Webasto install HDJ81

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I Tee'd into the factory fuel line for ease of installation and so far it works flawlessly. Contrary to what is mentioned in a previous post, the barb fitting size for the factory fuel line is not 3/8" but 1/2" and the barb fitting for the Webasto fuel line is not 1/4" but 3//16".
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Due to the lack of space beside the heater, I mounted the fuel pump on the fire wall, using existing threaded hole.
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The exaust is fastened via stainless zip tie thru holes in the heat shield and a S.S. bracket on the inside of the fender.
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I used the 7 day timer to operate the unit and mounted it under the factory diff locker switch.
 
Hi,

I have installed the webasto Thermo Top C in my HDJ81. Thanks to the information here the install was fairly straightforward. Heater is working, however I’m not really satisfied with the efficiency. Current temperatures at night are around -2C to -5C and in the morning after 1 hour runtime the cluster gauge needle is just a bit above the C line.
It certainly makes a difference with the cold start, however I was expecting to have operating temperature after one hour runtime especially at these mild outside temperatures.

I have read that moving pin 3 to 1 will increase webasto output, but before I try that I hope you guys can help clarify some of the things I have noticed:

1. I have got an air pocket in my webasto filter (around 15-20%). Is that normal? If not any idea how can I get the air out?
2. The temp needle drops a good 30-35% once I fire up the engine. I can’t logically explain why.
3. My cabin heater turns on only if I have the ignition on. I thought it is thermostat operated, but looks like it is not (unless I have got something faulty:). Is this common with all 80 series? Im thinking to install a relay to control the blower or an aux fan so I can heat the cabin prior engine start.

Thanks!

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oszkari said:
1. I have got an air pocket in my webasto filter (around 15-20%). Is that normal? If not any idea how can I get the air out?
2. The temp needle drops a good 30-35% once I fire up the engine. I can’t logically explain why.
3. My cabin heater turns on only if I have the ignition on. I thought it is thermostat operated, but looks like it is not (unless I have got something faulty:). Is this common with all 80 series? Im thinking to install a relay to control the blower or an aux fan so I can heat the cabin prior engine start.

Thanks!

View attachment 1565304View attachment 1565305
Click to expand...
1. Not an issue
2. It's not hot enough to open the thermostat is my guess, once the engine starts the thermostat opens and the cold coolant from the radiator is mixed in
3. Normal, the sensor that controls the heater fans does not work unless the ignition is on
 
Make sure you leave your HVAC set to full hot, BEFORE you shut the truck off when you're parking it, as it's electronically actuated, not cable, this lets the coolant circulate through the heater core while it's warming, giving you instant heat for defrosting.

I've read that there is a pin on the Webasto you can switch that ups the output, but I haven't done it and I don't have details on it.
 
According to that document, these things max out at 77C on the high setting, which I don't think will be enough to open the t-stat, so that's not supposed to happen, you'll never achieve full operating temp.
 
Was able to hook my Webasto up to trunk option on the Arctic Start 2X in my truck. Unfortunately, I had to have this done at a dealer because the programming software is proprietary. Now, when I hold down the trunk release button the Webasto will kick on for 20 minutes. There is no way to turn it off so if I start the truck and drive away it will continue to run until the 20 min interval is up.

35F this morning in Chicago and 20 min was plenty to have the truck warm when I started it. When it gets colder I may need more time to will just have to hit the trunk release again after 20 min.

FYI - I am not using a Webasto timer.

Hope this is helpful.
 
IanB said:
According to that document, these things max out at 77C on the high setting, which I don't think will be enough to open the t-stat, so that's not supposed to happen, you'll never achieve full operating temp.
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It's close to full operating temp. I think it opens the thermostat enough to circulate through the rad, when I first did it (a few years ago now) I recall checking things over with an IR temp gun and the entire coolant system was warmed with just the Webasto.
 
Douglas S said:
1. OK. That is a relief!
2. Sounds logical, most likely that is what is happening. Are you talking about the thermostat in the engine block?
3. Did any of you guys hook the webasto control to the cabin blower? I read somewhere that the blower is taking lots of Amps so would be great to have some feedback before I start messing around.
Click to expand...
 
efjay6tee said:
Was able to hook my Webasto up to trunk option on the Arctic Start 2X in my truck. Unfortunately, I had to have this done at a dealer because the programming software is proprietary. Now, when I hold down the trunk release button the Webasto will kick on for 20 minutes. There is no way to turn it off so if I start the truck and drive away it will continue to run until the 20 min interval is up.

35F this morning in Chicago and 20 min was plenty to have the truck warm when I started it. When it gets colder I may need more time to will just have to hit the trunk release again after 20 min.

FYI - I am not using a Webasto timer.

Hope this is helpful.
Click to expand...

That is something I'm looking into as well. I have got an ebay wireless remote + relay, I need to do some reading on how to hook it up.
 
oszkari said:
That is something I'm looking into as well. I have got an ebay wireless remote + relay, I need to do some reading on how to hook it up.
Click to expand...
I used an ebay remote and wireless relay as well. I just wired it in parallel with the switch and tucked it behind the dash. Works great.
 
anyone running something like this ...
76AF1ADC-0EF1-427B-87F1-A3BB1CBEB1C5.png


i’m looking to set something like this up but most of these run off gsm sim cards and in canada there’s only one network that carries one and it has crap coverage. i need a cdma one. just looking to see if anyone has experience with how well it might work
 
oszkari said:
I moved the pin, since then the webasto turns off after 4 minutes. Moved the pin back, same behaviour. Timer shows webasto is running but the unit in nfact is shut down.
Click to expand...
Are you making sure that the heater valve is all the way open when the Webasto is running? This has to be done before you shut the truck off.
 
I managed to get my webasto work again. As part of the troubleshooting process I removed the fuel line from the Webasto fuel inlet and turned the webasto on. Although the fuel pump was ticking and the filter got visibly full (-10 to 15%) no fuel was coming out of the hose. After 4 minutes webasto shut itself down. I turned it on again and this time I started to have fuel sprinkling out from the hose.

What I did notice before I started to troubleshoot that my filter was about 50% empty before webasto pump turned on and filled up the gap. I'm not sure if it was the sudden overnight temperature drop (0 to -20c) or the pin change that caused my issues. Anyways I have re tightened all my hose clamps just to make sure no air can get in. I will attempt the pin move again once I receive my webasto diagnostic tool.

Is it safe to use the truck manual priming pump to get the air out? The webasto fuel filter and pump are uni directional, could the primer do any damage?

Thanks!
 
Glad to hear you got it figured out. If I have my fuel system bled down for whatever reason I use my pusher pump to prime things back up. I can't imagine using the manual pump would hurt anything.

It was -20C yesterday morning so I used my Webasto for the first time this year. I still think it's the best money I've spent on my truck.
 
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