Wiper motor draining battery while driving?

 

By by the way, @Theron, thanks for leaving some flares in the trunk. Really. Very helpful. I ordered replacements right away from the side of the road.

Drive to your nearest auto parts store and have them do a charging test.

Probably alternator
>

I have a multimeter. Is this simple to diagnose myself?

Ahh, no! Glad you were safe. 

It's always possible you battery just had a bad cell give up. But you should put a volt meter on the battery while it's running and make sure your alternator is outputting the right voltage.  It should be about 13-13.5 volts at idle, closer to 13.8 to 14.2 with the engine revving.   Oh and make sure your belt didn't slip of like you had before. That would keep the alternator from turning.  If you are driving, even with wiper motors on it shouldn't be a problem.

You can get a cheap multi-meter for under $20. Just set it to DCV or DCV20.
http://amzn.to/2gl5vKP

I found a video that shows the basic process.
https://youtu.be/Bzz7P3qNHcE
-=theron

Off: 12.00v (expected 12.5-12.8v)

Idle: 11.96v (expected 13.8-14.8v)

Idle with load (lights on): 11.52v (expected slight 0.5v dip, then jump back to 13.8-14.8v. I noticed a dip, but nothing more)

Time to go visit Tony in Auburn, CA for a new alternator? @Terry Nuckels, @RocklinMike

What should I expect this to cost (parts & labor & time)?

Ryan:  CIP1 has them on sale, currently:

http://www2.cip1.com/ProductDe...ductCode=BOS%2DAL82N

Figure $160 for the alternator (go for a genuine Bosch or a rebuilt Bosch - DON'T get the cheap Asian reproductions)  and another $100-150 to put it in, maybe more labor if it becomes a PITA to maneuver the fan shroud around to get it out/in.

Thanks @Gordon Nichols. Very helpful.

 

Ryan, Tony will get you fixed.

He'll know right away if the alternator needs to be replaced (or the belt tightened or ???) and he'll know the best alternator to use and have a good source for one, too.

I wonder if you didn't shake a wire or two loose when you were bashing around in the foothills. Half the electrical problems with these cars are caused by loose or corroded connections.

 

I think it's a bad cell in the battery. The auto parts place will test the alternator too tho.

I'm with Ed - especially if battery is 4-5+ years old.

A good electrical test places a current stress on the system, much more than a voltmeter can show you (although a voltmeter is a good first step).  Some of the FLAPS around here have them, typically a Sun or Autometer tester - A hand-held unit with the typical battery jumper cables on it and a meter or read-out.  They're expensive but really do a good job.

They typically use a big, honkin resistor to load the system at a known rate to then see how well the battery AND the charging circuit is working.  They can also tell you the max output of the alternator in amps (always a handy number to have in your notes).

Given the voltage numbers you posted, though, I would first suspect the alternator (since the low-load voltage isn't up to snuff), but it's always a good idea, since it's all part of the same test, to have a full system stress test done and THAT will tell you whether the battery cells are AOK.  Usually it's part of the alternator test, anyway.

Mitch's comment makes the most sense - often the folks at places like "Autozone" aren't experienced enough (or have even worked there long enough) to unnerstan what the tool is telling them, so go to someone experienced whom you trust.

Good luck!

Word....and they'll do it for free....

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> A good electrical test places a current stress on the system, much more than a voltmeter can show you (although a voltmeter is a good first step). Some of the FLAPS around here have them, typically a Sun or Autometer tester - A hand-held unit with the typical battery jumper cables on it and a meter or read-out. They're expensive but really do a good job.
>
> They typically use a big, honkin resistor to load the system at a known rate to then see how well the battery AND the charging circuit is working. They can also tell you the max output of the alternator in amps (always a handy number to have in your notes).
>
> Given the voltage numbers you posted, though, I would first suspect the alternator (since the low-load voltage isn't up to snuff), but it's always a good idea, since it's all part of the same test, to have a full system stress test done and THAT will tell you whether the battery cells are AOK. Usually it's part of the alternator test, anyway.
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I replaced the battery first. It was almost 7 years old. I also bought a small 1000A lithium jumper just in case.

I'm doing a fair bit of traveling so I'm not able to drive much anyway. I'll see how far this solution gets me.

Thanks for all your help. So far the madness hasn't been that maddening. I'd like to keep it that way.

Ryan, that's a band aid. You need to find out if the alternator is good or not. Otherwise, this will happen again. Wipers really aren't that heavy a current draw.

DannyP posted:

Ryan, that's a band aid. You need to find out if the alternator is good or not. Otherwise, this will happen again. Wipers really aren't that heavy a current draw.

