|
gwagen460swb
Extreme Veteran
Date registered: Apr 2006
Location: Oklahoma City, OK
Vehicle(s): 280GE SWB, Toyota Highlander, BMW530i, RR HSE
Posts: 513
| Mechanic Pulling My Leg?
Yesterday I finally decided to change out my battery. I had a 48-month Interstate battery that was installed in May 2002. So my battery was running on 51 months. Pretty good considering a G uses a lot of juice. My previous SUVs were lucky to make it to 42 months. I was driving about two miles from my house after a gas fill-up. That was when I noticed my stereo went out. Then my close door/ignition off beeps prematurely came on. My G was starting to konk out--or I should say my battery was going to go. I had this same thing happen to me on a Mitsu Montero I use to own. Anyways, bought a battery and needed a new battery cable. I went to nearby Indianhead Mastertechs Rolls Royce/Classic MB/Jaguar (not too far from my trusted mechanics at Sherwood Imports) for my battery cable. This place opens until 10pm 7 days a week. They were kind to allow me to use one of their bays and tools to do my stuff. Installation was a snap. The G cranked up with no issues; better than before. To make a long story short, the mechanic offered to test my new battery using his volt meter. The volt meter was registering 12.2V. He said the meter should register 14.4V. Because of my 12.2V, he said I needed a new alternator. I had my G serviced almost two months ago and the alternator was fine. My G was registering 11.98V when I first got it and I had no issues whatsoever. Don't worry; I did not buy a new alternator. So was the mechanis trying to pull a fast one on me? |
|
| |
|
roughneck
Expert
Date registered: Apr 2006
Location: UK, Germany & USA
Vehicle(s): 270 cdi.300 GD 300 GE.lwb 300 GE.swb. Disco 2
Posts: 4398
| RE: Mechanic Pulling My Leg?
IMHO. He was dead right, a 12v system needs min 14v to charge it. |
|
| |
|
Braingears
Expert
Date registered: Apr 2006
Location: St Petersburg, FL
Vehicle(s): G320 & ML320
Posts: 1450
| Re: Mechanic Pulling My Leg?
That might also mean that your old battery was still fine.
I would check your existing alternator. A few months ago, I had to replace the brushes on my alternator. They simply wore down. The Bosch part cost me $40, and I was up-and-running again.
|
|
| |
|
gwagen460swb
Extreme Veteran
Date registered: Apr 2006
Location: Oklahoma City, OK
Vehicle(s): 280GE SWB, Toyota Highlander, BMW530i, RR HSE
Posts: 513
| Re: Mechanic Pulling My Leg?
Thanks Chuck for the advice. I'll have to look into that. Another thing I forgot to mention was when I charged my old battery, it did not take long for the G to start up. Once I turned off the ignition, it would not start again nor would anything electrical come on. As I said before, I am fine now. |
|
| |
|
Braingears
Expert
Date registered: Apr 2006
Location: St Petersburg, FL
Vehicle(s): G320 & ML320
Posts: 1450
| Re: Mechanic Pulling My Leg?
Once a battery goes below 40%... the battery never truly regains its power again. By the sounds of it, you got a full life from this battery... |
|
| |
|
roughneck
Expert
Date registered: Apr 2006
Location: UK, Germany & USA
Vehicle(s): 270 cdi.300 GD 300 GE.lwb 300 GE.swb. Disco 2
Posts: 4398
| Re: Mechanic Pulling My Leg?
Braingears - 7/10/2006 3:40 PM
That might also mean that your old battery was still fine.
I would check your existing alternator. A few months ago, I had to replace the brushes on my alternator. They simply wore down. The Bosch part cost me $40, and I was up-and-running again.
I may be wrong, but I don't beleave there are brushes on an alternator. |
|
| |
|
Braingears
Expert
Date registered: Apr 2006
Location: St Petersburg, FL
Vehicle(s): G320 & ML320
Posts: 1450
| Re: Mechanic Pulling My Leg?
roughneck - 7/10/2006 4:43 PM Braingears - 7/10/2006 3:40 PM That might also mean that your old battery was still fine. I would check your existing alternator. A few months ago, I had to replace the brushes on my alternator. They simply wore down. The Bosch part cost me $40, and I was up-and-running again. I may be wrong, but I don't beleave there are brushes on an alternator. Yup... They have brushes... and I have replaced them. If you actually know that it is brushes in the first place, it only takes 10 minutes to replace them.
