Heated rear window ..... & offside rear fog light

[Morris Montego]

It's been a while since my last ask for advice but I've noticed today -

First thing, taking Morris for a drive I decided to test all four of the dashboard switches cited below the clock. All fine apart from the heated rear window switch. The switch itself would not illuminate as it should when I depressed it. There was no discernible on/off in the switch action either - Is this as it should be? I've changed the fuse but switch still won't illuminate. The illumination of the other 3 switches is all ok. This morning, the very mild mist on the rear screen did quickly clear but I think general cabin warming caused this.


Also, I noticed this morning when pressing the rear fog light switch, BOTH lights did illuminate. I tested again this evening and now the offside light ain't working. Hmmm, I only changed this bulb in the summer.

[Doctordiesel77]

The heated rear window switch doesn't latch in iirc, it just switches on a timer relay down by the fuse box, I think warning light is fed direct from relay output, so either blown bulb, blown fuse, or faulty relay. If you switch lights on, then switch HRW on you should see lights dim a bit. The warning light is quite handy, heater on with one press, off with second press, or when timer turns it off, without the warning light it is sometimes hard to remember if heater is on or off.. The fog lamp could just be a corroded connection on the rear light assembly? good luck!

[Morris Montego]

So, you reckon it's just the light, the heated rear window itself most likely working?........It hasn't been misted up enough yet for me to tell
The connections at the screen are fine.

[Jeff Turbo]

Just test with a multi meter, switch on and you should have power

[Morris Montego]

........I do have a simple circuit tester

[grogee]

My HRW bulb failed as well. It's on the long list of winter jobs to fix. HRW itself is working fine luckily.

[Morris Montego]

A bit of early morning Montego time, circa 7:45 start ......and -

Changed the offside rear fog light again - the bulb didn't appear blown but I put a new one in anyway. Connections all seemed fine too. Illumination once more.

My circuit tester at the heated rear window.....it showed no power. Likely causes, given fuse already changed are??

[Doctordiesel77]

My circuit tester at the heated rear window.....it showed no power. Likely causes, given fuse already changed are??

The relay/timer or the switch, relay is in fusebox, so easiest to get at, if the switch is gummed up a bit of rapid switching on & off might get it working.

[Morris Montego]

Is a replacement relay relatively easy to source?

[Morris Montego]

Which is the heated rear window relay?

[Morris Montego]

......and, thinking perhaps a "gummed up" switch, I have noted that the rear screen wipe (only) button is a bit temperamental - sometimes it comes on, sometimes it don't. Also, the handbook says it will operate continually at first, ten wipes, then switch to intermittent wipe. I just seem to get a single wipe.

[Morris Montego]

.....the wash wipe seems fine

[Jeff Turbo]

The rear fog lamp could be due to the connections in the cluster. Might a clean with an emery cloth and a small adjustment. The switches they maybe faulty try using electric contact cleaner and keep switching on off. Remove the switches first though and let the cleaner dry before re-attaching

[Morris Montego]

Removing switches requires removal of instrument binnacle surround doesn't it? May be a bit tricky replacing given slight (repaired) dashboard cracks and notable mis-shaping of fascia moulding ahead of the driver

[Doctordiesel77]

Which is the heated rear window relay?

It is just out of shot on that photo, top right (opposite the inside lights one) if it is the same as the one in the book. Probably worth checking on the fuse map though. The rear wiper controller is on the other side of the board, so not easy to get at/see.