DIY: Replacing factory Espar heater with new off-the-shelf

[vanski]

Yes, if yours kicks off the hvac your Espar CU is not fried.

This a good data point. I’m almost positive the purple wire is landing on the second port available to turn on the hvac blower and the coolant pump.

Free that blower motor (very easy) and replace your aux pump and u should be in business.

 

[VinceP]

Would you try to free up the blower motor with espar in place and removing the cover? The attachment bolt under the Espar are quite rusty, I'm pretty sure they will break if I try to remove.

 

[vanski]

Yes. You can do it without removing the furnace from the vehicle although you will need to remove the headlight. Keep in mind it could be something else such as the flame sensor (although typically the start attempt is much longer than 3-4 seconds when it’s a fs)

 

[VinceP]

I know that first step will be the Fan, but there could be other surprises as the attempt to start sequence goes on. I will eliminate the fan and the coolant pump first, I will connect the Diagnosis wire to the 7-day timer, and we will go from there.

Thanks!

 

[Nautamaran]

I recently did mine, “mostly” in place - I took the mounting bolts out and tipped it on end to get inside the intake plenum. Access is good for taking the top off (remove the fuel line first). Getting inside the intake plenum to lubricate the fan motor requires removing the end plate and collar, which may be tricky with the unit bolted into te mounting bracket? Hopefully your bolts all turn... seems I had a pretty easy time of it.

-dave

 

[Patrick of M]

Would you try to free up the blower motor with espar in place and removing the cover? The attachment bolt under the Espar are quite rusty, I'm pretty sure they will break if I try to remove.

It is awkward and the little Torx head screws holding it together cannseize up to the point of even heat etc on a bench won’t get them out. You should try in situ, but if everything you need to loosen does not loosen, a length 6”of 3/4” pipe and some hose clamps can be used to bypass the coolant .

 

[kentonius]

Sorry for the delay my friends! Just took the Sprinter to Tecate Mexico and back! Great trip - only issue on the road was getting a hole in the upper turbo hose (the one that connects directly to the intake manifold). Found that out due to several indicators:

1. Engine load at or near 100% in a headwind - it wasn't like that before, so something was up.
2. Due to engine load, increased engine temperatures
3. Finally, LHM caused by over/under boost.

Inspected the hoses, found the culprit, Amazon Prime to the rescue and now a much better running, cooler engine! Another reason to have some sort of scan tool with these vans - almost a necessity!

Ok, back to the regular scheduled programming:

The violet and Brown should be the coolant pumps power supply.

If the ATC supplies a 12V+ on signal (yellow wire on external harness) then you can just wire that straight to the new D5. Then connect up the aux coolant pump directly to the D5.

Since the ground is common with the van, the purple wire may just go the ATC to trigger the coolant pump?

Some of the colors on the factory unit don't match my d5, however the pin-out is the same, just different colors for some wires.

I just did a quick test, and if I provide 12V to the van harness side of the secondary plug (purple and brown on the heater side), it engages the electric coolant pump AND the blower motor. When I remove the 12V, both turn off.

So, it looks like for the van to function as stock with the 7-day timer, Boost, and Rest, I need to have a +12V on that harness/wire whenever the heater is engaged.

 

[kentonius]

This a good data point. I’m almost positive the purple wire is landing on the second port available to turn on the hvac blower and the coolant pump.

Indeed it is. Now where do I connect that wire? Inside the Espar like the old unit? Or grab a 12V engaged wire from the van harness?

My belief is that with this question answered, I should be able to plug in the replacement unit and have it work in all functions, like factory.

 

[vanski]

Indeed it is. Now where do I connect that wire? Inside the Espar like the old unit? Or grab a 12V engaged wire from the van harness?

My belief is that with this question answered, I should be able to plug in the replacement unit and have it work in all functions, like factory.

Simply jumper the d+ dynamo wire from the vehicle side of the harness to that wire.. the one that leads to the 7day timer (the ‘switch’ wire) I believe the yellow one, but check the wiring diagram.

The purple wire leading to the atc relay is a signal wire. There’s very little load on it to drive that internal atc relay.

 

[VinceP]

Can't wait to read the next steps....

 

[kentonius]

So, we're 1/2-way there! I had time today to install the new espar in place of the old one. Hold-down bolts lined up, as did the intake and exhaust ports. Plugged the main harness in, connected coolant and fuel line. Started up the sprinter, hit the bacon button.... and NOTHING!

I was ready to give up as the temperature outside is dropping, when all of a sudden, I hear a ticking... then I see smoke, the sound of a miniature jet engine, and voila! It's alive! I'm guessing my fuel line was pretty dry and needed some time to pump enough fuel to the unit to get some combustion going.

I say we are 1/2-way, as I only tested this with the cold-start, engine running heater booster function. I still need to connect the old harness in to grab the +12v to engage the electric coolant pump and blower motor for the 7-day timer function.

To be continued...

 

[Patrick of M]

Sounds good, it’s great that it just plugs in, I have 3 DW5 Espars and each one has a different harness.. Fwiw the fuel feed can be primed if your Espar hasn’t run in awhile/you are installing one. Old school prime, if you know what it mean.

 

[vanski]

So, we're 1/2-way there! I had time today to install the new espar in place of the old one. Hold-down bolts lined up, as did the intake and exhaust ports. Plugged the main harness in, connected coolant and fuel line. Started up the sprinter, hit the bacon button.... and NOTHING!

I was ready to give up as the temperature outside is dropping, when all of a sudden, I hear a ticking... then I see smoke, the sound of a miniature jet engine, and voila! It's alive! I'm guessing my fuel line was pretty dry and needed some time to pump enough fuel to the unit to get some combustion going.

