Hi guys,

Trying to troubleshoot two issues.
1.) Cooling system
Just removed the old Thermostat cap while cleaning the engine bay, and then I went for a drive last week. Noticed some leakage on the thermostat, so I replaced it with a new part from Moss.
This weekend, I go for a drive, and the cooling system "pops" mspraying coolant everywhere. The explosion of water seems to have come from the (non-pressurised??) thermostat cap, but maybe from elsewhere. Coolant was everywhere. I will have to invest in a pressure tester I guess (Harbor freight ok?)
2.) Electrics, manual overdrive unit slowly stopped working, and I believe it's an electrical issue. This is a manual conversion car, do I need to add a separate fuse under the steering column? It keeps blowing the #4 35a fuse over and over. How to test?
Also, number 5 fuse (horn relay, map light) is blowing. Any common shorts I can look for on either circuit?

Thanks, Ian

 

Update: problem with cooling system is definitely the new header tank cap from XKs. (non-pressurized cap).