nick25crd
Member
hi,my alternator gives 13.5V.Could it be a problem to my battery?
alternator problem
- Thread starter nick25crd
- Start date
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Billwill
Full Access Member
That is exactly what it is supposed to do with the engine running!
That is how charging works...alternator voltage being greater than battery voltage hence current flows into battery and charges it.
You can expect it to go up to about 14.5 volts while revving the motor.
The ECM controls the voltage output from the alternator...I had some wiring problems on MY 2.5 CRD which caused the voltage to rise to about 17 volts before the ECM kicked out and shut the motor down...my so called sealed battery became unsealed and threw out a lot of acid water and bulged badly so I had to buy a new battery.
A voltage of 13.5 is perfect!:icon_lol:
nick25crd
Member
is it common to have wiring (alternator-battery)probems?
Billwill
Full Access Member
It is common to have battery problems and the clutch on the alternator pulley does give problems so the alternator does not run up to speed.
I had some wiring problems in the charging area but I believe the faulty wiring was caused from an accident when a tree jumped in front of the Jeep while my SO was driving.....the main wiring harness runs around the front of the jeep below the radiator and I believe several wires got damaged there.
The best way to monitor charging problems is to temporarily fit a voltmeter to plug into your cigar lighter socket so you can monitor the voltage while you are driving....I had some weird problems such as when I activated the front wipers..even for a single stroke, or when I turned on the air con, then the charging voltage would climb rapidly to about 17 volts at which time the ECM shut down the whole vehicle.
Hopefully you do not have such a drastic problem but you can at least see if the alternator s charging steadily.
What exactly is the problem that you are having?
nick25crd
Member
I bought my battery from one of my friends one year ago.In January,when it was still winter in Greece i first have problems with starting my 2.5 crd.He tested the battery(and recharged it) for 2-3 times until May.He always said to me that the battery is O.K. and i have no reason to have any doubt.The point is that i have to face this problem and finally i
went to the stealership to have it checked as good as possible.The conclusion was that it could be the alternator or the wiring.The indication on the battery was 13.5V with the engine on.Also they tried my battery in another cherokee/liberty crd and the indication was 14.3V
so they said that the battery reacts O.K.
After all these i left the alternator at a man he is expert on remanufactoring.After he opened
it and tested it at all he only found that the decoupler pulley wasn't in good situation (165.000kms,changed once) and removed it because everything else was all right.
Now the indication is again 13.5 to 13.7V and that is why i am thinking about the wiring.
went to the stealership to have it checked as good as possible.The conclusion was that it could be the alternator or the wiring.The indication on the battery was 13.5V with the engine on.Also they tried my battery in another cherokee/liberty crd and the indication was 14.3V
so they said that the battery reacts O.K.
After all these i left the alternator at a man he is expert on remanufactoring.After he opened
it and tested it at all he only found that the decoupler pulley wasn't in good situation (165.000kms,changed once) and removed it because everything else was all right.
Now the indication is again 13.5 to 13.7V and that is why i am thinking about the wiring.
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Billwill
Full Access Member
What battery are you using? Does it have a high enough Cold Cranking Amperage?
The CRD needs a large battery to turn it over.... about 750 CCA I believe.
Check your battery earth strap is making good contact to the frame and your battery clamps are clean and tight.
The reason your charge voltage is only at 13.5 volts is that the ECM is sensing that the battery is up to full charge but...can it deliver the required amperage at starting time?
The CRD needs a large battery to turn it over.... about 750 CCA I believe.
Check your battery earth strap is making good contact to the frame and your battery clamps are clean and tight.
The reason your charge voltage is only at 13.5 volts is that the ECM is sensing that the battery is up to full charge but...can it deliver the required amperage at starting time?
warp2diesel
Full Access Member
Have an electrical shop check the alternator brushes. If the brushes are worn badly, they will not send enough current to the rotor to get the voltage out of the stator, even if the voltage regulator in the ECM is sending out the current. Also check the wire on the back of the alternator that sends the current to the brushes, if you drive too close to the coast where there is salt water, the connection can corrode. If you can get Wurth Contac-oel (?sp) electrical cleaner, it would be a good idea to clean up all the plugs going between the alternator, ECM, and the large fuse box next to the battery. Then get some die-Electric past like what they use on trailer plugs and put the past on like a politician spending tax money, you want excess to ooze out to keep out water and any salt water mist that may be in your area. If you have any Agriculture in your area, the stuff like insecticides and fertilizers the farmers use can also corrode your electrical connections.
The next thing to have your alternator shop check are the diodes or rectifier, if the brushes check out. Here in the US, most have lost the skill to repair alternators except for the ones used on the big rigs and large construction or farm equipment.
Do not run with out the decoupler pulley, if you do you will trash out your tensioner and trash out the belt. If the CRD engines had larger flywheels and larger harmonic balancers, we may get away with it, but most of us don't have the money and machine shops with lots of machine tools to make and balance flywheels. :happy175:
nick25crd
Member
Well,well,...warp2diesel thank you very much.
