I just accomplished an engine change by installing a used engine. When trying to start it after engine change I only hear a faint click; starter never tries to engage. It's a new starter. The starter main terminal has 12.5v. The alternator output terminal also shows 12.5v. The fusible link at the battery goes to this wire.Looking at the car from the front looking back it would be fusible link on the far right (end. with the 90 degree terminal end). This fusible link blows.

When turning the ignition off I hear a low whining coming from somewhere in the engine compartment. I think there must be a wire hooked up incorrectly or something but I don't even know where to begin. Any ideas out there? It is really starting to stress me.

 

Welcome to the forum

 

Before going further to need to FIRST check the battery health by way of a load test. Your voltage reading as they are inconclusive.
There is other voltage test you could do but until you first confirm the battery as not part of the issue I can't advise further.

I would also as well other need to know the year, trim and engine size and mile on the chassis.
Basically, the winning noise you hear from your description may be normal but without complete information it's hard to even guess.

 

Failed to mention that. It's a new battery. 2016 Mazda CX-5 Grand Touring 2.5 L front wheel drive. Original miles is around 107,000. Still in great shape otherwise.

 

Ok that means nothing!!!
I hear that several times a week from customers and then show them their battery is bad or will not pass a Load test. They intern must go back to the store they got it from and that auto parts or service shops then discards my test and does their own. The customer then returns with a WOW you were right that new battery is bad.!
The thing is you have no idea how old that battery is or how it was serviced before you purchased it?

The point that you are getting only 12.50 volts for a new battery is a clue for me that something may need to be addressed FIRST!!!

 

I just realized that your thread title is far different then the information you provided none of which indicates and you stating any fuse blowing??

 

Just had the battery checked. It's a Duralast 35DLG, CCA Rating 640 State of Charge 89% 874 Amps at test Reserve Capacity Pass Battery Pass.
As to the fusible link this is the one at the battery positive terminal. Only the one at the far right 250A blows. The wire coming from this terminal is the wire that powers the starter and then hooks up to the alternator. Hope this helps to clarify things.

 

I would agree. I will look over the wiring again for obvious errors. I did have to swap the complete wiring harness from my original engine to the used engine I installed. It seemed pretty intuitive though.

 

That fuse is a major power supply and blowing as you describe means that the cable likely got damaged and is grounding? (GUESS). It is very strange that you measure 12.50 volts even after all the attempts to start with the other electrical power sources. It should have at least dropped closer to 12.0 or even into the high 11s? The main battery routing is pretty cut and dry the battery ground goes directly to the frame or strut tower. And the positive via the fuse to the alternator and alternator to starter. So unless your new starter is shorting out during start procedure then the problem cable can easily be tracked from battery to starter. These are assumptions that other things were not damage during the engine swap and a lot of basic guessing. The starter is easy to check either just pull it and bench test it or run a lead from the solenoid directly to the battery and momentarily touch the positive terminal to activate the starter. Make sure key fob is not close to the car when you do this just in case.

 

Thanks for your response. I'll look it over and see what I can come up with.