminals with the car running (nothing turned on though) is now at 14.2 volts (where it was 12.2 with the fuse blown). So, seems like the alternator is good and charging the battery now. Also, all the electrical issues I mentioned in the original post seem to have been fixed, meaning that all of the above electrical items that weren't working are now working.

In the meantime, I also found this string on another website that appears to speak to the same issue: http://www.justanswer.com/lexus/5x7op-lexus-es300-hi-99-es300-battery-replaced.html

So, the electrical issues being fixed is the good news. The bad news is that with everything working I can now see the blinking check engine light that was the original issue before all this other electrical fun started. That'll be another post.

Thanks, everyone, for all the information and support. It's been great to have your help and input along the way.

Cheers,

Dan

[lenore]

yea success and no alternator replacement....Ok on to next issue...

[barrettlexus]

Quick Success Story:

My car works! After I replaced the blown alternator fuse I mentioned above, the electrical system worked like a charm. Battery is fully charged, alternator is kicking out the right juice and all the electrical is working. This is important because I suspect that an inadequate electrical supply might have made the computer kick out 'interesting' (read: wrong) error codes. Before I fixed electrical issue, the local Lexus dealer told me he suspected I had a hole in the central exhaust, which was letting inappropriate air flows be detected by the air sensor, causing the engine to sputter and run rough, like it was misfiring. After the electrical fix, it turned out that I was having an issue with a cylinder wire harness. I hooked the car up to a scanner and the readings were very odd. The engine would run smooth, then choke and sputter and run very rough (obvious misfiring), then run fine. Cylinder 1 was the apparent culprit. With the engine running, I jiggled the wire harness and sure enough, it caused the same sputtering issue. I had to rebuild the wire harness (I couldn't find it for sale anywhere) and replace it. Since then, no issues and the car runs great. I've had it running for about two weeks and about 100 miles and no problems.

Thanks to everyone for their help and support! Now, I'm off to reach the 200k plateau!

Cheers,
Dan

[lenore]

Thank you so much for the feedback, You never know when this problem could happen to somebody else, and you had the solutions...

[elpossum]

I own identical vehicle - '99, Coach edition, even about the same mileage, around 158K. Constant electrical problems. Battery dies in a few days of non-use. Will replace alternator and see if that helps - did you go new or used on your alternator and what part did you replace it with? Thanks!

[Lightupyrday]

On 3/5/2015 at 12:31 PM, lenore said:

I wonder if you have a ground issue. Check to cable from the battery to chassis and engine. also check the Engine junction box fuses....You didn't cross the charging cables by mistake? There are also fuseable links in the main fuse box under the hood. maybe one of these is blown. To check grounds unhook the battery and measure resistance through the grounds cable to various points. there should be no more than 5 ohms resistance. The battery though charging may have a defective cell, that the instance a real load is put on it causes problems. So Grounds, fuseable links, and battery. Very important when checking grounds, unhook the battery's positive lead. that will give you a better measurement.

I know this is a late comment, but I just looked here for some info on my Lexus.  I'm a retired electronic engineer in medical x-ray, CT etc. and deal with both high voltage and low voltage/high current circuits.  I wonder if that quote of 5 ohms should have been <0.5 ohms, as at 12 volts,  5 ohms is a huge amount of resistance and a starter motor would not turn over.   Even headlights would draw enough current to severely drop the voltage.  The main battery leads + and -  are heavy (25mm2 Copper) to reduce resistance.  I look for around 0.01 ohm max to the chassis or starter motor.  

Two headlamps at 65W (130w) will draw 10.88 Amps at 12V  ( 130/12 = 10.88A)   The resistance of the two headlamps is calculated by R = E ÷ I    (E =Volts, I = Amps)  Therefore 12v / 10.88  =  1.1 ohm.  Therefore even a 1 ohm resistance in the wiring will halve the voltage at the headlights and a 5 ohm resistance will hardly make them glow.  The lower the voltage the more important resistance is.  This is why AC mains is supplied for great distances at very high voltages- Here in New Zealand we use 230V which can operate with less copper in the wires than in USA at 120V  A starter motor may draw say 100Amps (100 x 12 volts = 1200 Watts) and the starter motor will have a resistance of  0.12 ohms.  Thus even 0.1 ohm resistance in the wires will approximately halve the voltage and may not allow the starter to turn over.  Meanwhile a lot of heat is being generated in the starter leads. 

I have found there is much confusion in understanding the relationships between Resistance; Watts; Amps and Voltage even in auto and domestic electrical trades.  Once you get your head around it, it becomes basic nature.     I learned this analogy at College in the 60's -  "A Volt chased an Amp thru an Ohm"  Likewise, 10 volts will chase 10 Amps thru 1 ohm; and,,, 10 volts will chase 1 Amp through 10 Ohms.  The formulas are available online.