Electronics completely failing at random

[Jake]

This is a perhaps-more-detailed version of what's in my E34 project thread. Hoping someone will have some ideas (thanks, Adam, for yours - will check battery terminals)

My ignition switch had been failing over the summer. I wired in a push-button start that essentially crossed the two wires to run the starter. Worked fine. Finally bought an ignition switch from a parts car so I was planning to install it last week.

Starting procedure had been insert key, turn to Run, press/hold button.

Flash back to last Monday. I go with Joey to lunch. We eat, get back in the car and I put the key in. Turn to Run, dash comes on as it always does and says Fasten Seatbelts. I hit the starter button and IMMEDIATELY everything electronic cuts out.

Tried cycling the key, no dice. After a few minutes, the Brake Fluid light came back. Then the other lights and electrics came on - OBC was reset, radio was reset, like the battery had been disconnected.

We had the same song-n-dance go on for a few minutes until I finally push-started the car once the electrics came back for the umpteenth time.

Disconnected the switch and manually crossing the wires worked fine. Installed the parts-car ignition switch and it worked fine too.

This past Saturday rolls around and I get gas. Fill up, insert key and twist, and nada. Everything goes. I wait a few minutes, push the car backwards to get ready for a push start, and BOOM they come back on with everything reset.

I've had some hesitant starts over the course of the week, like the switch wasn't totally engaging the starter or something. But, with all of those, it was one hesitant clunk of the starter and then everything was fine.

So, I'm not sure if it's the starter going bad or what it could be. Some people have suggested a bad ground somewhere. I checked the fusible link under the back seat and it's fine.

I'd think a failing starter would cause the hesitant starts, but not the total loss of electricity. Am I right, or is that what I likely need?

[Goodspeed]

Sorry, had to.

[Scott]

After 21 years and 200k everything still works on my DD beater Miata......

[D_Eclipse9916]

After 21 years and 200k everything still works on my DD beater Miata......

But then you drive a miata :wink:

[Scott]

After 21 years and 200k everything still works on my DD beater Miata......

But then you drive a miata :wink:

Exactly, I actually get to drive mine :bootyshake:

[NTIman]

If the battery and terminals are ok, I'm imagine it's the starter. If there is an issue and it is drawing too amperage, I could see you losing the juice required to run the electronics.