Series 3 heater AWOL

Hi All,

Newbie, to the forum but not to old Landys.

Wonder if anybody might know the answer to this, I've got a Italian market spec. '79 109 station wagon in generally good shape, with original panels, and chassis with no rot, couple little rusty spots in the bulkhead (for future fun). So basically a decent straight, original one.

My heaters were working fine, until they just stopped (whilst in use). So I replaced every fuse (both in the fuse box under the steering column & the fuse box under the bonnet), which changed nothing. I dug around online and found a few people talking about bad switches, so got a new Lucas switch and swapped that out too. No change.

I've got a manual, but there's no heater circuit shown on the wiring diagram(!) So before I get out a test light and put aside a morning for digging around all the nooks and crannies. Is there a hidden inline fuse somewhere, or a relay? Anything that anybodies already found to be a typically thing to crap out in the heater circuit?

Oh, and maybe it's not relevant, but in the off position, all is silent, as it should be. Then when I switch the blower switch to low setting there's a (very) faint whirring noise, but when I flick it down to full speed heater fan, silence returns. I found that it does this with both the new switch and the old one.

Any one? I'd be very grateful for a solution that doesn't involve faffing about all Saturday morning.

I'VE had that kind of problem. Check the rheostat gismo beside the heat exchanger. If the soldered connections are rusty it causes intermittent fault. I'VE had exactly same symptoms n re-soldered the connections no problems since.

Thanks John, then it's worth a look there first.

Digging around online, it seems that there's an inline fuse too (inline only because the heater was optional, so the theory goes) but the only mention I ever find is that it's "behind the dashboard". So whether that means behind the instrument console (which only means pulling off the steering wheel and the actual console) or whether that means pulling off the whole dash, I guess I'll find out...