Hella H1/H4 problem

[G-Man]

I flunked VA state inspection on my 91 318i due to my drivers side high beam being inop. I have a set of Cibie H1/H4 lights mounted in headlight buckets which I've swapped out with the Hella's and it still blows the #1 fuse. I've upgraded the fuses from 7.5 to 15 amp and running 55/60w bulbs in both my Hella and Cibie H4 lights and standard 55w bulbs in my H1 lights. I've replaced the headlight switch with a new one and the fuse still blows. If I spread the plug in connection wires, sometimes it will not blow for a day or two. Any idea's of what the problem is, bad ground, turn signal stalk, bad plug in connector, etc...? I have a spare turn signal stalk in my parts bin that I could swap out. I just wanted to check with the forum before I start pulling the steering column apart. I hate electrical problems.

G-Man

[Das Delfin]

You're saying if you spread out the wires, sometimes it will stay good for longer. Since a fuse will blow when current is increased, it sounds like theres something funky going on in the wires. Almost like there's a slight break and current is arcing across, creating a surge, which would increase the amperage and pop a fuse. It'd start by cleaning your ground at the headlight. The bulk of the current is going to be between the headlight relay and the headlight, so I'd start there before going into the dash.

[AndrewBird]

DO NOT PUT LARGER FUSES IN!!!

The fuses are sized to the wire size in the circuit. If you put larger fuses in, you will start burning up wiring before the fuse will blow.

It sounds like you have a short somewhere. start at the headlight plug and trace it back until you find it.

[DesktopDave]

Definitely sounds like a high resistance problem in the harness somewhere. I'd suspect the grounding bolt. All four headlights are grounded to one bolt behind the driver's headlight unit.

I've also had headlight plugs physically wear out. Contact prongs break, or they melt internally and tend to pop fuses. Those H4 replacement plugs aren't expensive - NAPA should have a decent high temperature headlight socket repair set like this for less than $30. I'd definitely be particular about splicing these into the harness though. I'd do a soldered lineman's splice covered with heat shrink tube.

If it's not that, I'd be tempted to swap out the relays (K3 & K4) with known good units before pulling the turn signal switch out. Also get a flashlight and look down into the fuse box for melted/broken terminal connectors on the relays and the fuses. Given that you have a '91 318i , you shouldn't have to worry about the low beam check relay of the spiffier M20 models.

[G-Man]

I unbolted the headlight ground and took a wire brush to the ground. Reinstalled the ground and everything seems to be working fine. Thanks for the input, I'll keep my fingers crossed and hopefully everything will be working on Mon when I get the car reinspected.

G-Man

[Das Delfin]

Well? How'd it go?

[G-Man]

Passed inspection, I'm good to go for another year.