C-3, Starter harness

[D S.]

1970 LS-5 with A/C
My A/C fan blower was working erratically so today I jumped right on it. The fan switch is new. I found a #8 or #10 yellow wire in the engine compartment that runs from the left firewall grommet to the right side to the fan blower that seemed to be the source of the problem as when I jiggled it the fan motor would react to it. My mechanic wanted me to remove the four wires and battery cable off the starter to look at those, too. As I was removing the nuts from the starter I looked up to see that the harness was resting against the right rear exhaust manifold and was clearly burned. One #10 black wire was severed, two #12s were lightly melted together, one other #12 purple had exposed wires but still intact. There was also a mystery wire or wires---two brown-white #14s single strand wire that had no visible connectors and both were looped twice in the original harness as if there was too much wire when installed. But they didn't seem to go anywhere but back to themselves. They were melted together in the damaged area. So, I simply connected the one brown-white wire to itself. After I patched the exposed wires and attached them to the starter the fan motor no longer works at all. The circuit tester showed 'hot' to the fan switch, fan blower, to the fuses, and to the relays. All ground wires are accounted for. The car does start and run as it did before. I am now pouring over the electrical schematics in the repair manual and my assembly manual. Can anyone tell me what the brown-white wires are and where they are supposed to go and what they are to activate? Neither the assembly manual nor repair manual shows this brown-white wire being in the starter harness.

Thanks,
Scott

[Guisseppe]

Re: C-3, Starter harness

From color wiring diagram the brown and white wire run from tha alternator to a "common connection" or "junction block". To identify it, the "common connection" or "junction block" has the following wires connected:

1. black wire from horn relay
2. 2 light green wires from frontal four headlights
3. red wire from horn relay
4. light blue and dark blue wires from directional signals
5. Brown wire from frontal marker lights and parking lights
6. Tracer red wire from ignition coil. Check that ignition coil is also connected with a tracer red wire to the start.

My recommendation is that you need to connect the brown & white wire run from the alternator to the common connection as described. Also, you must check your ignition coil and starter wires installation.

Please review your installation and let me know.

[Guisseppe]

Re: C-3, Starter harness

Correction:

Point 6 must read:

6. Tracer red wire from ignition coil. Check that ignition coil is also connected with a tracer red wire to the starter.

[D S.]

Re: C-3, Starter harness

Thanks for your help. The wiring diagram and related circuit numbers only show four applications for the brown-white wire and the schematic specifically identifies it with the alternator. So, I am thinking that there was an abundance of this wire to the point that it was double looped before being black taped into the harness bundle. It may have to do with OHM output. This week I am going to test the brown-white wire for continuity on both sides before rewrapping the starter harness. All else seems to be working okay....gauges, starting the car, the ammeter is charging, etc. Just the fan blower motor isn't so that may be a relay or ground wire issue. Or motor issue.