Tcheairs38655

I know there is a thread here somewhere dealing with the application of 12v power to the fuse box without an engine installed in the car. I have seen it but cannot find that thread in a search.

I have just replaced all wiring harnesses, front end and dash. The dash cluster is now sitting on the 6" threaded bolts used for the rewiring with everything hooked up. I'd like to power up all systems and do a test run on all the switches, cluster illumination, headlights, horn, heater, radio etc before reinstalling the engine in the car. I have already tested all of the bulbs in the instrument cluster and otherwise. Seems to me I read somewhere there was a concern about powering up the ignition system without a coil, distributor and other components of the ignition system. There is no engine or any of those components installed in the car yet, however I do have the TI ignition amp box and (new TI harness) installed. The ends are not connected to anything obviously but taped off. But it would be nice to be able to check the presence of 12v power through the ignition switch to the starting system also.

What 12v battery connection could I safely make? And I assume the battery would have to be grounded to the frame. There is of course a hot lead which connects to the alternator to the external voltage regulator and there is a Bat and Accy spade terminal at the bottom right of the fuse block.

Suggestions and cautions would really be appreciated...

jim lockwood

I wouldn't use a 12V battery to ring out the harness.

I suggest you connect a low Amperage, dumb battery charger and probe the individual circuits with a test light. The advantage of a low Amperage charger is that it doesn't have enough oooomph (technical term) to fry a wire if there is a dead short. And you need a dumb charger which will source Voltage regardless of what it is or isn't connected to. "Smart" chargers have to see battery Voltage before they will turn themselves on Dumb chargers don't care.

Powershift

I am helping a friend restore his 1969 Corvette. We are currently installing the various wiring harnesses. My plan is first do a thorough visual checkout to make certain I have no loose wires that can short to ground. I would tape up the ends to prevent metal contact.

I am considering using a 6 volt lantern battery as the power source. It has low voltage and minimal power storage capacity. Then use 6 volt test bulb or my Fluke multimeter to check final connections and switch functions. A regular 12 volt bulb should also work, but would be very dim. I would not try to run blowers or wipers but would just check the power to that device. If all checked okay, then go to 12 volt to check these items.

FWIW.

Larry

Tcheairs38655

Thanks to both of you, but where would you connect the 6V or dumb charger?

Powershift

I would go negative (-) to chassis ground somewhere on the frame. For positive (+) I would connect to the large 10-12 gage red wire that attaches to the starter solenoid and runs to the horn relay and firewall connectors........which then go to the fuse box. I believe the wire color is red at the solenoid for 63-66 years, but for 67 it is a 14 gage brown fusible link and then the 10 gage red wire. The horn relay wires need to be fully connected, as it serves as a buss bar. Or........ I guess you could connect directly to the red wire at the horn relay that feeds the firewall connectors. But this then excludes the alternator output wire.

Larry

buns

More to come when I find them:

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