webasto fbh pcb failure

[rover 75 ted]

I was chuffed to retro fit a fbh in my cdti tourer using the info on this forum, but after I got it going it was smoking so I did what was said and took it back off and cleaned it, then it would not work. I spent ages looking at it, I found the manual switch wiring had broken where I had soldered the resistors, so I rewired it using stronger automotive wire and used led lights that didn't need resistors , but it still wouldn't work, I took it back off and changed the glow plug, still didn't work. I got another unit and changed the pcb over and it worked for three weeks, then stopped. I have found that there is two fuse positions inside the car that are for the fbh but are wired up. I have also noticed that if you buy a fbh wiring loom it has three fuses and a relay on it. so is the problem that it needs the new loom put on, or is it something I've done. I would like to have a go at fixing the board myself but it looks far from easy, I have even found it very hard to even get the resistors identified properly. I took it to a repairer and he said that the biggest resistor that causes problems that has been identified on this site is a 4.99k which isn't the same as stated on the site. you also have to know the sizes and he told me they were size 1206 and 0805 and on the board I showed him there was also a couple of capacitors next to the resistors that have blown, you can see that but cant see any burning on the resistors. anyway if you don't know anything about electronics like me they might just as well be talking in Chinese. its annoying when you've seen it working and spent the time, I would appreciate any advice you may have, thank you for reading this and i'm not used to doing this so no doubt I have made mistakes.

thanks ted