mickeyw Posted April 10, 2013 Share Posted April 10, 2013 This project was initially inspired by another similarly titled thread, and particularly a post from Dave (TSD). Since the start of that thread I had looked up PTC heater to find out what one is and what it could do. I found one on the bay, and later found it was the same one used by Dave. Mine came from a Pug 307, but it seems that a lot of French cars use the same unit. Dave was good enough to email me his CAM drawings so I could make some drawings to work with. Essentially I shall be copying his design, but I shall endeavour to make a more detailed write up of the process. His info enabled me to knock up some mounting plates to hold the matrix in position in the LR heater box. I shall upload my drawings once I have corrected them , in case anyone else wants to try this too. This is how the brackets locate on the matrix. Well last night I battled to remove my heater box from the truck. Rust wasn't the problem, just my engine bay is a cramped place and the nuts and bolts are gits to get to. Here are the mounting brackets with the matrix between them, offered up the the heater to check the width was OK. Quote Link to comment Share on other sites More sharing options...
daveturnbull Posted April 10, 2013 Share Posted April 10, 2013 Looking good. I sense a potential market for these brackets, for those of us not lucky enough to have the kit to make them in our lunch break... Especially if the PTC heater is a fairly standard item from the scrappy. X-heater, anyone? Quote Link to comment Share on other sites More sharing options...
Aragorn Posted April 10, 2013 Share Posted April 10, 2013 Watching with interest! Quote Link to comment Share on other sites More sharing options...
TSD Posted April 10, 2013 Share Posted April 10, 2013 Looking good! There are quite a few more photos from my install, but I'm not sure if they would be of any help. If I get chance I'll upload them somewhere accessible. Dave Quote Link to comment Share on other sites More sharing options...
dantastic Posted April 10, 2013 Share Posted April 10, 2013 I really have to do this too. Just been on the 'bay and I have the same unit on order. The brackets, how did you make them? Would you be interested in selling a set ? Quote Link to comment Share on other sites More sharing options...
landroversforever Posted April 11, 2013 Share Posted April 11, 2013 I really have to do this too.Just been on the 'bay and I have the same unit on order. The brackets, how did you make them? Would you be interested in selling a set ? I imagine they were made at work Quote Link to comment Share on other sites More sharing options...
daveturnbull Posted April 11, 2013 Share Posted April 11, 2013 Would you be interested in selling a set ? + 1 here Quote Link to comment Share on other sites More sharing options...
TSD Posted April 11, 2013 Share Posted April 11, 2013 I imagine they were made at work Well, no, mine were made at home on my baby CNC mill They do take a while to carve out on a little mill though. I've stuck a whole load of pictures from my install here Basically it's all the pics I took from the first idea to the final install, so there lots of measurement photos that may or may not mean anything. Also beware there are two different heater boxes in the pics. Most of the measurement ones are of an early Defender heater (bent pipe type) but the install is on a late type (straight pipe). Quote Link to comment Share on other sites More sharing options...
dantastic Posted April 11, 2013 Share Posted April 11, 2013 Thanks for the photos TSD, any other 'lessons learned' or anything you would have done different in hindsight? I believe the heater is a 3 section heater, how did you wire it? all in one unit with one relay? While having the unit out, did you have a look at the fan motor at all? I recon the motor is really the weakest link in the heating system (once the engine is heated up). Quote Link to comment Share on other sites More sharing options...
mickeyw Posted April 11, 2013 Author Share Posted April 11, 2013 I imagine they were made at work Ross is correct, and I didn't do the machining either. Mine are made from Acetal plate. Dave made his from aluminium. It all gets down to what materials you have access to. Acetal is beautifully free cutting though. Having cut my heater box about last night and fitted the matrix I discovered a few mistakes I had made in the adapters, so a couple of 'professional fixes' have been made I took quite a few pictures and will post some later. I shall be wiring mine with the three circuits together, so just on or off. Something else I have been considering is to do with the fan speed. While we know the Defender fan isn't great, it does a fair job, but I find the low speed could do with being not quite so low. I measured the resistor for low speed at 2.5 Ohms. I figure that some experiments with other values may be worthwhile. I replaced the fan resistors on my RRC a while back with the pack designed by British Atlantic (sells for around £45). All this comprises is three 50W aluminium bodied power resistors mounted on an ally plate and wired up to the correct plug. (See this post) These resistors are available from all good electronics vendors for £2-3 each, and if you wanted to do your own assembly that job could be done for under a tenner. Anyway, back to the Defender - I have resistors in 2 Ohm, 1.5 Ohm and 1 Ohm to experiment with. I shall report my findings. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted April 11, 2013 Share Posted April 11, 2013 Don't forget Mickey you can also experiment with putting the resistors in parallel or series to give you even more values to play with. Quote Link to comment Share on other sites More sharing options...
