Firewall Bulkhead connector

I agree w/ Rusty. The factory only used a bulkhead connector for easier factory assembly. By the 1980's, I think most cars went to running wires straight thru a rubber seal. That was because they had many more wires then and more reliable. My 1985 M-B 300D is more unique, where the fuse box is installed in the firewall so also serves as a feed-thru. I don't know if other Euro cars did that. But, a mechanical diesel so not many engine bay wires and most controls are vacuum-operated.