What Next With Non Work Aux Heater

[marinabrid]

hi had car checked, no faults logged with heater but still she wont fire up. got new glowplug in, is there a way to remove it and set it up on a test bench to see if it will work ? anyone done this ? there be power there and fuel but nothing else!

any ideas where to try next to get it working ? :lol:

[Guest vr6galaxy]

IIRC you can check it's operation via VAG COM :lol: have you tried tricking the unit into life by replaceing the temp sensor with fuse as suggested by others?

[Jeff115]

Hi Martin,

Check the voltage at the pins of the 8-pin multiplug located at top of booster heater, with the ambient temperature sensor bypassed and with engine running:

 

if you hold the multi-plug connector with the flat side to your left and the rounded side to your right and

pins 2, 4, 6 and 8 are across the top row from left of the multiplug (8 is blank)

pins 1, 3, 5 and 7 are across the bottom row from the left of the multiplug (5 is blank)

 

Start signals required by booster heater:

check pin 1 - terminal 30 voltage from the fuse box

check pin 7- terminal L is from the alternator, voltage if engine running

check pin 2 - terminal 31, temperature at coolant temperature sensor is less than 75 degrees

check pin 6 - indicating that temperature at ambient temperature sensor is less than 10 degrees or that switch is bypassed

 

You can also check the operation (and without the booster heater running) of the combustion air blower and the fuel metering pump using VAG-COM

Hope that this helps,

Jeff.

 

Also I see from your other post that you had corrosion issues, seized bolts etc. - I'm not sure if the booster heater is earthed through the body to the car frame but you should check that you have good earth now also.