Fast idle, dash gauges quit working

Welcome to 2CarPros.

The first thing we need to do is confirm the battery is good, the connections at the battery are both clean and tight, and make sure grounds to the engine and body from the battery are good.

First, a very weak battery can cause what you have described. I'm not sure why you must roll start it, but if it is because the starter won't engage, then it could be related to the battery as well. All the things you mentioned sound like that is the issue. If the battery is new, then suspect the alternator may not be doing its job or you have a loose or corroded connection.

Lets start with a simple battery load test. Take a look through these links. The last one is how to load test the battery at home.

https://www.2carpros.com/articles/how-a-car-battery-works

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

https://www.2carpros.com/articles/symptoms-of-a-bad-car-battery

https://www.2carpros.com/articles/car-battery-load-test

Lets start with that. I need to make sure we have power where needed and enough.

I will watch for your reply.

Joe