Alternator Output

jacckk · Aug 12, 2014

My battery has been gradually getting flatter over the last couple of days (I could tell from the dash getting dimmer when cranking). Today it was flat enough for it not to start even after a relatively long drive yesterday. I've got the latest RF receiver and haven't had any issues with the battery going flat until recently.

I've recharged it and between the two battery terminals at 2000rpm I'm getting 13.6V. At idle it's 13V. Measuring between the positive connection on the alternator and the rocker cover I'm getting 14.1V.

I remember someone saying it should be 14.2V at 2000rpm. Is this something wrong with the alternator or something wrong with the wiring that I should be looking at?

DavidMcMahon · Aug 12, 2014

I have this in the workshop

Hope this helps, of course Ranger Rover specific might well be different, so wait for experienced heads to pipe up.

Datatek · Aug 12, 2014

jacckk said:
My battery has been gradually getting flatter over the last couple of days (I could tell from the dash getting dimmer when cranking). Today it was flat enough for it not to start even after a relatively long drive yesterday. I've got the latest RF receiver and haven't had any issues with the battery going flat until recently.

I've recharged it and between the two battery terminals at 2000rpm I'm getting 13.6V. At idle it's 13V. Measuring between the positive connection on the alternator and the rocker cover I'm getting 14.1V.

I remember someone saying it should be 14.2V at 2000rpm. Is this something wrong with the alternator or something wrong with the wiring that I should be looking at?

14.1 volts is OK 14.2 is better, but you have a problem between the battery and alternator, there should not be a volt drop of 0.5 to 1.1 volts from the alternator to the battery. There have been problems reported with the cable corroded between the alternator and battery and you als need to check the earth from the engine and chassis. You can test by using a jump lead from the alternator case to battery negative and see if the volt drop reduces, you can do the same from the alternator output to the battery positive.

jacckk · Aug 13, 2014

Alternator positive to battery positive gave 1.8V
Block to negative was 0.8V

So both aren't ideal.

Datatek · Aug 13, 2014

jacckk said:
Alternator positive to battery positive gave 1.8V
Block to negative was 0.8V

So both aren't ideal.

Add new 4mm cables from the alternator case to battery negative and alternator output to battery positive.

wammers · Aug 13, 2014

Clean the cables on the starter solenoid.

Alternator Output

jacckk

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DavidMcMahon

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Datatek

Well-Known Member

jacckk

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Datatek

Well-Known Member

wammers

No longer with us, RIP

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