Help with parking/diesel heater on XC70 - Ardic 912D

skruving · Post by **skruving** » 27 Jan 2023, 11:32

Hi there !

First post here

After having a "cold" car for almost a year, i finally sourced a used parking heater that fits on my car, installed it today, but no heat.
The pump starts, and the fan starts for a minute, on the display in the car i get a blinking "on" notification, but no exhaust from the unit itself, this is while the car is idling.
When the car is "off" and i try to manually start the unit i can hear the fan starting for 2 seconds while the dash blinks "on" a few times before it turns off again.

When i took out the old unit i expected some diesel to come from the diesel line, but it was completely dry.
My assumption is that it is not getting fuel.

Any suggestions on how to approuch this ?

hrs and hrs of googling have not made me much smarter, and i hope someone can point me in the right direction. would love to get this fixed to finally have some proper heat in the car again

2007 XC 70 summom diesel 185HP

Thank you

Post by **jonesg** » 28 Jan 2023, 06:19

we don't see diesel volvos here in the USA.
I see you posted over in the UK volvo forums, they'll know if anyone does.
Its saturday morning, they probably still have hangovers.

skruving · Post by **skruving** » 28 Jan 2023, 09:47

haha lol, good point, and yes id assume so. thank you friend.

Post by **jonesg** » 28 Jan 2023, 20:03

Well if you don't get any response , consider it like any other repair, its a fuel feed problem is all.
Where and how is the feed designed, does it have an external pump besides the engine fuel tank pump.

I looked around a bit, it does have a pump, located below the heater unit, remove headlight if you need to access.

Watch this, he's using launch x431 pro to read codes.
REad the comments below the video, they look like your native language...maybe.

Post by **jonesg** » 28 Jan 2023, 20:05

jonesg wrote: ↑28 Jan 2023, 20:03 Well if you don't get any response , consider it like any other repair, its a fuel feed problem is all.
Where and how is the feed designed, does it have an external pump besides the engine fuel tank pump.

I looked around a bit, it does have a pump, located below the heater unit, remove headlight if you need to access.

Watch this, he's using launch x431 pro to read codes.
REad the comments below the video, they look like your native language...maybe.
There are more videos too.

skruving · Post by **skruving** » 29 Jan 2023, 03:39

yea i´ve seen this one, this on an XC90, a bit different from the XC70 but not by much.
The pump on the heater unit is a circulation pump for the coolant, not for the diesel fuel.
I could not find any schematics of the fuel line for the Ardic 912D, so don´t know where the fuel comes from, in the video i hear a ticking sound which sounds like its the diesel pump running to give it fuel.

Thank you again

skruving · Post by **skruving** » 29 Jan 2023, 12:50

I dug some more and followed the fuel line back to where the diesel filter sits where i found the small pump i can only assume is meant to feed the diesel heater, when measuring if the pump gets a signal i read 0.03volt before trying to turn the heater unit on and 0.06v for a few seconds as the fan in the heater unit starts and then back to 0.03v.

i also tried giving the pump 12v from a separate source which made the pump go click once and then nothing more.

assuming that something is off with the pump, and maybe also the wiring to the pump? I checked all fuses in the car that could belong to this, and none are broken.

if anyone can confirm or point me in some direction much appreciated

Post by **volvolugnut** » 29 Jan 2023, 13:03

I knew nothing about the Ardic 912D heater, but decided to Google Ardic 912D Heater. There are several sources for repair kits which appear to include motor brushes. I did not investigate, but you may find useful information on google. It seems these heaters are used on other vehicles as well.
volvolugnut

skruving · Post by **skruving** » 29 Jan 2023, 14:10

yea, i have spent my fair share on the google already

it seems like anything that´s not available in the US is really poorly documented. so cudos to all you "over there" making all that good info available

Post by **volvolugnut** » 30 Jan 2023, 08:12

I looked at my Haynes V70/S80 manual for 2001 to May 2007. It has some information on diesel aux. heaters. The heater burns diesel fuel from a fuel pump to heat coolant for the engine and passenger cabin. The system includes fuel pump, coolant pump, glow plug, control module, piping, wiring, and thermostatic controls. There are overheat protection thermostat (square plug) and coolant temperature sensors (round plug) under a cover. I suspect the pumps may be powered by Pulse Width Modulated power signal instead of direct current. Both motor are shown in the basic schematic to be controlled by the combustion preheater control unit which is connected to the central electronic control unit.
volvolugnut