When i did mine, it's less than 18" of wire, and i'll only draw 150 amps very rarely, if ever, so i used 2AWG wire with copper lugs crimped on the ends. No issues in a year.
I had a similar issue, On mine i had a small crack where the heater core meets the outlet pipe. I replaced the heater core with another one (used) that was starting to develop the same problem, but i sweated the joint with some additional solder before installing it, seems to be holding up...
The heater valve and associated piping are not really necessary, if you ran a length of hose from the PHH port all the way up to the heater core, that would elminate 4-5 connections.
o2 sensors are just more out of the way and drier in that location.
remove the VSV's for egr and pair +...
Delete all the heater valve stuff up on the firewall
PHH -> one hose up to heater core
(sounds like 93-94) move O2 sensor to pair ports
Vacuum system cleanup after pair and egr
Security system delete
Factory radio amp delete (assume aftermarket radio installed)
OBD1 '94, but I removed the egr, vsv's, and plugged the holes in the intake when i did the head gasket. Shorted the harness wires together and no codes. Feels like there is so much more room now.
I wanted to update this thread as a lot has changed since it was written as far as replacing bulbs in the stock housing is concerned. Older HIR models have undergone some changes and are now available with the same bulb shape as 9005/9006 bulbs. The current 9011 and 9012 replacement bulbs are...
Check that the e-brake components are lubricated in the proper spots, and everything is tensioned correctly. just solved a similar noise in my 100 that way.