Anyone have any ideas?

Background - Car has been sitting all winter. I started it awhile ago via jump. Car horn sounded incessantly until I removed the fuse. later, I replaced the OEM radio with another unit - now? Nothing. Is there something I jacked up with regard to the anti-theft? What am I missing? Car cranks with no start - cranks weakly. All fuses are fine. Is the non-start even related to the new radio unit?

 

Is the horn still an issue if you put the fuse back in? Does it sound like the alarm is going off?

Is the immobilizer light flashing?


If it isn't cranking strong check your battery connections and the voltage of the jump battery

 

Thanks Dan - No flashing anything in the gauge cluster when cranking. Jump-battery is fine - starts my Expedition perfectly. I'm unsure if I've replaced that horn fuse on second thought, but I'll get at it again, but yes, when the horn was blaring it was the alarm-sound horn. I'll get the voltmeter out and double check.