So on my silver P38, RL7 is looking rather crispy, and the passenger side blower isn't running at all. Whether it is the relay or blower at fault, I plan to swap the fusebox with the one from my breaker that looks in better condition. When I disconnected it though from the old car, I noticed the blue connector had clearly gotten a bit hot on one pin too. I guess this will be the same on the silver car.

I'm assuming this pin is fed by RL7, though I haven't cracked out the multimeter to confirm this yet.

If it is, my plan is to cut this wire out of the blue connector, extend it slightly and mount a decent relay externally, fed from a new fused feed from the battery. So the only feed from the fusebox is the ground/positive for the relay coil. I know recently a similar idea was posted up on the other forum, but it seems to me that it would be better to bypass the not so great fusebox tracks / connectors altogether.

Anyone foresee any issues?

If you are going to swap the fusebox, check the VIN on the two cars as there are a number of different ones. My SE has a brand new fusebox and I was going to swap it into the ex-plod until I checked. Although they are only a few months apart (SE is a late '97 model and the ex-plod is a '98 model but built Nov '97), the fuseboxes are different part numbers.

Oh I could have sworn I only saw one on Island4x4, looking again though, quite a few options.

Hmm. Well I guess that doesn't really affect my RL7 plan if they're not the same. Will have to see if the heated windscreen fault lies elsewhere, stopped working completely again.

Elec Heated screen uses a different set of relays (4 and 5) and fuses (30 and 32) etc. RL7 is just half of blower motor circuits. Can't post pic easily at moment but RAVE ETM F6 has circuit diagram (page 176 of 611 in my copy):

• This operates only with the engine running, which is
• determined by the HEVAC panel. In the off state, the
• signal is at 12 volts. When the Heated Front
• Windscreen is activated, the signal is switched to 0
• volts. This provides the ground required for relay 5 to
• be pulled in, as there is an ignition feed on the other
• side of the coil provided by relay 15. This relay
• energises one half of the heated screen elements.
• Once relay 5 has been energised, a 12 volt signal is
• provided to the coil of relay 4. The other side of the
• coil is connected directly to ground, thereby
• energising the relay and switching on the other half
• of the elements.
• There is also a feed spliced from the harness which
• provides the petrol Engine Control Module with a
• signal that tells the unit there will be a large electrical
• load turned on/off.

Mmm I'd seen it uses a pair of relays - I was hoping my issues were just the box as I know the one from my breaker is fine.

The drivers side of my screen mostly works(ed), but the entire passenger side from the middle of the screen onwards doesn't do a thing. Now the drivers side has stopped completely too. I need to take the scuttle panel off to check the connections under there and fit some mesh etc, so I will check for voltage with the meter at the same time. Fuses are good though I can't remember now if I've swapped the relays or not to rule them out.

More to look at this weekend!

The first relay deals with the passenger side and also switches the second relay which is for the drivers side. So if the passenger side was working but not the drivers side, it could be the second relay. Mine used to work on the passenger side but only a few strips on the drivers side

Last time I tried it, I'd got a few strips on the passenger side and one thin strip down the middle of the drivers side. I think the problem is more likely to be at the top or bottom of the screen itself where the connections are no longer making.

Oh bummer :(

Well I suppose if I can get the other blower going and free up the flaps that will make things easier in the cold, the V8 warms up quickly enough anyway!

Check the ground straps for the heated screen. They are under the cowl. You will have to remove the wipers for access.

I've had a replacement foam thing to go in there for months (added it to an order from Island because I could) and haven't got round to fitting it so I'll be getting in there sooner or later anyway. I'll see if I can see how the element wires are commoned together and if there is an obvious way of remaking the connections. Maybe slobbering a load of the conductive silver paint sold for repairing PCB tracks and heated rear screen elements will do it?

Mmmm I meant to order some mesh this week to do that job as Marty has done. Last time I had the panel off the old car, I remember seeing two connections in the middle of the screen at the bottom, not sure if the other connections are at the opposite ends or at the top somewhere.

I had my screen replaced some years ago and watched them. As far as I can remember the connections are only at the bottom . Im not sure if they are attached to the screen or maybe replaceable as they actually left the old ones in my car.

My old screen was doing the same and sporadically heating. I had a stone chip that turned into a crack right across the screen on a cold day.
£60 excess from my insurance company I got a replacement screen.

The positive connections are under the outside scuttle panels/plastic plenum covers - whatever you want to call them, and they are waterproof connectors.

the ground feed is common between both halves in the middle of the windscreen and connects to an earth stud. which has been known to corrode and part company with the vehicle. It can be repaired by cleaning up all the contact surfaces and using a nut/bolt to reconnect the grounds to the bodywork.

Just seen Wickes do some 6mm galvanised wire mesh. That and some black spray paint will do nicely.

Hopefully it'll be the case of poor connections - seems odd the whole drivers side suddenly stopped too. Many heating/cooling related things to look at tomorrow!

So the bad news is, my heated windscreen has just failed altogether now. Got power at both sides and the ground is okay etc, but nada. Not drawing any current at all. Oh well. And I've found an LPG gas leak -_- Thought I kept smelling it, those stupid use once hose clamps... the only one remaining on the vapouriser has come a bit loose. Tomorrow's problem.

Good news is my passenger side blower is fine, it was just RL7 / the fusebox causing the problem. I've cut the wire to the blower off from the blue plug under the fusebox, and mounted an external relay with a new feed. Relay is just mounted with number plate tape for now - it is surprisingly strong stuff. Annoyingly I had nothing to crimp to extend the wire, so I have two fuse holders...

Oh and for anyone wondering, a blower on full pelt draws about 17 amps with a clean pollen filter.