mechanical vacuum pump to replace dynamo/combo unit

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ee Mechanical Help
All the problems and possible solutions detailed below are provided by the experienced automotive mechanical engineers who carry out our vehicle inspections. The problems covered can be common to most vehicles but the list is by no means exhaustive. If your particular mechanical problem is not answered below ask our engineers for mechanical assistance here.

How to test a car alternator.

Car Alternator.
The car alternator is used to charge the car battery when the engine is running and is a perishable item on a car which can fail after many miles of motoring. When the alternator fails usually the battery light will come on on the display to indicate the battery is no longer charging.

Alternator on petrol cars.
On a petrol car the alternator is more crucial than on a diesel car as the battery provides the power for the spark therefore if a battery is not charging the battery will eventually flatten and no spark will be generated causing engine failure.

Alternator on diesel Cars.
Although the diesel car needs a battery for electrical items such as lights, indicators, radio, fans, rear demist, windscreen wipers...etc, once the engine is running it does not need electrical power to keep running. In the event of an alternator failure you would not be stranded by a engine shut down but safety would be compromised by loss of signalling and lights.

Testing your alternator.
Testing your alternator is a quick and simple. You don't need to remove the alternator to carry out a test and it doesn't require expensive tools.

Click to view large image
What you will need is a volt meter or multi meter. They are very simple to use, and can be purchased in many retailers for as little as £5.




Alternator Test.
Make sure all the electrical items mentioned above are turned off and then have someone rev the car's engine to a fast idle (say 2000-2500 rpm).

Set the Voltmeter to DC and place the red lead of the voltmeter on the positive terminal and black lead on the negative terminal of the battery.

At a fast idle, the voltage should read approximately 14 volts (13.5 to 14.4). Although your battery will be likely 12 volt the alternator has to generate a larger voltage to overcome the internal resistance of the battery. The current needed to recharge the battery would not flow if the alternator output was the same as that of the battery.

If the reading on the volt meter is less than 12 volts then you may have a failed alternator.

One last alternator check.
Turn on all the electrical items. Now have someone rev up the engine again and check the voltmeter. It should still be reading around 14 volts. If it reads lower than 13 volts the chances are that the alternator is faulty and will need to be replaced befor
http://wheretobuycarsfrom.com/how_to_test_car_alternator.asp
 
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How Do I Check My Car Battery?
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How Do I Repair My Car? / How Do I Check a Car Battery?
How Do I Check My Car Battery?

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Checking Battery and Charging System:

Wear protective eye wear and clothing and remove all jewelry when checking your battery and charging system. Jewelry is a good conductor of electricity and is not recommended. Most batteries wear out every 3 to 5 years and need to be replaced. Always replace your battery with an equal replacement battery to assure proper operation. Automotive batteries have a +positive terminal (red), - negative terminal (black). The battery in this illustration has a protective cover over the positive terminal to prevent short circuit in case of an accident. Electricity is stored in the battery and then supplied to the vehicle when the engine is not running. While the engine is running the vehicles alternator charges the battery for future use. (Note: never disconnect the battery while the engine is running. If the battery cable is disconnected from the battery a spark can be generated which can cause the battery to explode or a major electrical malfunction to occur.)

Step 1 - Checking Battery

Battery

To check a battery surface voltage, remove the positive terminal protective cover. Connect the +positive side meter lead (red) to the positive side battery terminal. Connect the - negative (black) side meter lead to the negative battery terminal. With the vehicle not running and the car sitting over night the battery voltage should be between 12.5 and 12.8 volts.

Step 2 - Identify Alternator

Alternator

The alternator is rotated by a drive belt driven by the vehicles engine while it is running. Electrical voltage and amperage are generated to recharge the battery and supply voltage to the electrical system of the car. The alternator is held in place with mounting bolts. There is a main electrical wire on the rear of the alternator that supplies voltage to a main voltage junction box. If your alternator is not charging properly, your battery will slowly drain down from operating all the electrical systems in your car and stop the car from running.

Step 3 - Checking Alternator Output

Checking Battery

Connect the voltage meter lead the same way you would in a battery static voltage check, Start engine (do not drive) at engine idle the voltage should be between 13.6 to 14.3 volts. If not the alternator may need replacing.

Step 4 - Checking Alternator Amperage Output

Testing the amperage output of the alternator is good for measuring the amount (not the level) of voltage the alternator can produce. This test can be tricky because if the alternator is weak it can still show it as producing amperage. Which is good, but if the voltage is low, it will still allow the battery to go dead. To check the amperage output of an alternator an amp meter is needed. Once the meter is connected start the engine. Next turn on all electrical accessories and raise the engine idle to about 1200 RPM. The alternator should output the max amperage it was designed to produce. Example: a 90 amp alternator should output about 88 amps. Note: An alternator cannot sustain maximum output for long periods of time. If the alternator is forced to operate at maximum output it will overheat and fail. An alternator is designed to operate at max amperage output only for a reasonable amount of time.

