Webasto heater not working!

[Mr Soft]

I have a 1989 Westy & I am struggling to get my Webasto heater DBW-46 to work (-3 degrees isn't fun). I switch the heater on using the flame button, green light comes on. Switch the heater switches to position 1. Pump then sounds like it is working but fan under rear seat does not start. After approx. 60-90 seconds the green light goes off.

With the key in the ignition (and turned to the second position) the fan starts. So I guess it is not a fault with the fan?

Tried the Webasto heater after a 2 hour journey with no key in the ignition & it started up a dream, warm air & three fan speeds!

Am I missing something?

Can anyone help or advise of a service centre for these in the West Mids.

Thanks for reading.

Mr Soft

[jed the spread]

The fan works when the coolant is up to temperature. After a long drive it will be so works even though the webasto might not be firing up. Have a look to see if the lead to the glow plug is on properly or take the glow plug out and give it a clean with a wire brush. Before you do all this you should check the two fuses of course, i think one on the left is for the webasto fuel pump and fan and the one on the right is for the glowplug. This is assuming its like mine and fitted behind the rear light. I did this on mine about an hour ago look- https://club8090.co.uk/forum/viewtopic.php?f=2&t=49175" onclick="window.open(this.href);return false;

Its worth a try but i am no expert

jed

[T'Onion]

Could be the glow plug , take it out and have a look ,could be covered in carbon build up

With the engine running does the unit fire up

[Oldiebut goodie]

Extract from workshop manual:

Upon switch on positive control voltage is applied from the
battery across F2 and terminal A5 to the electronics of the
control unit.
- operating indicator light H1 illuminates.
- glowing is activated via relay K1 and circulation pump
via relay K2.
- after pre-glowing (approx. 30 sec) a cycled voltage is
applied to connector C2 via transistor V108. From
connector C2 dosing pump Y1 is triggered across
temperature fuse F3.
- the safety period of approx. 90 sec commences.
- after fuel priming time (approx. 5 sec) the combustion
air fan motor M1 is started in full load mode via relay
K4.
If there is a "flame" condition during the safety period,
flame sensor B1 signals "bright" and relay K1 deenergises.
The safety period is reset and the glow plug is
switched off. This procedure requires approx. 15 sec for
normal ignition.
Repeat start:
If there is a "no flame" condition during the safety period,
there will be an automatic restart attempt with a 30 sec
run-down involving glowing, pre-glowing (approx. 30 sec)
and safety period (approx. 90 sec). This start-up pattern is
also applicable for a re-activation during controlled
operation

PM me your email add if you want manuals for it.

[Mr Soft]

Oldie but goodie, you could be right, will check in the week, Thanks.

Where are the fuses for the heater, are they with the standard fuses near the steering wheel, or in the engine bay?

With the engine running I can hear the heater trying from the engine bay.

Thanks for your help so far

Mr Soft

[Oldiebut goodie]

Re-reading your 1st post it seems possible that your temperature sensor is slightly out of normal range and only working in range after the engine coolant has heated it up. I would suggest working through the fault-finding in the manual as it gives you the exact timings for the various error conditions.

[Mr Soft]

Have managed to download the manual from the interweb for nowt! So will look through it later & see what shoild be happening when. Will keep you posted.

Cheers guys!

[Oldiebut goodie]

I said Pm me your email and I could send you the manuals!
Have you got the workshop manual or just the installation one?