nodestination1

iTrader: (2)

I'm in the process of restoring a 1987 TII that is totally FUBAR. It had a microtech ECU at one point but the PO ripped it out and left the car for dead.
The wiring is a nightmare, but I'm slowly sorting through it. I got power to the BUSS fuses (horn and dome/courtesy lights aren't working, but we'll get to that later) but no power to IGN1 or IGN2 fuses. And obviously no power to the starter.

I took apart the column to get access to the ignition switch. It's getting power from the black wire like it's supposed to, but as soon as I turn the key I loose power to the ignition switch. At the same time I hear a relay click near the firewall. A couple times I delicately turned the key to the ACC position and I got power at the blue (ACC out) and black 12V. But once I turned to the on position I lost power again.

I had a spare ignition switch and switched them out just to make sure the switch wasn't junk. no change. The battery is fresh and rated at 700cca.

I also hotwired the various outputs to make sure they were functioning properly. I ran a wire from the + battery post to the IGN1 output on the ignition switch, and the windows and turn signals got power. Then I ran the same line to the starter solenoid and the car turns over.

Any ideas? What could sever power to the ignition switch once the key is turned to the on position? I do a lot of car diagnostics, but this one has left me scratching my head.

Also - There's a special place in hell for the kid that hacked up this RX7. I've found MANY wires that were cut, loosely twisted together and left uninsulated.

AGreen

iTrader: (11)

I had a similar issue to this one. I think the issue was that the connection at the 80A fusible link in the fuse block under the hood, there are 2 screws that hold the wires to it. Check the connections there, because they may be corroded or loose. If all else fails, run a new wire from that to the ignition switch.

You can do a voltage drop test too. Check the voltage across components. For instance, if a fuse is blown in a circuit, the voltage across that fuse should be 12 (full voltage). Likewise if a corroded connection is dropping voltage, it will read as some positive value.

satch

iTrader: (1)

You also have a Black plug which mates two cables where one Black cable comes from the Main fuse and the other cable comes from the ignition switch. If this connection is poor then you can lose power at the ignition switch. Plug is located about a foot below the engine fuse box.

nodestination1

iTrader: (2)

Cool, thanks guys! I decided to run a dedicated wire to the ignition switch and got the accessories and ign1/2 stuff to work. One weird thing, the fuel pump came on with they key turned to on. I think it's because the AFM is removed and the PO jumpered the fuel pump relay.
Car still won't turn over... but the single black/red wire gets power with key to start, so I'm running another direct wire from the ignition switch to the starter solenoid. There are loose wires everywhere, I'm trying to clean it up and tuck everything nicely. I swear this car is held together by zip ties. Next up is wiring the microtech to the coils... should be a fun day!

AGreen

iTrader: (11)

Man that really sucks about how hacked up your harness is. If I were you, I'd get all the accessory stuff working (e.g. headlights, wipers, turn signals, brake lights, dash, etc.) and then wire in an inexpensive standalone. That way you will at least have a known good engine management harness that won't give you headaches from chasing down bad splice jobs and more hacks.

satch

iTrader: (1)

The B/R starter wire from the ignition switch either runs to the interlock switch or runs directly to your starter cut relay. If your car is w/o the interlock switch (makes the driver depress the clutch to start the car for safety purposes), then the B/R wire runs to the starter cut relay. If the alarm has not been deactivated then the relay will prevent the car from starting thus possibly explaining why your engine will not turn over.

nodestination1

iTrader: (2)

Ya know... I was thinking about it today, and the car was on the lift when I was trouble shooting the ign. switch. I may not have been sitting in it and therefore didn't have my foot on the clutch... god that'd be embarrassing.
Agreen, that's exactly what I'm doing. I picked up a microtech LT10s and some factory coils for $650 that I'm almost done rewiring. I have good spark at the lead plugs, I still need to wire up the trailing coils. Then I'm going to try firing it up :P
Satch and AGreen, your answers were extremely helpful. Thanks a ton. I'm hoping to keep this thread open because I still have quite a few other electrical gremlins to track down. (no horn, wipers only work on intermittent 1, sunroof is stuck, etc.)

Here are the old coils... why use nuts and bolts to hold stuff together when you can just use a web of zip ties? lol

RotaryEvolution

iTrader: (30)

if it's really that bad you may consider running a new wire from the ignition, through the interlock switch and to the starter. the cut relay and rest of the system were/are problematic on these cars anyways with all the high resistance and "click click" issues the wiring presents now.