If the poor cranking is due to a loose/corroded connexion in the TOTAL high-current system, connecting another battery across the existing battery posts will make no difference, even if it's big enough to start a ship. (LOL, ships use donkey engines to start them).
In your case, I would carefully loosen and examine every heavy-current connection, especially including the ground-strap between engine and chassis. Don't forget, the -ve cicuit from the battery, which will include the chassis, is just as important as the +ve. If you find corrosion, out with the files and emery cloth. It's ok to grease them after treatment. Do not overtighten any brass nuts. If you've been trying to start for a time, but are cranking slowly, the poor connexion will get hot. How's that for a giveaway?

Leedsman.

 

Did you check the switch for the door mirrors?

 

Hi Richard,


Just to let you know that a new starter motor has been fitted, also another brand new Bosch Battery type advised by Chrysler. guess what..... still wont go at all. All earths etc also checked. Car has been taken to specialist electrical engineers and they cant find a fault either.


Think I will head down to the river........


Thanks again


Bill

 

Hi alan,


Yes switch has been checked and all is ok.


New battery, new starter motor been fitted, earths etc all checked and still wont start.


The pain continues......


Thanks for your help


Bill

 

Playing "parts darts" is not the most economical way of fixing a fault.

Did you find out what the cranking RPM is? I would like to hear a quantitative value rather that a feeling that it's cranking slowly. If the RPM is sufficient for the ECU to fire the injectors then you could be heading up the wrong path.

Did you get the voltage readings? Again, earths and connections can be visually inspected but you need the voltage readings when the circuit is under load to confirm. As Leedsmans says, it's the total path that needs to be checked.

Regards
Richard

 

Are you abs. sure ALL the ground connexions have been checked? Apply a voltmeter across the starter motor and check the voltage during cranking. It should be more or equal to 9volt. (For a 12volt nominal battery). Apply the -ve lead of the voltmeter to the CASE of the motor to ensure you are genuinely checking the voltage across the motor. not across a dodgy connexion. Someone in the past might have replaced some of the starter wiring with cable that's too thin for the job. Again, putting the voltmeter across the ends of any cable will revealed the volts-drop across it during cranking. You can check the volts-drop across the solenoid switch the same way.

Basically, this circuit is so simple it shouldn't need an Einstein to figure it, but in practice it's not easy like say, house-wiring where you can see everything.

Leedsman.

p.s. I run my 2.8 CRD engine with TWO starter batteries which I keep on float-charge of 13.8volt. 24/7. It cranks like fury every time.

 

If it's got side steps fitted then it'll never sink. But you can sell them to me before you get to the river bank.