S2 Cooling System - ABY Description

The cooling system on the ABY engine is identical in principle to that on the 3B engine. All of the mechanical components are in the same location but not all of the electrical components are...

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UPDATE in progress, but the words below are reasonably accurate. Keep watching for an update that will bring more detailed description and system checking tips whatever variant or year S2 you have at your disposal.

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Until I can get my hands on the ABY schematics, it will be impossible to document things thoroughly, but for now here is a list of known differences to the 3B system.

• The ABY radiator fan motor only has two terminals, unlike the three shown on the 3B. This leads me to believe that the ABY should have a different dump resistor network to provide for three fan speeds. Further investigation required, but given there are two hefty cables on the positive terminal of the fan I reckon one comes direct from the Hi-2 speed fan and the other from the dump resistors. Reckon on a three terminal dump resistor box hidden somewhere then...
• Fuses S5, S15 and S20 all claim to be the same as the 3B - further checking is required. But Fuse S21 on the ABY provides protection for the after-run relay (J155) - it is unclear if this fully protects for a short or seized condition in the TCP
• Relays J26, J101 and J138 all appear to be in same location as 3B, but J155 may not be