How to get my yorkie to sleep through the night

Question
I have adopted a Yorkie who is now 3 1/2, he has been here 17 month now. He was my son's and his girlfriends dog.  They broke up, she took the dog then he got the dog back. His new girlfriend didn't want Mojo. So I took him. I had 2 schnauzers when Mojo moved in. My problem is he only wants to be with me a night. Until recently he would sleep maybe 5 hours upstairs with my son.  Since one of the Schnauzers has passed 3 weeks ago, Mojo will not stay upstairs.  I do not know what to do.  I am not getting any sleep.  My husband doesn't like this dog as it is, Mojo's not sleeping isn't helping the situation.  Please help me!

Answer
Is he loose at night? I'd be tempted to crate him in the bedroom (teaching him the crate first, of course) If he sleeps during the day, wake him up, and make sure he gets plenty of mental and physical exercise. If it's an anxiety issue, you might want to consult your vet about anti-anxiety drugs, also possibly a little melatonin might mellow him out at night (but ask your vet before using it.) Sandy Case BFA, MEd CPDT www.positivelycanine.com