Sharan Mk1 Booster Heater

[viking]

Ok, I know there is a lot of info on the booster heater but nothing covers my issue. My MK 1 Sharan TDI has the D3W Z Erberspacher unit. According to sources from this forum, the booster heater resets itself after the ignition is switched off, unlike the later MK 2. Therefore any lock outs clear themselves. My heater will not fire up at all. I unbolted the heater and tested from the pin outs using the test procedure from the Ford TIS. Blower motor, glowplug, flame monitoring sensor and overheating sensor all test ok using a multimeter. I unplugged the outside temperature sensor mounted on the wiper linkage support and bridged the contacts, started the engine, after a few minutes- nothing. I believe the blower should kick in after about 40 seconds. I believe the contacts for the outside temperature sensor are the main switch for the booster and should have 12 volts on one side. I get about 2 volts. Can anyone verify this. I tested with engine running, One lead of multimeter connected to earth, the positive lead to one side of the contact. Has anyone got a wiring diagram for the Sharan MK1. I have the Haines book for the Galaxy but the wiring/ fuses differ.

[chrispb123456]

Hi there

 

You don't say what year your mk1 is? if it's a late one then you could use the mk2 pinpoint test not the component test as you have done.

2 volts is wrong at the thermo switch should be battery voltage so would say there's a supply fault.

 

Also check out those thin wires on the battery terminals for corrosion/breaking

[viking]

Sharan MK 1 early 1997. Done some more digging around and found a D3W Z Erberspacher wiring diagram. You are right, the thermo switch should have 12 volts which should be presented to pin 6 on the multi plug at the heater. Tomorrow I'll do a test and stick a 12 volt supply to one side of the thermo switch connector. My next question is why no 12 volts... The Ford TIS Galaxy wiring diagram show fuse 14 feeding the thermo switch. Different on the Sharan. I checked all the fuses that I could see but all look ok. There must be a fues hiding somewhere ! Battery terminal wires all intact and corrosion free.

[chrispb123456]

agree stick 12 volts down the output of the thermo switch, will check the fuse numbers when I can get on my laptop lol

I have a VAG disc as well as TIS, there are usually two fuses for the heater one 25amp and one 5amp will let you know.

[viking]

Thanks.... I also checked the owners handbook which lists the fuses including additional fuses above the relays, none of which mention aux/ booster heater. I'll do the 12 volt test Sunday and update the post...

[chrispb123456]

Right the VW disc has fuse 23, 30amp as the main supply then fuse 14,15amp supply to thermo switch

 

In the TIS for the same year fuse 33, 30amp and fuse 14, 15amp

 

There are known mistakes in the ford handbooks and the TIS manual

 

Check the voltage at the fuse box fuse 14 depending on your spec other items also on this fuse, is there anything else not working.

[viking]

That's great, much appreciated..... everything else working ok but will do further checking and testing tomorrow... updates to follow.

[viking]

Right... fuse 14 is ok, also serves reversing lights and electric sun roof. Re-tested at Thermo contacts and seeing battery voltage. Very odd... couldn't have been getting a good contact with my test probs yesterday. Not happy, would have been nice an easy. Anyway, bridged the contacts with engine running.... no activity on the booster. The fuse box is numbered 1 to 22. Relays are above and further up are the auxillery fuses un numbered. Just one rated at 30 amps which I assume is Fuse 23 and that's ok. Only thing to do now is to unbolt the booster heater again for further investigation checking both voltage feeds via f14 and f23. Should appear at the Booster connector pins 1 and 6 and take it from there..... will have to wait for a nice dry/ warm day unlike today !! . I suppose the sealed ecu within the Booster can fail... I'll find out and update the post.. not sure when though ! Thanks for your help Chris. Edited November 4, 2012 by viking

[chrispb123456]

I can tell you in my experience with these heaters the glow plug is the most common failure part, the ecu on the D3 & D5WZ is pretty reliable.

I have only checked/replaced glowplug with heater stripped down.

One thing I will say is if that heater is still the original and not been apart before you may have a problem removing the screws securing the heater ecu and top covers.

 

Good luck.

[viking]

Update.... unbolted the booster heater for more testing. Correct voltages seen on multiplug terminals 1 and 6 and earth ok on pin 2. Retested components on the multiplug going in to heater, all looking good. Only thing not looked at was the 12 volt diesel metering pump. Sure enough, open circuit on pins 3 and 4. I checked the pump and found both spade terminals had become detached due to corrosion. Removed the pump, cleaned it up and managed to solder wires to the remains of the spade terninals. After satisfying myself that the joints were mechanicaly sound and conducting ok with no leakage to the pump body, I encased the terminals first in epoxy resin finished of with chemical metal and then a lick of hammerite paint. Stuck it back on the car ready for test. Bridged the Thermo sensor terminals and started the car. The familier sound of the jet engine and time bomb tick (from the pump) was music to my ears. The car is 15 years old with 166K on the clock and this has been the first time the Booster heater has failed. I first assumed it was glow plug failure even though it tested ok. I removed it for inspection and was surprised to find it looking like new ! The best bit is that the repair didn't cost a penny... not counting my time of course.

 

See pics of the repaired pump :

[chrispb123456]

Blimey mate your sure getting your monies worth out of that dosing pump :16: and still on the original glow plug that's amazing.

Well done :16:

[gregers]

:16: today a booster heater,tomorrow the WORLD :16: :22: Edited November 12, 2012 by gregers