mickeyw Posted April 11, 2013 Author Share Posted April 11, 2013 I think the difference between 0 Ohm for full speed, and 2.5 Ohm for the slower one is not going to matter quite where it ends up. I just think a wee bit faster would be helpful. For super high speed I think SimonR has a good idea with applying 24V, but then it would also be handy to have more than two speeds to play with. Other questions in my head: why is the RRC blower able to shift so much more air? Well for one, it has two impellers IIRC, then perhaps a more streamlined moulded ducting helps too. Other thoughts? Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted April 11, 2013 Share Posted April 11, 2013 I wasn't thinking about you having many different speeds but more along the lines of if the 1 ohm still wasn't fast enough you could wire the 1.5 in parallel to save buying another resistor for experimentation. Quote Link to comment Share on other sites More sharing options...
mickeyw Posted April 11, 2013 Author Share Posted April 11, 2013 I think the difference between 0 Ohm for full speed, and 2.5 Ohm for the slower one is not going to matter quite where it ends up. I just think a wee bit faster would be helpful.For super high speed I think SimonR has a good idea with applying 24V, but then it would also be handy to have more than two speeds to play with. Other questions in my head: why is the RRC blower able to shift so much more air? Well for one, it has two impellers IIRC, then perhaps a more streamlined moulded ducting helps too. Other thoughts? Following on from this line of thought, what is the likelihood of the motors have a different internal resistance? That would make them run at different speeds surely? Quote Link to comment Share on other sites More sharing options...
mickeyw Posted April 11, 2013 Author Share Posted April 11, 2013 Swapping this For one of these, is what I am on about. Quote Link to comment Share on other sites More sharing options...
mickeyw Posted April 11, 2013 Author Share Posted April 11, 2013 Anyway, getting back to the PTC: First I removed the coolant heater matrix. Undo the screws around the top, there is a similar plate at the bottom too. I also drilled out the rivets that hold the ducting that seals against the bulkhead. I don't think I took a photo of that, but you can see it removed in a couple of shots further down. Cut a hole in one side, and a matching one in the other. And you can slot the PTC element in. More to follow. Quote Link to comment Share on other sites More sharing options...
dantastic Posted April 11, 2013 Share Posted April 11, 2013 Do you need to tear the heater box apart? Looking at the images don't you have enough access without? You just need to cut the rectangular holes each side don't you? Or am I missing something here? Quote Link to comment Share on other sites More sharing options...
dantastic Posted April 11, 2013 Share Posted April 11, 2013 I've also ordered a 200A relay to switch it all in. I know it's a bit overkill but the 200A was cheaper than the 120A so....... I was thinking a timer button would be ideal for this. So press the button to switch in the relay for 5 min. Anyone seen any of them about? Quote Link to comment Share on other sites More sharing options...
mickeyw Posted April 11, 2013 Author Share Posted April 11, 2013 What I have yet to mention is that you need to have access to remove the air shut off flap that would normally occupy this space, and therefore need to open up the end of the casing to do so. I shall pop a photo up later. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 11, 2013 Share Posted April 11, 2013 Some thing like this? http://www.ebay.co.uk/itm/Timer-relay-board-adjustable-1-10-minutes-in-1-minute-steps-/121092285823?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item1c31a9a57f Quote Link to comment Share on other sites More sharing options...
TSD Posted April 11, 2013 Share Posted April 11, 2013 I had all three circuits wired together, with a single 80A solenoid. I used one of these, because they are reasonably priced and on past experience I trust them to be reliable. I've still got to find the time to take my heater box out again - I left out the packing piece that prevents air taking the easy route around the heater, so I'm not getting the full heating that's available. I suspect the main reason for poor fan performance in the defender is just the back pressure that the fan is blowing into. The fan sees a tortuous path into the dash, then the plenum is a fairly small volume with only 4 outlets, two of small diameter tube several inches long and two restricted with foam. Not sure I see an easy way to improve on that situation. I had two defender motors to choose from, they both seemed to run at much the same speed, so I fitted the least rusty of the two. I reckon the ultimate would be a custom fibreglass heater box design, using the fan from a dead Eberspacher cab heater - they can blow a gale through a tight restriction. ... or just replace the heater box with an Eberspacher in the same space of course - I have considered it. Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted April 11, 2013 Share Posted April 11, 2013 Interesting thread Mickey but I've got to say TSD's idea of an Eberspacher instead of a heater matrix has merit Good luck, looking forward to seeing how effective it will be. Mo Quote Link to comment Share on other sites More sharing options...
mickeyw Posted April 11, 2013 Author Share Posted April 11, 2013 Mo, I've been looking out for Eberspacher or similar for a while, the ability to pre warm the car is a distinct bonus. However this PTC element cost me £13, I already have the relay and have just spent another £10 mega fuse and holder. It will also take somewhat less time to fit than an Eberspacher Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted April 11, 2013 Share Posted April 11, 2013 .... petrol eberspachers seem to be a rarer beast as well ... and I can't see Mickey pulling up at the diesel pump Quote Link to comment Share on other sites More sharing options...
nicksmelly Posted April 11, 2013 Share Posted April 11, 2013 How many currents does the heater eat? Quote Link to comment Share on other sites More sharing options...
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