Member Since: 22 Jan 2023
Location: Essex
Posts: 16
FBH short circuit faults
Hi guys, I am appealing to those FBH warriors out there. Having spent the last 2 weeks revising on potential reasons why my FBH isn’t running I bought all the necessary wires and plugs and have run a diagnostic, revealing 3 faults that I am hoping someone can provide some advice on. Combustion air fan short circuit, metering pump short circuit and circulating pump short circuit. The fuse is fine and obviously the thing won’t start even after clearing the faults. Other that stripping the unit down and cleaning it should I be looking anywhere else? I can’t see any obvious issues with the loom, although it disappears very quickly into the engine.
Last edited by Fin-M on 22nd Jan 2023 12:40 pm. Edited 1 time in total
22nd Jan 2023 12:38 pm
Fin-M
Member Since: 22 Jan 2023
Location: Essex
Posts: 16
22nd Jan 2023 12:40 pm
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1820
Hi, welcome.
A lot of willing help here, but generally it is greatly appreciated if you do a (small) intro and say hello before asking directly for help…..
Regarding your issue, all those components are connected to the Webasto ECU/circuit board on the heater itself… behind the big long plastic black cover..
Look for water ingress in the plugs and/or corrosion on/at the circuit board…Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
22nd Jan 2023 1:52 pm
Fin-M
Member Since: 22 Jan 2023
Location: Essex
Posts: 16
Thanks for that, I am assuming this is behind where all the plugs are and the exhaust etc. I pulled the top 3 plugs and they all look fine so I guess I will need to remove the unit and do a service and hope my control board isn’t fried.
22nd Jan 2023 3:33 pm
Fin-M
Member Since: 22 Jan 2023
Location: Essex
Posts: 16
As a precautionary move before I whip the FBH out assuming it’s the control board that’s knackered, I was looking to see if I can buy a replacement circuit board. That’s not such a cost effective option but I am seeing discovery 3 FBH’s on eBay from £50. The thought being that at the very least I could swap the circuit board over if mine is toast, but I’m seeing different part numbers on whole units and suggestions I should change like for like? There is a JEC code and a Webasto code. For £175 I can buy a “refurbished” unit but hey, it’s eBay after all, and the JEC code is different. Any one had issues with swapping FBH’s?
24th Jan 2023 8:56 pm
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1820
In case of the control unit, forget Webasto numbering/code
Webasto produces but with JLR specific firmware and connections…
So look for equivalent JLR numbering/partnumbers…
Basically any Land Rover numbered TT-V (complete unit!) between 2004-2008
Should work plug&play (if the unit itself is 100% functional)
Later LR TT evo/vevo might work, but also might not because of different firmware/can-bus speed etc..
I tend to believe that “all” 50 quid units on ebay are leftovers after exchanging the unit…
Well known salvage company should be able to supply unit’s which are at least not “ left overs after repair”
So maybe usable for your control board transplant….
Note it IS possible that during the lifespan of the D3 TT-V both units WITH fuel pre-heating and units WITHOUT fuel pre-heating were used, if so (i am not sure) the control unit will be differently between them and therefore NOT exchangeableBest regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
24th Jan 2023 9:58 pm
Fin-M
Member Since: 22 Jan 2023
Location: Essex
Posts: 16
Ah ok, thank you (I know my late 2006 identifies as as a 2007 model) I have ordered a service kit (the gaskets) and will source a second unit for spares but I would be tempted to try the second unit first and see if I can get a different result on the software, and if it fires up then problem solved.
24th Jan 2023 10:10 pm
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1820
Since you have the webasto diagnostic software, read the code’s from the new to you unit first…
The software is ok for clearing code’s BUT do NOT tempt to prime fuel etc!
Priming is ONLY for/if fuel lines and or pump is exhanged..
NOT if only the unit is serviced or exchanged….Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
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