Just want to take a moment to agree with @DannyP here. New battery has been fine for about 6 weeks, but alternator not keeping it charged. I charged it overnight and it felt like a new car! New alternator comes tomorrow. Thanks for all the help guys.

Hey all. Got some new data. My new alternator is in the garage (AMZN had it for $150!) and ready to install should I need it, but I'm hoping for a bit of feedback first.

 

Test run after driving ~100 miles avg 75mph

Battery
Off 13.04v
Idle 13.04v (climbing super slowly 0.01 every few seconds)
Load (lights on) 12.5v (falling slowly 0.01 every few seconds)

Alternator (B+ to frame)
Off 12.70v
On 13.00v
Load 12.60v

What do you make of this? The symptoms that started my concerns were:

1) dash lights were growing dim with lights on

2) car needed a jump to start up a few times in a row (I borrowed a charger to make sure the battery was charged fully 2 nights ago)

3) turn signals stopped blinking. Just stay on (I fluttered it to indicate turns)  and now they don't even indicate they are on on the dash. I look for the reflection on the car in front.

4) car ran a bit sluggish before I charged up the battery again

All that said, I just drove a long way at a decent clip and it ran well. Daytime, no lights though.

The battery is 6wks old, so it's not the battery.

 

Voltage regulator, or alternator, probably.

 

What Ed said.

If B+ is only 13V when running, you're not likely charging a battery that's at 13V to begin with.

Just checked mine, and (four-year-old) battery at rest is 13.6V. B+ is 14.6V running.

Double-check all connections first. At alternator, battery, and the whole ground path from the battery back to the alternator. Pull cable ends, check for clean bare metal, reconnect.

An auto electrics dude should be able to test the alternator and voltage regulator without yanking them, but I think your numbers point to the charging circuit.

 

 

Yes @Sacto Mitch I dropped by my neighbor (who's fixing up his 356 coupe) to talk it through as well. I had a speedster full of groceries so I couldn't stay long, but he recommended the same. Said it's less likely the alternator and more likely junk along the ground line. I'll get underneath soon enough to trace the line, clear the gunk and see if my symptoms are resolved. Thanks for your help. Back again when I know more.

I had something similar a few years ago, weird voltages and hard starting, turned out to be a corroded ground strap from transaxle to pan.

I'm still thinking you'll be putting that new alternator in. 

I had a similar problem a few years ago. The voltage regulator was the problem. Of course it is inside the alternator. I used a Chinese alternator because I could not get a Bosch quickly. The knock off died a couple of months later so went back to a new Bosch. I leave a trickle charger on the battery when not driving on a regular basis. My car is stored at a friend's for the winter. I have started it a couple of times with no problems. I did put in the highest amp battery that would fit last time I replaced it. 

 

 

Gordon Nichols posted:

I'm still thinking you'll be putting that new alternator in. 

Ryan,

I think, somewhere deep inside, you know it's the alternator. I don't know if you don't want to change it because it's going to be a bigger job than you thought or something, but you knew you needed it when you ordered your alternator from Amazon. Your charging system has exactly one part-- the alternator. You already tried the battery, and when the battery is charged, everything works normally. Whether it's the voltage regulator or not is irrelevant, since it's inside the alternator. The grounding strap could be bad, I guess-- but then you'd still have issues with a new battery.

You didn't.

A good alternator puts out 14.2v +/-. It should put out 14.2 v at idle, at 3000 RPM, with no load, or with every accessory known to man turned on. I'm assuming from the pictures you don't have any 5000 watt stereo or aircraft landing lights, so If the voltage drops below 13.6v while the car is running, it's bad.

Stan Galat, '05 IM, 2276, Nowhere, USA posted:

aircraft landing lights

You underestimate me.

I just don't understand how you mere mortals drive without aircraft landing lights.

Seriously though, I'm not against installing the alternator. I just want to make sure I've correctly diagnosed the problem before I complicate matters.

Oh, young Ryan... we middle aged guys can't see anything without a spotlight. I've got the big-boy H4s, and I'm probably going to LED sometime soon.

Your alternator still ought to be able to keep up, unless they draw about 500w.

Mr. Ohm has a law: volts x amps= watts. A stock Bosch alternator puts out 55a, or at least 660w (probably closer to 780w). Your (impressive) lights don't draw that much.

BTW: Really cool shot. Actually, almost every photo you've put up so far has been very cool.

Stan you really rattled my old cage, I had totally forgotten Ohm's Law ......

Eastern Religions specialize in Ohmmmmsssss law. 

That pict is awesome for sure.