FBH diagnostics
 

Hi all was wondering if someone could give me some help .I've been having some issues with my fbh . So I decided to investigate a little further and made a diagnostic loom similar to this one with the addition of a wire to pin 3.https://rover.ebay.com/rover/0/0/0?m...2F192411838077 along with a cable like this which I use for Toaf https://rover.ebay.com/rover/0/0/0?m...2F392399423116 however no matter what I seem to do I can't get the wabasto software to communicate with the fbh weather it be using the loom I've made directly attached to it or though the car using the obd port. Do you have any idea where I'm going wrong I've seen talk of using a 1ohm resistor but am unsure if this is my problem and if it is how to apply it .
Many thanks Matt

neither of your links seem to go to the appropriate item.

I would say the best thing is to fit the fbh to the car, plug it in and try to start it.
Depending on what happens a more accurate diagnoses can me made.

Can you measure the resistance of the glow plug? It needs to be 0.5 ohm or less
Can you test to see if the water pump works? I'm not sure it may be polarity conscious.

Check in the How to section, there may be guidance about possible faults if the FBH starts up and then dies.

The pcb's are a weak point and it is common'ish for them to fail

macafee2

Hi Matt
If you want to communicate with thermis test off the car you do need a 1ohm resistor on the k bus wire, when the switch opens it pulls the voltage up to 12v and when it is closed it pulls it down to 0v.
It needs to be a resistor so the switch can overcome the voltage otherwise when closed and connected to 12v it would blow the fuse