I have an intermittent ASF associated with the compressor relay R1 in the engine compartment fuse box. It is not related to the wiring, grounds, contacts or the relay itself (new). I noticed there appears to be a PCB inside of the fuse box, and I can easily see this being a bad solder joint on the relay contact.

Has anyone ever had one of the fuse boxes apart? I know the FSM says there are several "non serviceable" relays inside (laughable, few things are not serviceable!). That tells me there must be some kind of PCB inside.

I have searched around, but not found anything related to this. If I'm the first to pull one apart I'll be sure to post pictures.

Thanks,
-Michael

 

When I attended NP04 (new product 2004) we were advised that many of the external 'plug-in' relays were being eliminated and installed inside fuse/relay boxes and were considered 'non-serviceable'.

If a failure occurred then the box was to be replaced as a unit.

It's your car so you can disassemble if you want (I would if it were MINE) but we just replaced them at the dealer.

bob gauff

 

I have recently had to replace the fusebox in my boot due to a fault in the PCB, I have not attempted to take it apart though as I sourced a cheap second hand replacement so just replaced it.

 

Hi Mike

Thanks for the Molecular Sieve which my son Nick has recieved but he is calling it an "unknown white powder" which he will not take on an
areoplane.

He is "taking the Mick" (I hope)!

WRT a fuse box I have an used spare which I have partially dismantled

and I can tell you it consists of two pcb's about 1cm apart and the two

are joined around the circumference by about ?80-90 soldered joints.

Hence best bet is to obtain an used spare IMO.

Cheers

Bob

 

Any chance you could share a photo of the PCB?

Haha, glad the molecular sieve got there, hopefully works well for him. My pump is working better than new thanks to Andy's parts, now I'm dealing with an intermittent pump relay fault. It's symptomatic of a bad solder joint, and if I fiddle with R1 it'll work for a while, so I assume whatever is bonding the relay socket contacts to the PCB is having an issue.

I have had it running fine now for 4 days (knock on wood) after bending the contacts on the relay slightly. I may just source a replacement fuse box if they're easy enough to find. Then I can swap it out and dismantle the old one without fear of disabling the car...

 

I did have a photo of the edge of the pcb's but must have deleted it however I have drawn a little diagram which may help.

 

Thanks! Once the fuse box is out, I assume the disassembly is obvious? Looks like the inner plastic pieces un-snaps and then the PCBs pull out?

So far my relay issue has not returned, but I'm not expecting the "bend the pins" method to be a lasting repair.

Looked around eBay some yesterday... spending US$200 for a second-hand fusebox from a car older than mine is not going to happen. Will pull my own box out and fix it if the issue returns.

 

I decided to dismantle my fuse box again for some photos.

Bear in mind that this is the rear fuse box and has a screw on connection underneath, for a thick cable, which has to be released before the pcb's will come out.

Remove all fuses and relays and then un snap grey plastic top.

Pull out pcb's.

NB my drawing was wrong-the soldering is on the inside!

Photos to follow

cheers

 

Upper pcb and side view of both.

 

Side view of pcb's showing position of solder.Good luck with repairs!

 

Thank you so much meirion! That is a big help!

So far I've still not had a repeat of the ASF. If I pull my front box I'll take photos of the repair to share as well.

 

Has anyone successfully addressed dealing with the 2 circuit board in the relay fuse box.
Has tried to desolder or cut all those pins/wires connecting the 2 boards ?????

If I could only separate the 2 circuit boards aI could fix my relay without paying for a whole new fuse relay box !

 

I would buy an used one. Breakers these days will gaurantee their parts as

working and cars are scrapped just because o f a bump.

 

I had to replace my engine compartment fuse box because one of the soldered relays failed. Here is the thread:

https://www.jaguarforums.com/forum/x...ssages-132586/

Unless you have some ninja soldering skills, I just don't think servicing these things is option. Believe me, I tried to figure out how, but the way these are manufactured it's clear that there is a sequence to each solder joint from 1 to 1000, and you'd have to de-solder tens or hundreds of joints to get the culprit. Then redo them in sequence.

 

Easiest this seems to be to get a used one.

If you are really determined you can cut all the solder joints, then separate the two boards. Removing the relay would be PITA as well since you have to heat all contacts at the same time and there seems to be a lot of thermal mass to dissipate the heat.