1990 Other Vauxhall Models Damp proofing?

Hello,

In the wintertime, my car suffers from immense condensation underneath the bonnet when left for more than a day. This causes the electrical system to ground and the car not to start.

This means every sunday, I have to wipe my ignition system dry and use damp start spray to get the engine running.

My question is, without covering the engine with a blanket when left, is there a way to stop this moisture building up such as maybe cutting a vent in the bonnet, or any other way?