colfax

2007 460 with 126,000 miles,
I went out to start the car and the dash lit up and it made an odd loud noise.
Tried again and this time no power to the dash.
Just got a new battery installed and again tried to start it, started but again loud long noise.
I was told that the starter SOLENOID has failed.
I am having it towed on Monday to my trusted mechanic.
Can someone educate me what a starter solenoid is and does and could this making the loud long noise?
The battery I replaced was less than one year old and I was told it had a "deep short"
Could this have happened because the starter solenoid kept draining the battery ?

Protholl

Normally a solenoid that isn't functioning well isn't terribly loud but it clicks. You should only hear it when you try to start the car. The solenoid is an electromagnet that engages the starter's gear with the flywheel when you start the car. Once the car starts the electromagnet releases and the gear pulls back from the flywheel.

The description you're giving sounds like something is a dead short or your battery is really worn out. A "dead short" just means the battery has sulfated enough over time to ruin it.

I've never seen a solenoid drain a battery because it is only in use when you start the car. FYI: I'm not a mechanic I've just worked on cars since I was a kid.

Here is a video from youtube - in it you'll hear the solenoid "clicking" noise.

SW17LS

A bad starter solenoid can absolutely drain the battery. Sometimes they fail "open" so they are constantly drawing the power needed to start the car, and that depletes the battery quick.

ALK

I had my starter fail one year ago. When you click you can hear something rotating then stops . I kept it overnight luckily the solenoid was not stuck open .

Protholl

Thanks for that. I've never seen it happen but that is why I gave the FYI I'm not a mechanic note.