Common Problems:

1. Alternator stops producing electrical power and the car stops because the battery dies.

2. Battery fails do to age or defect.

3. Battery cables
become loose causing the electrical system to fail.
 
So how about using a hydro boost system like one fron an Astro van? Will it work?
 
BigBrownDog,

When you say things such as:



Guys with my background start to get concerned that damage will occur, or that you are not sure what, precisely, you are referring to. Which is what prompted my warning about measuring current draw. Measuring current is done in series on a DMM. Voltage measurements are made in parallel. Maybe you were thinking voltage drop when a considerable load is applied, I don't know, but your words were indicating a current measurement. If you attempt to measure the current draw under full load, you WILL most likely pop the current protection fuse on your meter.

None of this is meant as a personal attack. You probably already know what I am trying to tell you, but from this post, I felt a precautionary note was in order. What I really don't want is someone with zero electrical knowledge attempt to make current measurements in a high current environment. Maybe if they read my warning, they will think long enough about what they are doing to ask someone in the know!

I wouldn't be so retentive about this, but I know there are a lot of guys that, through this site, are encouraged to turn a wrench or two and fix a circuit here or there.

And now back to your regularly scheduled program!

Well mate I would suggest you post up the best way to do it with the specific terminology you obviously require instead of highlighting [inappropriate ] words that most of us would understand what was meant. I posted the test hoping that it would help someone as I have found it to be quite effective.
I don't believe you need to be a rocket scientist to do the test on the battery/ alternator.
 
So how about using a hydro boost system like one fron an Astro van? Will it work?

I was soo tempted to do it last december .. but it drive me to another question ..

would you lie to put your brakes along with your PS pump .. ? it's like put all the eggs in the same baset .. who knows ..

I just upgrade my PS pump and the complete system in order to run my steering assist ram .. but still not sure if it's the way to go ..

If I tae will be free to run what ever alt I want .. that would be nice !
 
Well mate I would suggest you post up the best way to do it with the specific terminology you obviously require instead of highlighting [inappropriate ] words that most of us would understand what was meant. I posted the test hoping that it would help someone as I have found it to be quite effective.
I don't believe you need to be a rocket scientist to do the test on the battery/ alternator.

Using a voltmeter to test is kind of a go/no-go thing. You can measure that the alternator is not keeping up with the load but can't measure how much current it is producing. A dc clamp meter is a relatively newly available tool ( old ones were very expensive) that can tell you how many amps are flowing in a wire or group of wires. It is very handy for figuring out your total load with all accessories, alternator output, how much is flowing into or out of the battery etc. Also very handy for tracking down parasitic draws.
 
I was soo tempted to do it last december .. but it drive me to another question ..

would you lie to put your brakes along with your PS pump .. ? it's like put all the eggs in the same baset .. who knows ..

I just upgrade my PS pump and the complete system in order to run my steering assist ram .. but still not sure if it's the way to go ..

If I tae will be free to run what ever alt I want .. that would be nice !

It has been done on Cruisers before. When you lose a power steering belt you'll wish you weighed 400 lbs to stop and turn the rig.
 
Using a voltmeter to test is kind of a go/no-go thing. You can measure that the alternator is not keeping up with the load but can't measure how much current it is producing. A dc clamp meter is a relatively newly available tool ( old ones were very expensive) that can tell you how many amps are flowing in a wire or group of wires. It is very handy for figuring out your total load with all accessories, alternator output, how much is flowing into or out of the battery etc. Also very handy for tracking down parasitic draws.

Cheers Bruce, Thanks, my son owns one as he is electrician+aircon/fridge qualified.[240Volts here] I only own a multimeter and I am guessing most of the blokes also may only own a multimeter or could buy one very cheap. My thinking is quote,, "You can measure that the alternator is not keeping up with the load but can't measure how much current it is producing."
If this shows isn't this a good sign that the alternator may need repairs. Surely this is better than driving it until it fails totally? This alternator pic previously let my battery flatten but was not showing a discharge rate on the gauge also no alternator light was on including other warning lights. However I was able to read it was faulty with the multimeter.As you can see in the picture the brushes are still in a good state from the repair I carried out a couple of years ago. Regards
 
It has been done on Cruisers before. When you lose a power steering belt you'll wish you weighed 400 lbs to stop and turn the rig.

options options !!!!

fact .. I'm still attached to my vacc alt system ..
 

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