Complete loss of electrical power mid-corner
 

Hi folks. This past weekend my teammates and I were racing our 280zx in a 24 Hours of Lemons race and doing pretty darned well with less than 1.5 hours to go (25th place out of 196 cars.) The car is an absolute workhorse and had not missed a beat all weekend until we had a complete loss of drive and all electrical power mid-corner. The car was towed in and we spent the next hour trying to pinpoint the problem to no avail.

We checked the battery (and tried a spare also) and this is not the issue. The voltage gauge on the dash shows 13v+ so there appears to be 12v constant, but there is zero 12v switched. When we turn the key, absolutely nothing happens, no sounds, no lights on the dash, absolutely nothing. Because we had spares I swapped the alternator, ignition module, and starter, and not surprisingly these did nothing either. I checked all the fuses down by the passenger footwell and could see none that were obviously blown. We did not have a spare ECU so I couldn't test if this was the issue. It seems as though we are just getting no connectivity between the ignition switch and the next link in the chain.

Unfortunately the car is not at my house, so I can't do a quick "check this and report back" so what I'm hoping to do, with your help, is compile a list of things I should check to track down the source and then I'll do them all in one fell swoop and report back.

Thanks in advance for your input, we are excited to get the car back up and running to carry the Z flag and take another stab at success to

Check fusible links by the battery.

Also, is the battery securely tied down? I mean "SECURELY". If the battery can move at all, on a track it can flop around, increasing the chance of +12v wires grounding out. And make sure the alternator + pole is covered / protected.

Thanks NismoPick. Yes, the battery is pretty much solid as a rock. Again, we are getting some power from the battery, just not switched power, only those things taking constant 12v. By the fusible links, are you referring to the connections that are in the black plastic box, mounted on the inner fender perhaps 8 inches in front of the battery? I can see spade connectors going in one side and coming out the other side, but couldn't see obvious fuses in between. Are there fuses in there that I didn't see?

Yes, they are under the small rectangular black box by the battery. There are 4 or 5 of them supplying power to all electrical systems in the car. They are wires that burn above specified load capacity.

Click: XenonS130 - S130 Reference (download the FSM).
Click: http://www.atlanticz.ca/zclub/techtips/fusiblelinks/ (S30 links... but same basic setup)