white90 Posted April 23, 2007 Share Posted April 23, 2007 Hello! I dont know the X-Charge system, but all split charge systems basicly functions more or less the same way. Some kind of signal is used to trigger a solenoid so that the main battery and aux battery is joined together. The signal for this solenoid can be taken from the alternator - or from any ignition switched supply. Taking the signal from the alternator is probably the best. If you take the trigger signal from the alternator then the two batteries will only be joined together WHEN the alternator is charging. If you take the signal from an ignition swithed supply the two batteries will be joined together whenever the ignition key is turned - regardless of the alternator is charging or not. By taking the signal from the green wire going to the rear wiper you have effectivly created a ignition switched split charge, instead of a alternator switched split charge system. (Green wires are ignition switched according to wiring standard BS-AU7 - se below for full list) On the alternator you will find at least three terminals, the big B+ where you connect the positive lead from the battery (joined at common point on starter solenoid) and the W+ where you connect the tachometer and the D+ where you connect the charge warning lamp. The D+ is actually a lower rated "copy" of the B+ circut. The main purpose of the D+ circut is to provide input current to the regulator and to provide a positive feed for the charge warning lamp. The charge warning lamp is on one side connected to the positive terminal on main battery, on the other side connected to the D+ terminal on alternator. When the alternator is not running, the regulator effectively shorts the D+ and field windings, thereby running a current from the positive battery terminal over the charge warning lamp to the alternator field windings and from there to vehicle earth. The charge warning lamp will then light up. When the alternator is running the current provided from the main battery terminal will exite the field windings, and the alternator will begin to produce current. The charge warning lamp will then receive a positve feed from both sides which is why it stops to light after a few seconds after the engine is started. The D+ terminal is therefore important for any split charge system, in providing a definitive signal for when the alternator is running. Best practice is to connect the two wires ON the D+ terminal on the alternator. Then the modification is clearly visible for all others doing repair work to the car. The wire should (of course) be fused. 5amp fuse will be more than enough. The two batteries (main and aux) should have common ground (vehicle earth) A low cost split charge system can be made using a small 30 amp automotive solenoid. Terminal 86 on the solenoid shoud be connected to D+ on the alternator. This wire will only provide a small current to trigger the solenoid so can be made from 1.5mm2 cable and should be fused with a 5 amp fuse (as close to the alternator D+ as possible) Terminal 85 on the solenoid should be connected to vehicle earth (1,5mm2 cable will do fine) Terminal 30 on the solenoid should be connected to main battery positive terminal. 30 amp fuse as close as possible to the positive terminal on battery. Use 6mm2 cable. Terminal 87 on the solenoid should be connected to the aux battery postive terminal. 30 amp fuse as close as possible to the positive terminal on battery. Use 6mm2 cable. The two batteries should both have their negative terminal connected to vehicle earth. Full list of BS-AU7 colour codes included for reference purposes: BS-AU7: ========= Black: All ground connections Black/ Purple: Temperature switch to warning light Black/ Green: Relay to radiator fan motor Black/ Light green: Brake switch Black/ Light green: Brake differential pressure valve to warning light Blue: Headlamp connections Blue: Headlamp switch to dimmer switch Blue White: Headlight high beams Blue/ White: High beam dimmer switch to high beam indicator lamp Blue/ White: Dimmer switch to long-range driving light switch Blue/ Red: Headlight low beams Brown: Main feed from the battery. No switches or fuses Brown/Yellow: GEN to volt. Regulator Brown/ Blue: power feed to headlamp switch Brown/ White: Ammeter to main alternator terminal Brown/ Yellow: Long-range driving light switch to lamp Brown/ Yellow: Alternator to 'no charge' warning light Brown/ Purple: Alternator Regulator feed Brown/ Green: Fuse to horn (No relay) Brown/ Lt. Green: Windscreen wiper motor to switch Brown/ Black: Horn to horn button (no relay) Green: Ignition switch controlled wiring for auxiliary devices, eg wipers, flashers, etc Green/ Black: Fuel gauge to fuel tank unit Green/ Blue: Water temperature gauge to temperature sender unit Green/ Brown: Switch to reverse lamp Green/ Red: Direction indicator switch to left-hand flasher lamps Green/ Purple: Stop lamp switch to stop lamps Green/ White: Direction indicator switch to right hand flasher lamps Green/ Yellow: Heater switch to slow speed on heater motor or for single speed motor Green/ Gray: Heater switch to high speed on heater motor Green/ Orange: Low fuel level switch to warning light Light green: voltage stabilizer to instruments Light green/ Black: Windscreen washer switch to motor Light green/ Blue: Flasher switch to left-hand flasher warning light Light green/ Brown: Flasher switch to flasher unit Light green/ Purple: Flasher unit to flasher warning light Light green/ Orange: Rear window washer switch to motor Orange: Wiper circuit Orange/ Black: Wiper switch to to motor parking Orange/ Blue: wiper switch to low speed on motor Orange/ Green: Wiper switch to high speed on motor Orange/ Yellow: Rear wiper switch to rear wiper motor Orange/ Light green: switch to rear window motor parking Purple: Accessories fed direct from battery via fuse (Always live) Purple/ Brown: Horn fuse to horn relay when horn is fused separately Purple/ Red: Switches to map light, under bonnet light, glove box light and boot lamp when fed direct from battery fuse Red: Tail lights, instrument lights, parking lights and side markers Red/ Yellow: Fog light switch to fog light or front fog light fuse to fog lights Red/ Blue: Front fog light fuse to fog light switch Red/ Brown: Rear fog guard switch to lamps Red Orange: Power to rear fog guard lamp fuse Red/ White: Fuse to instrument lamp switch, Instrument panel lamps White: Ignition circuit, no additional switches, not fused White: Power to coil White/ Black: Ignition coil to distributor White/ Black: Distributor side of coil to tech impulse sensor White/ Brown: Oil pressure switch to warning light or gauge White/ Pink: Ignition switch to radio fuse White/ Red: Ignition switch or starter switch to starter solenoid Yellow: Generator connections wired through the ignition switch Yellow/ Green: Dynamo 'F' to control box 'F' Alternator field 'F' to control box 'F' 1 Link to comment Share on other sites More sharing options...
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