Isuzu Trooper Owners Club UK™

[diggerdave]

I decided to investigate my slightly feeble heating/cooling fan performance.  It was by no means awful but in the winter it was slow to warm up the cabin and in winter and summer the maximum setting was a bit weedy.

1) Replace thermostat!  Not a difficult job (plenty of excellent advice elsewhere - just open the housing and be prepared for a little bit of coolant to come out and splash on your driveway, not enough to merit a bowl unless you're fussy and easily topped up with some neat antifreeze).  Mine had a weak spring which meant that it was in effect too easily opened.  You couldn't see anything amiss by looking at it, but by comparing old and new by pressing on them you could tell.  This a) immediately improved heating and it now gets the cabin really hot in winter, and b)  made the engine run  quieter as it was previously never getting up to temperature - temp gauge now sits noticeably higher than before, a bit below half way.

Heating was fixed, but the fan was still weak.  I wrote it off for a long time as 'one of those things' until I fitted a new pollen filter to my partner's Focus when servicing it and I had a brainwave...

2) Change your pollen filter!  Who knew the Trooper had one?!  Other posts on here suggest not all have them but mine did (glovebox off with two screws below the hinges, two pollen filters live behind a 1" wide plastic housing, the front of which lifts and pulls out).  I haven't actually replaced them, just removed two filthy black cardboard lumps that might once have been filters.  Heater/fan now blows like a gale force wind, hot and cold.  

Thanks to everyone on the forum who's been there before and written up their advice!
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1998 3.1 Duty 1" lift with 265/75 Wrangler DuraTracs.  90,000 miles.

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