Hi Low Ranger, yip, it's a tight fit all right. Interestingly my car has an ARB compressor on the drivers side so it's a mirror image to your planned installation. Also there's a high capacity relay there for connecting the 2 batteries together although normally I run the second battery off an ETI design (Jaycar kit) battery charge controller which is mounted just behind the main battery - I have a switch to select controller / isolate / parallel through relay for the second battery.
I should add that I'm considering changing the controller to a Traxide SC40 unit as the ETI design doesn't seem to keep the second battery up to full charge all the time for some reason.
GrahamH
'65 SIIa 88" Hard-top, Rego DW622, 186 Holden, 4.3 diffs (she's still back in NZ)
'88 4-door Rangie (long gone)
'96 Disco SI 3.9V8i (LPG) Manual (Inspector Rex's kennel)
'03 Disco SII TD5 Auto (the serious camping car)
'15 Disco 4 3.0Lt TDV6 (was a dog-hair free zone - not now!!!)
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