 (Alternator.gif)
Attachments
----------------
 Alternator.gif (29KB - 12 downloads)
|
|
| |
|
gwagen460swb
Extreme Veteran
Date registered: Apr 2006
Location: Oklahoma City, OK
Vehicle(s): 280GE SWB, Toyota Highlander, BMW530i, RR HSE
Posts: 513
| Re: Mechanic Pulling My Leg?
I checked my records. My alternator was replaced in June 2003. In all the vehicles I have owned, the earliest I have had to change an alternator was seven years (2002) on my 1995 Mitsu Montero.
My 2000 LR Disco II is coming up on seven years (manufactured in 1999 and sold in North America in 1999 as a 2000 model). I did have to change the battery in 2003. Cross my fingers; no issues yet with alternator, starter, or battery.
I have no records on my G prior to 1999. That would be fantastic if an alternator lasted 21 years on a 1982 G! At worst, I am guessing there may have been an alternator replacement maybe 10 years ago. If that is the case, my current alternator installed in 2003 should still have life. |
|
| |
|
Inkblotz
Expert
Date registered: Apr 2006
Location: Georgia
Vehicle(s): 90 300GD "Thundering Turtle II", w/ 603A turbo
Posts: 3186
| Re: Mechanic Pulling My Leg?
This may be an obvious question but: Had you checked the water level on your old battery? Many people never look at their battery because they are told they are maintenance free. However there are still caps that pop off to check the water level on these batteries as well. A low water level will exibit the same ills your G experienced.
I have had Interstate batteries last the life of many of my old Mercedes in the past. They are my first choice in batteries.
Just a thought
Mark
Edited by Inkblotz 7/11/2006 7:59 AM
|
|
| |
|
Ernest T Bass
Date registered: Dec 1899
Location:
Vehicle(s):
| Re: Mechanic Pulling My Leg?
Put simply the charge from the alternator must be greater than the battery it is attempting to charge. A 12v battery will need about 13-14v to charge. Any less will fail to charge properly and more will fry it.
The simple check is to first measure the volts across the battery with the engine off – a fully charged 12v battery will read over 12 13ish (not absolute but more that 12.5)
Start the engine and measure the voltage at about 2000 + rpm it should be 13-14ish, if its not then suspect the alternator.
The cheap solution is as has been stated is to change the brushes (107 in Chucks picture) – the regulator could also be suspect (104 in Chucks picture) My EPC does not say if the brushes come with the replacement regulator. It is, however, a simple job and removing the brushes will let you see how bad a state they are in.
|
|
| |
|
dai
Expert
Date registered: Apr 2006
Location: Oregon USA
Vehicle(s): 300GD 300TD BMW R100RS Landini 80F
Posts: 2110
| Re: Mechanic Pulling My Leg?
The brushes and regulator are together in '80's era Diesel G's. 80% of the time this is the reason for alternator failure. Buy a good part (Bosch) with the round regulator and not one of the long rectangular cheap crummy will fail immediatly units. It is held in the back of the alternator with two screws and is a 10 minute job to change out with the alternator in the vehicle.
Clean and check the wiring where it plugs into the alternator and make sure the contact is solid.
Put the battery on a charger and get it to the point where is shows 12.5 + volts. Low voltage in a battery is very hard on an alternator and will lead to early failure. Alternators can fail anytime but usually don't. Test it at the battery. You should get 12.5 + with a healthy battery. Start the vehicle and test it again at a fast idle. It should read 13.5+ . If the voltage remains 12.5 or whatever your first reading was the system is not charging. Most likely brushes/volatage regulator. Any simple voltmeter that reads DC voltage will work. I prefer the digital readout ones and Radio Shack makes a slick small clamshell digital one that the wires and probe ends wind up in the lid. Cheap and excellent.
-Dai
Edited by dai 7/11/2006 10:59 AM
|
|
| |
|
roughneck
Expert
Date registered: Apr 2006
Location: UK, Germany & USA
Vehicle(s): 270 cdi.300 GD 300 GE.lwb 300 GE.swb. Disco 2
Posts: 4398
| Re: Mechanic Pulling My Leg?
