Electrical problem

I have a 2005 Ford Focus, we bought it used. On occasion it loses power(electrical) and won’t start I hear a relay clicking faintly but no attempt by the starter to engage. when this happens the am/fm radio will lose the presets and will actually come on by itself at a am mode and static. when this has happened I have touched various electrical components (battery posts fuses relays etc) and most times on the next try it will start. Sometimes you turn the key back on a couple of times and it starts immediately . I have had this happen twice while driving down the road and not noticed any change except the radio comes on by itself and presets and clock needs to be reset.
I have pulled all fuses and relays to check for any corrosion and plugged all connection etc in and out all looks ok
This might only happen once a month or if vehicle is left setting for a few days Battery is new and checked at 97% unit starts up immediately if problem is not there and it doesn’t seem to matter what you touch or move it just starts when it wants to
Ford dealer says it needs a new battery (doesn’t comment when told it is new and battery and starter work fine when called on except for this glitch)
any ideas appreciated!!!

When this happens while driving, the engine doesn’t quit on you? Did this happen before you got the new battery? If not, then it can be the battery.

I guess the first thing I’d try if this were my car is to remove the battery connections, and clean both the terminals and the connectors with one of those battery post cleaning tools, then re-tighten. That may be all you need to do to fix it.

With a poor (high resistance) connection at the battery post, the battery could test perfectly fine, but when drawing high current loads, like the starter, there would be significant voltage drop across the connection and show up as low voltage in the wires going to the rest of the car, which could affect all the electrical systems in the car, as well as preventing the starter motor from cranking properly. Temperature can affect this also, as the metal can expand and contract, making a good connection sometimes, but not others.

Keith no problem or hesitation at all the radio came on to static am channel and time was 1200battery was new Napa battery when we bought it load tested 97% capacity

George the connections were all redone and I’ve also checked with a voltmeter for any voltage drops no sign of any corrosion. I also pulled all frame grounds and cleaned them and the frame areas Temperature was spring Florida so not bad checked all connections I could find (starter fuse/relay boxes firewall) no signs of problem I evencranked radio up and wiggled all connections hoping to get a reaction no luck
When it sets for a few days seems to aggravate it sometimes but nothing is constant can happen twice in one day then not for a month

I don’t have experience w/modern day Fords, but my Corolla has a set of 3 specialty fuses located very near to the battery, part of the battery cabling – I forget right now what these are called – anyway, all the current has to pass through these fuses for it to get to the rest of the car, except the main power to the starter motor, that wire due to the high current capacity required, has no fuse at all. If one of those fuses were cracked, that could cause the symptom you are reporting.

They are called fusible links

Thanks @db4690, yes, that’s the term.

did not see anything like those links will check schematic. Any ideas why radio comes ON when this happens??

I expect the radio is being reset by a brief power outage or electrical noise glitch caused by a brief power outage, and so when normal power is resumed it turns back on, and enters its reset state, which apparently is AM mode andset to a frequency that has no local transmitter in our area, so you hear nothing but static. With solid state electronics, if they are not supplied with a clean steady power source, pretty much anything can happen.

It sounds to me like you have a failing connection. The clicking means you are not getting enough juice to the starter. Clean and check the battery connections, and connections at the other end of the battery lead would be my first shot.

This IS being caused by an intermittent poor connection with a cable that carries a lot of current. The problem is finding it. Gremlins like this can be a real bear to troubleshoot. Maybe the best way would be to have someone hold the key to start when this fails, and wiggle everything under the hood until something happens. (might be a good idea to wear goggles and gloves too while doing this)