I think I found a heater booster, but no switch

brutimus

Member
I stumbled across a thread last night saying that nearly all T1N's shipped with espar heater boosters. I'd previously noticed the little silver muffler in the front driver's side wheel well and didn't know what it was. I just went out and looked under the starter battery and I'm pretty certain there's a heater under there. I see two black lines come up and out and a little clear line that I presume is fuel. I haven't really dug into it, but it looks like what everyone describes as the heater.

But I have no heater booster switch in the cab! I just bought this van nearly a year ago, so it might still have some features I don't know about. But why would I not have a switch.

Oh also the data card claims is has a heater booster as well. It also claims it has heated mirrors (which would be great if there was a button for that, too!)

Any ideas?
 

surlyoldbill

Well-known member
The booster switch is the bow-tie shaped center button just below the AC switch. The bottom of that round assembly should be the REST switch. This round assembly is just to the Right of the round vent/floor/dash selector switch.
 

brutimus

Member
The booster switch is the bow-tie shaped center button just below the AC switch. The bottom of that round assembly should be the REST switch. This round assembly is just to the Right of the round vent/floor/dash selector switch.
That's what I've read, but mine doesn't have that.

Here is some photographic evidence.
 

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NelsonSprinter

Former Nelson BC Sprinter
That is strange, a heater muffler and no switch. Is there a small LED light near the 9 o'clock position of the REST/AC,? if so press the left side of the center bowtie near 9 O'clock and see if it lights up. Someone may have rubbed off the symbol
 
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brutimus

Member
That is strange, a heater muffler and no switch. Is there a small LED light near the 9 o'clock position of the REST/AC,? if so press the left side of the center bowtie near 9 O'clock and see if it lights up
Nope. No light and no switch. I've pressed everything I can. I don't know the full history of the van, but perhaps someone replaced some switches at some point in the last 12 years?

The ghost of the phone number from two owners ago is still visible above the windshield, maybe I ought to call them. =)
 

surlyoldbill

Well-known member
I see the switch in your photo!

My led doesn't light up, either, but the espar comes on. It takes a minute or two. And the engine has to be running, and below operating temp.
A friend also has the espar, but her's doesn't come on (broke somehow).
 

220629

Well-known member
It is a Heater Booster. Has anyone mentioned that the engine needs to be running for the "bowtie" switch to enable both the heater and the red LED next to the switch?

:2cents: vic
 

brutimus

Member
I see the switch in your photo!

My led doesn't light up, either, but the espar comes on. It takes a minute or two. And the engine has to be running, and below operating temp.
A friend also has the espar, but her's doesn't come on (broke somehow).
Ha! I promise you, it doesn't move one bit. It's as rock solid as anything. Any photos of the espar switch I've seen, there's a little wavy bacon logo to the left of it. I don't have a logo, but after very close inspection with a headlamp, I can see a spot for an LED. Also, those logos appear to be painted on to a black surface with a clear plastic surface over it, so I doubt it's been able to fade or rub off. There's no sign of any residual paint where the wavy bacon logo ought to be.

I've jiggled it, rattle it, thumped on it, blown on it. Doesn't move. =( How hard is the dash to get apart, I want to look at it from the back side.

Also, thank you for the beautiful drawing. =)
 

surlyoldbill

Well-known member
come to think of it, mine does have bacon under a + sign.

Was your van a salvage title purchase?Maybe they replaced a bunch of stuff; OR, more likely, they were confused about the vent switch not rotating (needed to have cables lubed) and bought a used replacement from a van that DIDN't have espar. All three of those round switches/dials are mounted to the same circuit board.

I've had mine out enough to lube the cables, not hard but it takes a while. There are some hidden screws. Download the shop manual and it will give instructions for removal so you can see if there are some loose, taped-off wires back there. In the write-ups section there should be pictoral instructions on lubing the cables, which would show you how to get back there.
 

brutimus

Member
come to think of it, mine does have bacon under a + sign.

Was your van a salvage title purchase?Maybe they replaced a bunch of stuff; OR, more likely, they were confused about the vent switch not rotating (needed to have cables lubed) and bought a used replacement from a van that DIDN't have espar. All three of those round switches/dials are mounted to the same circuit board.

I've had mine out enough to lube the cables, not hard but it takes a while. There are some hidden screws. Download the shop manual and it will give instructions for removal so you can see if there are some loose, taped-off wires back there. In the write-ups section there should be pictoral instructions on lubing the cables, which would show you how to get back there.
Certainly not a salvage title. But to the other part, I can not speak. I've messaged the previous owner to see if he knows anything of it. This sound plausible, though. Maybe someone broke a knob and got a new unit. Maybe I can just hot wire in my own bacon button. I sure could have used a heater booster over the holiday -- while driving at -4F it was tough to keep the van warm.
 

Tooth Fairy

Away with the fairies.
I sure could have used a heater booster over the holiday -- while driving at -4F it was tough to keep the van warm.
The engines in these things sure dont get warm, at best they just take the chill off cabin air, Ive driven with a 12 blanket over my knees to stop the shivering.
My engine runs at 82 degrees c all day long hot or cold outside, the espar turns off as most do at 82c.

