Fitting Guide for Isolator DBE1T (large) with Jump Start Facility

Procedure

Find a suitable position near either battery. Mark holes for the isolator mounting bolts (not all bolts need to be used - do not twist or bend the isolator just to get the 3 bolts fitted). Drill holes and mount. Be careful not to over-tighten the mounting bolts.

Run 6mm wire to the main and auxiliary battery positive terminals, noting which terminal is which on the isolator. Run a 3mm wire from the earth terminal to the body making sure to get a good earth connection.

Run a 3mm wire from the Jump terminal to a single pole single throw switch, (dash mounted) which goes to earth when operated. It is best to use a momentary action switch to prevent bypassing the isolation system for extended periods. This unit is not suitable to start 6 cylinder or V8 engines.

If an electric winch or other high current draw accessory is fitted, run a 3mm wire from the "sens" (sensor) terminal to the accessory "live" when the accessory is operating. If no accessory is fitted to the vehicle then leave the sensor terminal vacant.

Intelligent Isolator Test Procedure

Check voltage of main and auxiliary batteries, both should be around 12.5 - 13 volts. The indicator light is 'red' indicating disconnect. Start engine and increase engine speed well above idle. Voltage on the main battery should increase to around 14volts. Once the main battery exceeds approximately 13.6volts the isolator will connect the auxiliary battery into the charge circuit. This can be seen by the voltage on the auxiliary battery rising to about the same voltage as the main battery. The indicator light turns 'green'. Note if the auxiliary battery is flat the isolator may alternately connect and disconnect it depending on the ability of the alternator to supply enough current to maintain the voltage of both batteries above approximately 12.8volts. The red/green light will off/on as the isolator disconnects/connects.

When the light is green, turn the engine off and turn on the headlights. Check the voltage on the main battery. Once this drops below approximately 12.8 volts the isolator will disconnect the auxiliary battery, this can be seen by the voltage on the auxiliary battery being higher than the main battery. The indicator light turns from green to red.

Alternatively, with the ignition off, put a load on the auxiliary battery. Once its terminal voltage drops below approximately 12.8 volts the isolator will disconnect it from the main battery. This can be seen by the higher voltage on the main battery. The indicator light turns from green to red.

If the sensor terminal is connected and the accessory operated then the indicator light turns to red.
When the twin start switch is operated both batteries will be connected together, hence bypassing the automatic isolation system. A heavy 'clicking' noise may be heard from the isolator as the switch is operated. The light turns green when operating.

Load Test Procedure

Connect a battery load tester (50amp) between the auxiliary terminal and earth. Run the engine at 1500rpm or greater so that the isolator is connected ie output above 13.6v. and the indicator light is green. Measure the voltage between the main and auxiliary terminals of the isolator. This should be less than 0.2-0.25 volts. Greater than this indicates excess resistance in the contact set - contact 4WD Systems.