Ammeter is a device used to measure current in a circuit. Its connected in series with your battery. It does not do any work in the circuit its just another device.
The ammeter in the Jeep is a Zero center ammeter you must have seen this elsewhere too with the needle in between with the reading symmetric on both sides of it. Call it the flow direction meter lol...
Once you turn on the key the ammeter will deflect to one side showing the battery charge is being taken up. Once you crank the engine it goes the opposite side showing you that current is flowing to the battery getting it charged. Thats why it has symmetrical dial with same numbers on both sides.
Sankar said the same thing as what i mentioned. Got it?
Last edited by Spitfire : 27th June 2008 at 20:56.
Ammeter is nothing but a amp meter So when the current flows through it, it will move in the direction of flow. + indicates battery is getting charged and - means discharge from battery.
When you switch on the ignition, meter will show slight discharge (towards -) then when you crank, it will further move to (-). Once the engine is running, alternator takes over and charging will happen (meter moves to +).
Now if battery is slightly discharged (as in overnight stop), meter will raise a lil towards + and then settle down to around first mark of the meter after couple of Kms. This usually happens with battery voltage climbing and alternator regulator regulating the voltage and the charging.
On the other hand if battery is really weak, one cell dead, etc etc the charging will show at a higher rate towards + and will not settle down.
So a raised amp meter reading is a sign of bad battery, faulty regulator/alternator. On the contrary if the meter moves to (-) even when engine is running, it means that alternator/charging circuit is not working and the battery is providing the current required for the vehicle.
Since your jeep is a diesel, not much of current is required during normal running. Apart from the lighting and all. Which reminds me, even when the charging is working fine when lights kicks in there will be a small dip in amp readings, since alternator is feeding the lights along with the job of charging battery.
Get a bocsh battery they have a wide range and it is really good, I alway used Exide in my Jeep [ they last for around three year], mine was peugoet engined.so heating of the engine everytime..but My friends jeep uses bocsh and it lasted him more than 4 years on the same engined Jeep, so for a Di engine it will be great. and also they have higher amp rating for a little more price, great for cranking... and can run heavy loads [fog lamps,etc].
Ammeter - I think it goes to the right even if the battery is not charging.
Speaking of batteries, please remember that these vehicles can be push started - anybody with acces to the vehicle can press the clutch and push start it. It does not require battery to run (Unlike petrols). ANd once the engine is running, even during the night, the alternator will give out enough current to light up the head lamps.
Jaggu's post really clear it up. BTW, I did know what an Ammeter does, as I had studied it in college, but didn't know what it meant on a Jeep.
Originally Posted by madbullram
Samurai: I have picked Amaron Hi-Way 80 Amp Battery for my CJ3B. Taking into consideration that my headlights are 100W and my Fogs are 130W I went with 80 Amp.
How much did it cost?
Originally Posted by dinar
Get a bocsh battery they have a wide range and it is really good, I alway used Exide in my Jeep [ they last for around three year], mine was peugoet engined.so heating of the engine everytime..but My friends jeep uses bocsh and it lasted him more than 4 years on the same engined Jeep, so for a Di engine it will be great.
I too have Peugeot engine. I too want enough juice in the battery to add the fogs someday. So, 80A should be enough?
In future I might want to add couple extra lights to the front. Need enough juice for that.
You need a battery that is big enough to crank the motor hard enough to start it in cold weather. Your alternator is what should be running all auxillary electrical equipment including lights. It needs to be big enough to do this.
Ok, is the CJ340 alternator good enough for extra lights, I hope so.
Meanwhile, the battery appears to be fixed pretty well. I hadn't touched the Jeep in 3 days since I couldn't drive it out without the soft-top, it is raining all the time. Just now I cranked it, and in 5-6 seconds it started, in the very first crank. Before I had to try it 3-4 times if I am starting first time in the day. Also, the last 3 days were extremely wet and moisture in the air was probably 80-100% all the time.
Now, how does one start the Jeep without a battery? I recall an old technique from the 80s where we pushed the car in neutral and then slip in the gear. Does that work here?
I was told by my friend who owned and old MM540 that one could just push start the jeep even without the ignition(?) keys. Never in a petrol engine, since you need that spark.
Samurai, why don't you try it out yourself after taking it to an incline? (FYI, I have, in the past, pushed and started our premier padmini - all by myself, on a flat road, early in the morning). In your jeep, it will be tougher - since it is heavier - however the lack of doors mean that you can jump in easily once it attains momentum. Try it out early in the morning, when the roads are empty.
If you prove that those keys are not needed to start, then it's time for you to think of anti-theft mechanisms