I say we are 1/2-way, as I only tested this with the cold-start, engine running heater booster function. I still need to connect the old harness in to grab the +12v to engage the electric coolant pump and blower motor for the 7-day timer function.

To be continued...

K: you’re 98% there. All that is left is lighting up that wire to the atc. At the hardware store you can acquire one of those snap on jumper terminals which connect with a male quick connect. Like this..... forgive me Sprinter source gods for I have sinned and put a url instead of an attachment as I’m on my phone.

If you look at the back of the 7 day timer you will see a plug with wires exiting. One of those wires will match the color of one of the wires leading to the vehicle side of the Espar harness. Hit the 7 day timer button and then take multimeter to the harness and see which wire gets 12v when you hit the on button on the 7 dt. Pretty’s sure it will be yellow, but I’m not 100%. After you’ve confirmed and jumpers the wire to the atc wire I’d slather some rtv or other sealant to prevent corrosion.

Thanks for confirming that heater works. I thought it would!

 

[220629]

... After you’ve confirmed and jumpers the wire to the atc wire I’d slather some rtv or other sealant to prevent corrosion.

Thanks for confirming that heater works. I thought it would!

Personally I would slather Vaseline or maybe your dielectric grease of choice rather than a sealant. Greasy products will creep and provide corrosion protection, and still allow easy future disassembly if needed. Sealants don't always seal (not enough surface area on wire insulation to properly bond), and make things difficult to take apart.

Thanks all for the information to date about generic Espars and T1N's.

vic

 

[kentonius]

K: you’re 98% there. All that is left is lighting up that wire to the atc. At the hardware store you can acquire one of those snap on jumper terminals which connect with a male quick connect. Like this..... forgive me Sprinter source gods for I have sinned and put a url instead of an attachment as I’m on my phone.

If you look at the back of the 7 day timer you will see a plug with wires exiting. One of those wires will match the color of one of the wires leading to the vehicle side of the Espar harness. Hit the 7 day timer button and then take multimeter to the harness and see which wire gets 12v when you hit the on button on the 7 dt. Pretty’s sure it will be yellow, but I’m not 100%. After you’ve confirmed and jumpers the wire to the atc wire I’d slather some rtv or other sealant to prevent corrosion.

Thanks for confirming that heater works. I thought it would!

It's always the last 1/2 mile that is the worst, isn't that how it goes? So I jumpered/spliced the wire, and on a cold engine, I pushed the bacon button on the 7-day timer. Immediately the blower motor and coolant pump kick on... and... nothing else. I suppose that there might be something else to check, but at 36 degrees and dropping, I wasn't in the mood this evening. I did confirm that it was the yellow wire on the van harness that gets the +12V to activate my separate plug.

We at least have a functioning espar booster heater, with the REST function ever present. Getting that last step of ensuring the heater will work independent of the engine running shouldn't be too difficult. Maybe I'm missing something else...

 

[Thanasis]

Kentonious, could you please clarify: in terms of wiring your new Espar, you just plugged into it the Sprinter harness to make it work with the engine running.
Thanks.

 

[vanski]

It's always the last 1/2 mile that is the worst, isn't that how it goes? So I jumpered/spliced the wire, and on a cold engine, I pushed the bacon button on the 7-day timer. Immediately the blower motor and coolant pump kick on... and... nothing else. I suppose that there might be something else to check, but at 36 degrees and dropping, I wasn't in the mood this evening. I did confirm that it was the yellow wire on the van harness that gets the +12V to activate my separate plug.

We at least have a functioning espar booster heater, with the REST function ever present. Getting that last step of ensuring the heater will work independent of the engine running shouldn't be too difficult. Maybe I'm missing something else...

True true on th last 1/2 mile! I’m there as well on helping someone install electrical...

Hmmmmmm. Start out by unplugging the Espar from the harness. Then hit the 7 day timer and test with a multimeter what lights up to 12v. You can use the brown wire pin as ground with your MM (not to insult you as I’m sure you know this). You’re just looking for that initial signal. I suppose that relay in the REST circuit could take a bit more though it shouldn’t though as the normal engine off mod is activated in a similar way.

Wondering if maybe that Espar possibly has an internal temp sensor like the newer ones where it won’t activate unless temps are < ~ 40f. This could possibly explain why it wouldn’t light up until temps got low (when you wanted to throw the towel to the next day).

I doubt this is the case as you have a true Euro model and they don’t have the same emission modifications as we do.

Step 1 is to verify which wire at the harness gets 12v when you activate via 7 day timer...

 

[kentonius]

Kentonious, could you please clarify: in terms of wiring your new Espar, you just plugged into it the Sprinter harness to make it work with the engine running.
Thanks.

Correct. I plugged the new Espar into the Sprinter harness as it had the same colors on the heater harness as my original heater. Since my Sprinter has the secondary smaller harness that was plugged in to the heater, it was as we discovered a +12V signal/on to enable the blower and electric coolant pump.

 

[kentonius]

Wondering if maybe that Espar possibly has an internal temp sensor like the newer ones where it won’t activate unless temps are < ~ 40f. This could possibly explain why it wouldn’t light up until temps got low (when you wanted to throw the towel to the next day).

Van outside temp sensor read 36 when I tried it... Unless somehow the internal temp was warmer than that? It had been sitting for quite a few hours, and I do agree the residual heat could affect it. It's another cold morning. I'll go try again!

 

[kentonius]

Step 1 is to verify which wire at the harness gets 12v when you activate via 7 day timer...

Have you found that the Sprinter harness energizes two DIFFERENT wires - one for the Heater Booster operation, and one for the 7-day timer?