Vauxhall Workshop Service and Repair Manuals

Battery/Starter (Voltage Measurement)  

Two checking methods can be used to evaluate the battery and starter. The voltage measurements described here should be used for vehicles where it is not possible to adapt the current probe to the battery connection leads because of the cable routing or the number of cables.  

Measurement:	Progression of the battery voltage during the start procedure.
Check Objective:	Evaluation of the state of charge of the battery and the current supply to the battery as well as the operation of the starter.

Preparation  

Switch off the engine, switch off ignition, switch off all electrical loads.  

Connections  

INPUT A	COM/TRIGGER
Connect red measurement lead to the battery. Ensure correct polarity!

Procedure  

Start engine.  

Reference Curve

If the measured signal progression still does not correspond to the reference curve after the test is repeated, the fault must be isolated using the fault diagram below and if necessary continue measuring.  

Fault Diagram 1   Symptoms:   Minimum < 7 Volt   Signal start < 12 Volt   Signal end < 14 Volt

If the voltage levels are too low for the start and end signals, this clearly indicates that the battery is insufficiently charged. This can result in the high voltage dip on starting (minimum value).  

Possible Causes	Countermeasures
Poor contact	Check the supply leads and connections on the battery and starter.
Discharge battery	Charge battery and recheck. If OK, check alternator.
Battery faulty	Check battery and replace if necessary.

 

Fault Diagram 2   Symptoms:   Minimum value < 7 Volt   Signal start < 12 Volt   Signal end constant < 14 Volt

Possible Causes	Countermeasures
Poor contact	Check supply leads and connections on battery and starter.
Faulty starter	Check starter and repair starter if necessary.

 

Note   Voltage dips in the last third of the measurement curve can be traced to the activation of the air pump on vehicles with secondary air injection (X-engines) and a cold engine.   This does not represent a fault!