The Dispatch | Expert | Scudo Hub

I recently had to change my heater matrix because it was blocked. When I turned the heating on in the van, it would blow tepid air into the cab even when the engine was at 90C. I figured it was a problem with the heater matrix rather than the thermostat or coolant, because the engine was staying at the right temperature and the flow and return pipes to the heater matrix were getting hot. I managed to reach into the heater box and feel that the heater matrix itself was cold. More info on Reddit. Here are some photos from me changing the part. The vehicle is a 2018 Peugeot Expert mk3 van.

For starters, you can reach the heater matrix from the passenger footwell without removing any parts. This is useful for feeling the pipes etc, but there isn't enough space to actually remove the matrix. For that, you need to take out a huge amount of dash. Around 10 panels. The part that I'm pulling off in the photo below has a narrow plastic loop that goes behind the gear stick assembly. To get this off properly, you would have to briefly remove that, but instead I just cut through the plastic loop with some snips. Bit of a bodge, but I don't think the plastic loop was doing anything important. The red circle in the photo shows the heater matrix location.

Here's a photo of the heater box with enough dash panels removed to see it properly.

Here's a close-up, showing the two black clips that secured the flow & return pipes to the heater matrix. You need to remove these clips. I found that a jamming a flat-head screwdriver in there and twisting did the job. If you intend to reuse the clips then of course be careful. Fortunately, the replacement heater matrix that I bought came with new clips.

Now would be a good time to mention the importance of doing this job when your coolant is cold and your coolant system is de-pressurised. I was very stupid and did this just after driving, so I got a face full of warm coolant when the pipes came off. Fortunately, it had only been a short drive. Had it been a long drive and the coolant been hot rather than warm, I would be in hospital. Embarassing. If you want to check that your coolant system is de-pressurised, you can undo the bleed screw, which is found on the heater matrix pipes as they go through the fire wall, on the engine bay side.

In case you're struggling to get those clips off, this photo shows how they are held together.

Finally, you can push the heater matrix pipes out of the way and pull out the matrix. There are no fastenings holding it into the heater box, so it slides out easily. The difficult bit here is pushing the pipes out of the way while simultaneously pulling the matrix. The pipes are quite stiff.

And lastly, in case anyone is interested, here are some pics showing how the heat control door works. This is the door that the heater box moves to control the temperature of air blown into the cab. I tried to turn these into a gif so you could see it moving, but I think the forum doesn't like gifs. In these pics, I have removed the heater matrix and the little 'viewing' panel in the side of the heater box. When the blend door is in one position, all air is forced through where the heater matrix would be. When the blend door is in the other position, air is forced over the AC matrix, which is positioned further back in the heater box and barely visible in these photos.

Here are my notes from installing a leisure battery & DC-DC charger in my 2018 Peugeot Expert Mk3. Its a very simple setup where the leisure battery is charged only by the alternator. There is no solar and no mains hookup. I shall spare you the detail of how I chose all my components; there are lots of articles describing this process elsewhere. However, I will put a list of components below.

Leisure battery: 100Ah LiFePO4 from Eco-Worthy
DC-DC charger: Victron 12/12-30A DC-DC Non-Isolated
Big charging cable: 16mm^2 cable
Big terminals: copper tube terminals with 6mm holes
Big fuses: 60A midi link fuses
Big isolator switches: 100A isolators
Fusebox: this cheap eBay one

As seen in the wiring diagram above, everything is grounded to the chassis to reduce the amount of black cable I needed to buy, and to reduce the number of holes I needed to drill. Of course you can, in principle, ground things to any part of the chassis, but I chose to use the existing grounding points made by Peugeot. I figured these guaranteed a good connection and saved me from having to grind paint off other parts of the chassis.

The first step was to find a route from the starter battery in the engine bay to the cab, where the leisure battery and charge controller would be installed.

And then the fusebox connects to my lighting, ceiling fan, diesel heater etc...

I initially posted about this on Reddit but this forum looks a lot better so I'm repeating myself here.

I'm trying to wire a second central locking button. This is the dashboard button (shown below) that you can press to lock/unlock the van when sat in the cab. I want to keep this button as it is, but add another one in the rear of the van that does the same thing. The van is a campervan conversion, so I want to be able to lock/unlock the doors while laying in bed in the back and while sat in in the cab in the front.

So far, I've pulled the dash off and unplugged the cable running to the back of the button. In case anyone else wishes to do this, I'll put a picture below. Its a right pain to get this cable off since you have to reach in quite far with your hand and you can't see what you're doing. You have to feel for the tab thing I've labelled and push it into the connector to release it.

And so here is the connector that I've unplugged.

So now I must work out what these four wires do. Clearly, one of them is earth. I expect that another wire powers the light on the button (see first image). Possibly, the van central locking is activated when the remaining two wires are connected? Would love to see a wiring diagram of the button. I think I will just buy a spare and experiment with a multimeter & continuity tests, but I would appreciate any advice that folk may have?