How to check chassis wire lume?

Hello
Just asking if anyone has any top tips on how to check the wiring lume in side the chassis, just welded a new A frame crossmember and now fuse keeps blowing. Any help much appreciated.

Its a Loom mate, you could use a multi meter and then disconnect each wire in turn and check the continuity but this would take some time.
If everything was working before then there is a good chance the welding has melted the loom.
I would just replace it from the plug in the engine bay to the junction in the rear corner.
You can pull the replacement through the chassis with the old loom section or run it external on top of the chassis rail.
A length of heavy duty trailer cable is good for this job.

I have just fitted a new Autosparks rear loom to my 90 while I replace the chassis.
The Autosparks loom is what you want but beware that they quote delivery times of up to 12-weeks and in my case it took 10-weeks to arrive and that was before COVID caused all the shutdowns.

Before spending lots of money do as mentioned above, pull the old loom out and inspect it as it probably possible to piece out the damaged section at minimal cost.
Make sure you attach a draw-wire first otherwise you will have to feed it back in.

I believe 90 and 110 both have the same length chassis loom (extre length of 90 one is folded up inside chassis) so if you have a 90 you might have enough slack to pull out one end or the other and get to the damaged bit?

Certainly Autosparks only sell one length of loom (different specs available but only one length) and yes, on my 90 I have the excess curled up inside the chassis.