[Sahab]

Hello, hope someone can help.

My Civic is a daily driver, I turn it on without any significant issues. This winter I've had an engine light come on intermittently, the codes I got when scanned led me to a bad thermostat and fuel running too lean. My gas mileage got worse, but the car started with no problem with no real issues. The other day I took it to a coffee shop when I returned to my car it wouldn't start. As soon as I put the key into the first position, all electrics stopped working. Hazards, lights, no power whatsoever. I tried booting it, and the same thing, power would return for the first position and turn off completely.

I left the car in the parking lot and tried to boost the car the next day. When I arrived the power locks were working, tried to start it, and again no power, complete loss of power. Tried to boost it, and it would turn on again in the first position very briefly, and again no power.

I suspect it may be the Multi-Block Fuse 100A/70A or the 80A/50A

Will be replacing the fuses today. Would the cause of this problem be my starter or ignition switch/relay?

any help would be appreciated.

 

[Relic]

I'd say the battery was toast, or the alternator not charging it.
There have been some pulley issues on the alternators.
A dying battery will struggle even more in cold weather.
How old is it ?

If the fuse was done, surely you would get zero power.
Its the alternator that provides the energy when running.
The battery is there to start it mainly.

Also, is it turning over at all ?
Have you tried jump starting with another negative earth 12v car (with the keys out of the ignition initially) ?