I am installing a repro underhood wiring harness in my 69 GS. I ordered the harness from American Autowire, and told them it would be going into a very low-option GS--no A/C, no power-anything. Anyway, there are 3 "extra" wires that I can't figure out where they should go. 2 come out of the harness by the alternator, and the other one exits the harness halfway to the starter. Since my engine has been modified, are these wires for idiot light sending units? (I am now using mechanical oil and temperature gauges). I checked wiring diagrams but they didn't help me on this particular issue. Do any of you know, from the wire's insulation colors and connector shapes, if I am on the right track in my guesses regarding these wires? Thanks. Here is a pic of the first 2 wires by the alternator:
Dark blue is oil pressure, dark green is water temp. (near alternator connectors) What color is the one near the starter?
The one halfway to the starter is the blue one, so I can see how it could connect to an oil pressure sending unit. The green one does make sense for water temp, so thanks for the help on that one too. The wire next to that green one is pink in color. I thought it might connect to a terminal on the alternator but that seems weird since other wires already go to the right places on the alt.
Pink is the coil wire from starter switch/resistance wire path. (and would be with the water sender wire by the alternator).
I was just gonna ask if the pink one might go to the coil. Thanks Michael! My original harness has been butchered over the years with extra wires cobbled together, (and the coil has been relocated to the other side of the engine) so I wasn't sure on some of the new harness. It will be nice to have things back to original.
You guys are lifesavers! Now I won't worry about blowing fusible links or starting my new $$ harness and engine on fire when I "fire" up the engine, which hasn't been started in years.
Fusible links are a good thing. I do not remember if my 68 had any, my 64 did not (and a broken alt burned some wires). Bruce Roe
GM started using fusible links in 1967. I install fuse-able links to ANY older cars that don't come with them from the factory originally. With a customers permission of course. I try to explain to them & what the positives are about them. Even add them to 6 volt cars. The explanation I give is "even if you have some-kind of electrical kill switch or a fire extinguisher by the time you realize there's an electrical short before you realize it your already in a panic" & by that time it may be already too late. IF the fusible link melts it may leave you stranded on the side of the road , BUT it's better than having your vehicle burn right before your eyes. Tom T.
Thanks for the additional info, guys. One more quick question: Does the 1969 OEM wiring harness contain a resistor to lower the voltage to the coil once the engine is running? Or do I need to add a ballast resistor to my new wiring? Thanks!
Yes, it has the resistance wire. It comes out of the bulkhead connector and runs with the white/orange/purple wire to the starter solenoid junction where the yellow wire to the solenoid is and the pink wire to the coil.
Excellent! Thank you. There is a ceramic resistor on the firewall that someone had installed a long time ago, and I didn't know whether I needed to use it not.