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MG TD TF 1500 - Arnolt Heater questions

Hey everyone,

I am back many months later with more heater questions. I have however (today) started to install my heater.

1. I mounted the Arnolt heater inside the car which I assume had been previously mounted at one time. The heater itself sits a tad to the right or towards the passenger side in a LH drive car. Is this by design so the driver has more foot room? Or did someone drill the hole in the wrong spot? There is no adjustment for this fit that I can see??

2. Where is the proper place to mount the rheostat (switch)? I have a bracket that I was told was correct but I can not find a place it looks right? ( I will provide picture)

3. Where is the proper place to find power for the rheostat/fan motor?

That is it for now, more to come I am sure.

Thanks in advance,

Rich

www.mgtd.co.nr

Rich King TD 8732

heater

Rich King TD 8732

Rich, the heater is generally centered on the gearbox tunnel. The only mounting screw is the one that goes up under the battery. Since the heater is not an OEM device there is no specific location for the rheostat. I replaced the rheostat with a lighted switch when I realized that I always had it on full blast or turned off. The knob next to the switch controls a valve at the back of the heater. See http://www.ttalk.info/Tech/Arnolt.htm for some info. Bud

Bud Krueger

Rich, since the heater was not a factory installation, most of the heaters are mounted where the installer felt they ought to be. As long as you are pleased with the location, so be it.
The switch is usually located where the owner has easy access to it. Your bracket might not be the one you finally use. Being a right angle type, there doesn't seem to be a simple mounting unless you want the switch facing the floor. I made a flat plate version that is screwed to the back side of the instrument panel. It also accommodates the control for the coolant flow valve. I will attach a photo.
Power can be tapped from any hot wire location or to the fuse box on the firewall. The main consideration is that you want to have it fuse protected. I used an inline type.
Because I wanted the heater to shut off with the ignition, I added a relay so as to keep from overloading the ignition switch. The relay was cheap on line from China (the common source) and does the job very well.
I will add photo in a second response due to limitations here on the BBS.
I am sure other guys will have additional thoughts about your questions.


Jim Merz

The relay is located on the cockpit side of the tool box with a short wire to the ignition. The relay feeds the power to the heater and my radio.

Jim Merz

I ditched the rheostat switch in favor of a toggle off/on . I pulled power from the from the fuse terminal.

MG LaVerne

Thank You, awesome information so far, I have yet to actually connect to the water lines, so my next question is: Many of the applications I see have a inline valve as mentioned in the above posts. I don't understand this. I have read that some people shut off the valve in the summer to prevent hot water from the engine circulating through the heater. If you have a valve that you shut off how does the water circulate through the engine? My understanding is that the heater system when added just creates a longer path for the water to flow.

Rich

www.mgtd.co.nr
Rich King TD 8732

Rich, it's a function of your heater plumbing. Did you use the Arnolt bypass fitting? I don't know of any heater plumbing that goes directly into the coolant flow. All that I know of are really in parallel with the flow. They really add an additional flow, rather than a longer flow. Jim Merz and I have a valve behind out heaters that we can control from the driver's seat. Bud
Bud Krueger

I have a water shut off valve behind the heater. Thats what the choke cable is for on sub panel.

MG LaVerne

LaVerne, I love your valve. Mine is under the hood, operated by turning the knob on the valve. I have an Arnolt in the TD and an Eureka in the TF. Do you have part numbers and a source for these parts, valve and cable?
Thanks,
David
D. Sander

I'd have to look through the receits David. I gave it to Dave DuBois not long ago. He may pop in. The valve came from NAPA... I think was for a Toyota application...about 15 bucks. Any solid wire choke cable will do the job. You can pick those up at NAPA as well. The ones I had actually came on the TD and TF and were just laying here after I replaced them with the correct cables.

Same valve used on the Mojave heater in the TD.

MG LaVerne

Center knob for the water control.

MG LaVerne

Are you talking about this Arnolt bypass fitting? Then Yes I will be using it.

Rich King TD 8732

Rich, I attached my heater to a piece of black painted plywood and hung the plywood from the scuttle frame tube (?) with a pair of adel clamps. The mounting board is invisible from the occupants in the car. For a switch I took bud's idea about the rheostat always being on high so I installed a momentary on/off push button switch on an "L" bracket behind the instrument panel to the left of the turn signal switch..completely invisible install and out of the way of both driver and passenger's knees. I used an inline fuse with a pickup off the switched side of the key. I have yet to install a heater valve...after 4 summers of driving I think the odds of me installing one at this point are fairly slim.
Regards, Tom
tm peterson

Rich, here are a couple of pictures of the mounting bracket for my Arnolt Heater. As Bud mentioned, my heater only has one mounting bolt in the middle of the battery base. There is plate that the heater slides onto to help supply support. I have other pictures if it would help but these are probably more than you would like.

If I can in anyway be of further help, please let me know.

Patrick

Picture 1 of 3

Patrick Earles

Picture 2 of 3

Patrick Earles

Picture 3 of 3

Patrick Earles

Nice shots, Pat. Rich, you can readily see how the lip on the mounting bracket slips into the slot on the underside of the toolbox. You can check the gearbox fluid level with the Arnolt mount. Bud
Bud Krueger

Thanks for the help guys, I hope to have the heater completely up and working by the weekend! :)
Rich King TD 8732

My dad has a spare engine at his house and he found a home made cap for the head that someone put together for a heater. This would be a clean install but would it work? Would you get proper water flow through this fitting? What do you guys think? Photos included.

Rich King TD 8732

If that is both an inlet to the heater and the return - Short answer is no - it won't work. You need the differential pressure of the pump to get the water to flow through the heater. You have the Arnolt pipe fitting [shown above] which feeds the heater from the bypass and the return goes to the bottom side of the rad. [Other side of the thermostat] Now you will get hot water quicker - even with the Thermostat closed. Water will flow through the heater.
On my TD the heater feed comes from the bypass tube and returns to the rear of the head and it works OK. Saves a bit of pipework around the Engine, but I think the lower Rad location is the best solution.

Rod
R D Jones

This thread was discussed between 20/04/2014 and 29/04/2014

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