Usain_Boat

Tested with it dead, the coil has 12.8 volts as to be expected with the engine not running. Testing from anywhere on the circuit that provides power to the flasher fuse, even at the fusible link that protects the fuel pump power as well as to the ignition relay to be switched into the White/black wire gives a reading of mV to ground and the battery. With it dead unplugging the reverse lights and plugging them back in turns the car back on and while doing this I noticed the right hand reverse light is much more dim than the left hand light.

Well I've already traced power for those circuits. I lose power at the fuel pump relay output (the relay clicks off) and I also know I lose power on the wire that provides power to the solenoids in the fuel pump control relay and fuel pump relay. I think a big clue is this is the same wire that provides power through the flasher fuse to reverse and turn signals. Though I blow no fuses! So I'm not sure. If I'm not blowing the flasher fuse or the fusible link for that circuit, should I be looking ahead of the fusible blink at the white wire that powers the fusible link? If I pull the flasher fuse the car doesn't die either, though it not blowing that 10A fuse is confusing.

Engine still died with the ignition relay bypassed.

Ok, I will keep testing with the ignition relay completely bypassed.

So when I was testing while the car was dead, the relay had continuity across the contacts from the White/Red from the fusible link to the White/Black. Therefor the relay was working as intended I believe. The problem is that 60 mV on the circuit is not going to be enough to energize the fuel pump control or fuel pump relays that are on that wire. Also, the reverse lights are not on either since there is not enough voltage to run them. Through all of this the car will die once but as soon as you shift out of reverse and restart the car it won't do it again for a while.

I took apart and cleaned the hazard switch recently to get the turn signals work so what should I look for wrong there? The power from the ignition switch to the ignition relay doesn't die, the Black/White wire at the relay still has 12.8 volts so that should have the coil energized and the relay still on. The problem is the voltage on the circuit that provides power to the flasher fuse, fuel pump control relay, and fuel pump relay loses power. This is the White/Black wire when it leaves the ignition relay. The Black/White wire that comes from the ignition switch has power at the relay, I'm not sure if it loses power in a shutdown event. I haven't tested anything else to be dead but next time I will test the wipers and blower.

Just opened the ignition relay as best I could and Its not rusty inside, the ground is still attached and I would rather not break it so I wasn't able to open it all the way.

Well I went with a hunch and built a new ignition relay out of two 40 amp SPST relays like @SteveJ (I believe) outlined on zcar.com and it still dies in reverse. I took the readings aforementioned by sticking the probes in the back of the connectors while it was dead so I could keep it in the state that kills the car. It is possible they aren't the best readings. If I was to take them again, what would be the best way?

So I got the car to die this morning and just tried to follow the power back. The Ignition relay is still on but i have like 60mV across the whole line even back to its fusible link. I decided to follow most of the circuit and take resistance measurements which are as follows. Fusible link to ignition relay: 0 Ohms Across ignition relay: 0 Ohms Ignition relay to fuse block: 5 Ohms to the fuse and 7 Ohms to the green wire side of the flasher fuse. Ignition relay to C4: 0 Ohms Ignition relay to fuel pump control relay: 4.5 Ohms Fuel pump relay to Fuel pump control relay: .1 Ohms To be clear, this is following the White/Red wire from the fusible link to the ignition relay where it leaves as a White/Black wire. Another observation I made through this process was the ignition relay got noticeably warm while there was 60mV on the circuits above. Could my ignition relay have an internal short that is causing this? Because if I understand the ignition relay shouldn't have enough resistance to get hot. I also checked for power from the Black/White wire from the ignition switch and it is showing 12.8 V so the ignition relay should definitely be on.

The reverse lights only turn on when the trans is in reverse and the car doesn't turn itself if in reverse with the switch unplugged. However even with this done, the turn signals still turn it off (confirmed the left does it not sure on right). And just to confirm, I'm talking about the white and black from the ignition relay that provides power to the control relay and not the one that turns on the fuel pump relay itself.

So I have my fusible links set up like @Captain Obvious black in the front outside and red in all the other positions.

Ok, so the forward most inside fusible link block is shown to run to the bus bar that feeds the flasher fuse on the fuse block. Its actually on the rear block if i remember correctly. I'm using the 78 color wiring diagram.

Yeah It wasn't necessary, on further testing it does nothing and the car still dies. I have found out that the Fuel pump control relay loses power on the white/black stripe wire when the car dies in revere and the power is returned as soon as it is taken out of gear. So, as @SteveJ has suggested, something is probably causing a MAJOR voltage drop when the turn signals or reverse come on. Or, they are somehow turning off the ignition relay.

Yes it's one with a two prong "T" connector. Not the 240/260 one. It's just an import direct one from O'Reilly.

So I bypassed the fuel cutoff from the oil pressure sending unit today and that may have fixed the issue. I know this is a terrible solution and don't plan to do it more than for testing so the next question is what would be a good recommended oil pressure sending unit to replace the Chinese one on it now? To specify, I bypassed the fuel cutoff in the oil pressure sending unit

I have physically traced the entire reverse circuit and have found nothing obviously wrong. It was a wire that had been exposed earlier but I have already cut that section out and reconnected it with a weatherproof crimp. So now I'm suspecting the reverse switch itself to have a problem. It might should have been checked earlier since I did just replace it when trying to get reverse lights working...

The splices were already done by the PO, I just replaced the crimps. I didn't check that they went to the correct places though I did notice Saturday that the front and rear blocks are wrong in the wiring diagram for 78.

This evening I disconnected the reverse switch to isolate that and it died with the left turn signal. I could hear the ignition relay clicking on and off with the blinkers. At this point I know of two instances where the left turn signal has killed the car not sure on the right turn signal.

Took a look at the rear of the harness this morning and I don't see anything suspicious. The place where the electrical tape is where it was already peeling off so I peeled it back further to look. Attached are pictures

Also the problem is very intermittent and doesn't want to happen right now so I'll have to wait for it to act back up.

I've gone through them and it is 10A that's part of what's baffling me.

Daily update: took apart every connector I could find that might be part of the problem and cleaned them very well including the leads for all the relays, the fusible link terminals and other things. After doing this I plugged everything up fired it up and shifted into reverse which killed it again Though this time, I could shift in and out of reverse and hear some relay (wasn't able to track it down) click on and off while the dash lights (batter charge and brake indicator) turned on and off with shifting into reverse. After about 10 times the car quit doing it so I was not able to test anymore.

How powerful of a soldering iron do you have? Using a 15w one I was struggling with 14 gauge

Digging deeper I do remember some splices in for the connections to the fusible link that I thought I fixed from the PO. When I got the car there were heat shrink crimps where the plastic was cracked and gone so I took them off and redid them. The fusible link in question (I believe it's the one closest to the engine in the front) has some green corrosion within the crimp and I also didn't get all the strands into the crimp. If I was to cut all of this out and redo it what gauge wire should it be? It looks heavier than the 14 gauge I have and is getting pretty short from whatever the PO did.

If I'm reading the wiring diagram correctly, the white with black stripe wire that turns on the fuel pump relay is the same that supplies power to the flasher fuse and fuel gauge fuse. So, given I don't have dash gauges/lights when the car won't turn on or turns itself off it should be a problem within those circuits. Also since I'm not blowing fuses, could it just be a bad connection in the white with black stripe wire supplying power to the reverse circuit being overloaded, then the relay for fuel turns off?