Alternator, Ground or Starter.

Eric Cartman

Ok so my Range Rover is having an issue. It's starting intermittently , its a complete roll of the dice when you hit the start button as to whether the solenoid just clicks or it actually starts.

This started Tuesday so :
I replaced the battery as the old battery was from 2013 , Charged the battery overnight with my ctek charger and the battery indicator is showing green, battery putting out 12.6-12.8 volts when the car is off.

I can run the car with everything electric turned on and the diagnostics show the alternator holding it, no lights dimming, no errors.

when the car starts, the starter makes a weird metal clanging noise like its not retracting properly or something.

once it actually starts there are no issues whatsoever, no fault codes, no issues running, no weird noises.

when you hit the start button its a complete roll of the dice , however if you hook up another car or booster pack (even with a poor connection to the jump leads, barely tipped off it) it starts no bother instantly.

Halfords tested the new battery and said its perfect, its a Yuasa AGM battery, the reset was done so the car can give it the correct charging level.

The mechanic thinks its the alternator, basing that on that it only puts out 13.7v not increasing with revs, but the battery is full and thats the charging level for an AGM battery thats full so I don't really believe that, when the battery was put in and it wasn't as charged , it was putting out 14.4 volts which is the full load charging.

I think its either the starter itself or a bad connection, how is the easiest way to test the cables to check for a bad earth / bad positive ?

dooroy

If the solenoid clicks but no start it would point to a problem with the starter -brushes sticking /worn etc .
And if the starter is making unusual noises I would certainly remove it for a check over - and maybe prevent further damage (ring gear etc ).
Is it manual or auto ?
There aren't many cables in the starter 'circuit'- best way is remove connections and make sure there is no corrosion etc. Then get cable ends , contact points etc nice and clean and shiny , give them a smear of petroleum jelly and refit.
Connections can appear tight and problem free but when you remove them you find hidden corrosion etc .

mullingar

The easiest way to check for a bad earth under load is to check the voltage between the alternator body and the battery negative and then the chassis with engine running. It should not be more than 0.1V.

martyc5674

mullingar wrote: »

The easiest way to check for a bad earth under load is to check the voltage between the alternator body and the battery negative and then the chassis with engine running. It should not be more than 0.1V.

This is the way to do it but in reality you need to do it whilst staring the car and putting a real heavy load on the battery.
Put one lead of your meter on the battery -ive terminal and the other on the starter motor -ive/body.
Crank the engine and see what the voltage rises to across the earth, around a volt is ok.. much more and your losing too much.
Do the same with the +ive.
Marty

rex-x

It will be your starter