Braingears - 7/10/2006 11:34 PM
roughneck - 7/10/2006 4:43 PM Braingears - 7/10/2006 3:40 PM That might also mean that your old battery was still fine. I would check your existing alternator. A few months ago, I had to replace the brushes on my alternator. They simply wore down. The Bosch part cost me $40, and I was up-and-running again. I may be wrong, but I don't beleave there are brushes on an alternator. Yup... They have brushes... and I have replaced them. If you actually know that it is brushes in the first place, it only takes 10 minutes to replace them.
Yup you are right, civilian vehicles have alternators with brushes, much of my experience is with military Gs and they have brushless alternators. |
|
| |
|
w.james
Veteran
Date registered: Jun 2006
Location: New Jersey
Vehicle(s): 84 280 GE 617A 5sp getrag
Posts: 239
| Re: Mechanic Pulling My Leg?
I was told that the brushes were good (and making contact) if the dash light for the battery comes on when the engine isn't running. Is this true? |
|
| |
|
gwagen460swb
Extreme Veteran
Date registered: Apr 2006
Location: Oklahoma City, OK
Vehicle(s): 280GE SWB, Toyota Highlander, BMW530i, RR HSE
Posts: 513
| Re: Mechanic Pulling My Leg?
Ready for the verdict? I just came back from my trusted mechanic at Sherwood Imports. It looks like Ernest wins the big platter of fish n' chips with his choice of pint. Alternator and brushes were still good. It was my regulator that went bad.
By the way, I did check my previous battery. Although hard to describe in words, it was pretty bad. I know when I need a new battery. |
|
| |
|
gwagen460swb
Extreme Veteran
Date registered: Apr 2006
Location: Oklahoma City, OK
Vehicle(s): 280GE SWB, Toyota Highlander, BMW530i, RR HSE
Posts: 513
| Re: Mechanic Pulling My Leg?
Okay, I should have been a little more specific or careful with my words. I meant to say my mechanic was pretty sure or thought the regulator was bad.
After replacing regulator, the voltmeter (when attached to my battery) still read 12V or below. What is part #86 in the diagram? |
|
| |
|
Ernest T Bass
Date registered: Dec 1899
Location:
Vehicle(s):
| Re: Mechanic Pulling My Leg?
gwagen460swb - 7/13/2006 8:57 AM
What is part #86 in the diagram?
It looks like the condenser |
|
| |
|
dai
Expert
Date registered: Apr 2006
Location: Oregon USA
Vehicle(s): 300GD 300TD BMW R100RS Landini 80F
Posts: 2110
| Re: Mechanic Pulling My Leg?
With the motor off the voltage you read off of the battery will be the battery voltage only, the regulator has no impact on that reading. Your charge is low on the battery if you only get 12 volts.
When you start the motor and take a reading what is it? It should change and be 13.5 / 14 or so volts. This indicates the alternator is charging. If it stays a 12 you still have an issue. Was the alternator tested off the motor for output? If it tested OK after the new regulator was installed then you may have an issue with one of the wires connecting to the alternator.
-Dai |
|
| |
|
gwagen460swb
Extreme Veteran
Date registered: Apr 2006
Location: Oklahoma City, OK
Vehicle(s): 280GE SWB, Toyota Highlander, BMW530i, RR HSE
Posts: 513
| Re: Mechanic Pulling My Leg?
When we started the engine (including reving it up a few times), we still had a 12V or below reading. The last I talked with my mechanic yesterday, he said wire(s) to alternator might be the other issue. I will know later. |
|
| |
|
Klaus Hoffmann
Date registered: Dec 1899
Location:
Vehicle(s):
| Re: Mechanic Pulling My Leg?
I had a similar problem on our old G. Removing the alternator bracket, sanding it and the mating surface and then reinstalling it fixed it. The battery and alternator were ok, there was a weak ground due to corrosion.
Klaus |
|
| |
|
roughneck
Expert
Date registered: Apr 2006
Location: UK, Germany & USA
Vehicle(s): 270 cdi.300 GD 300 GE.lwb 300 GE.swb. Disco 2
Posts: 4398
| Re: Mechanic Pulling My Leg?
gwagen460swb - 7/13/2006 7:18 PM
When we started the engine (including reving it up a few times), we still had a 12V or below reading. The last I talked with my mechanic yesterday, he said wire(s) to alternator might be the other issue. I will know later.
Underneath the air filter attached to the inner wing is a junction box for the wires from/to the alternator / ignition / starter. check here for corosion and or broken wires |
|
| |