You also have to make sure you have at least 1/4+ tank of fuel for them to fire up, any less and they wont fire.
 

surlyoldbill

Well-known member
Vic will probably offer some wiring schematics. The thread in write-ups about wiring the espar to run with the engine off has all the schematics.
 

Speed Racer

2006 2500HC Passenger Van
Page 131 of the manual describes the heater booster, which helps the engine reach its normal operating temperature more quickly. When on, the indicator lamp on the bowtie switch lights up. Pushing at the 9 o'clock position of that bowtie switch turns it on/off. It's not a click on/click off switch, and it barely moves. A disconnected annunciator light could be misleading.

The little muffler is associated with the auxiliary heater (Page 134), which is operated either by a separate switch or a switch incorporated in the optional aux heater timer panel (like mine is). When on, my switch lights up and you can hear the diesel-fired, auxiliary heater unit fire up and the fan go on to push heated air through the cabin, regardless of whether the engine is on or not.

Looks like he has the the auxiliary heater but may be lacking the switch. Perhaps a previous owner took the timer unit out?
 
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220629

Well-known member
We're all guessing at this point.

My 2006 with aux control unit down near the shifter also has the frying bacon and switch for booster operation. In fact, the aux heater is controlled exactly like my 2004 Booster Heater when I'm frying bacon with the bowtie.

I think Bill may be on to something. The air duct supply rotation does have history of failure. Maybe the ATC module was replaced. :idunno:

The Espar muffler in the picture looks pristine. The heater probably hasn't been operated much or else I expect that the heat would have made that show some deterioration.

My DPDT switch pre-heat mod will get the heater to run. Or 12 volt enable power to pins #6 and #7 will test run it.

REST/Booster Engine Pre-heat with DPDT Switch Modification
https://sprinter-source.com/forums/showthread.php?t=36797


To give run control it would be little problem to use a switch fed from a "engine running D+" 12 volt source to feed pin #6 and #7 to enable the heater. I would not use a power always on or key on source for this enable switch mode for concerns about operating the heater while the engine is off without the aux electric coolant pump running. Operating the heater without coolant circulating will cause the Espar to overheat and kick out on the over-temperature control. That is not good for the heater.

vic
 
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autostaretx

Erratic Member
Looks like he has the the auxiliary heater but may be lacking the switch. Perhaps a previous owner took the timer unit out?
The 7=day timer was an extra optional gadget.

He has the "standard" little cubby hole piece/bin that MB puts in that hole (and he's filled with things in the bottom photo).

The usual three choices are:
(a) booster heater, bow-tie is only switch (although somewhere i read that cranking the controls to full defrost turned it on, too... but i can't re-find where i saw that)
(b) Aux heater.
(c) Aux heater with 7-day timer

If he gets his VJN-specific datacard from sailquik or a dealer, he'd know which the Sprinter was delivered with.

--dick
 

brutimus

Member
The 7=day timer was an extra optional gadget.

If he gets his VJN-specific datacard from sailquik or a dealer, he'd know which the Sprinter was delivered with.
I already have that as supplied by the PO. I'll attach that here in case anyone wants to take a look-see. I think I mentioned in my first post, it does show an entry for HEATER BOOSTER.

I'm still thinking the most plausible scenario here is the control unit got swapped out at some point. As vic mentioned, the muffler looks spotless.

Think there's any danger in firing one of these up after sitting unused for anywhere from 4-12 years? =)
 

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autostaretx

Erratic Member
From your datacard you just have the "booster" arrangement.

So: it will only operate when the engine is running
The bow-tie switch is (supposed to be) "it".
Since it requires the engine (with its belt-driven water pump) to be running for operation, i really don't know if it entails or requires a separate electric circulation pump. (the REST function does)

Here's the owner's manual's single page on it:

BoostHeatPage.jpg

--dick
 
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brutimus

Member
Page 131 of the manual describes the heater booster, which helps the engine reach its normal operating temperature more quickly. When on, the indicator lamp on the bowtie switch lights up. Pushing at the 9 o'clock position of that bowtie switch turns it on/off. It's not a click on/click off switch, and it barely moves. A disconnected annunciator light could be misleading.

The little muffler is associated with the auxiliary heater (Page 134), which is operated either by a separate switch or a switch incorporated in the optional aux heater timer panel (like mine is). When on, my switch lights up and you can hear the diesel-fired, auxiliary heater unit fire up and the fan go on to push heated air through the cabin, regardless of whether the engine is on or not.

Looks like he has the the auxiliary heater but may be lacking the switch. Perhaps a previous owner took the timer unit out?
I'm having a tough time finding a service manual for a 2004, but I've found 2005 and 2006, which I think are pretty close.

Are you implying that the little muffler is only associated with the aux heater and NOT the heater booster? This doesn't seem correct to me. I found an illustration of the heater booster in the manual and it looks just like the box I found under my headlight. (attached image)

I've yet to find much info on the aux heater and what any of the components look like.

The manual did have a diagram showing a switch for the aux heater would to the right of the steering column. I also do not have this switch. It has the factory plug covering this hole.
 

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