How to get manufacturer of a mobile home to make repairs?

If there is an existing contract between you and the manufacturer of the mobile home, you could sue the manufacturer for breach of contract.

Is the mobile home under warranty?  If there is an express warranty that is still in effect, you could sue the manufacturer for breach of the warranty.

You could also sue the manufacturer for breach of implied warranty.  There are two types of implied warranties which would be applicable as the basis of your lawsuit.  First, there is breach of the implied warranty of merchantability.  This means that the mobile home has to be of a quality acceptable in the trade.  The "major problems" would provide evidence that the manufacturer has breached the implied warranty of merchantability because the mobile home is not of an acceptable quality in the trade.  Second, there is also an implied warranty of fitness for a particular purpose.  The manufacturer breached the implied warranty of fitness for a particular purpose if the "major problems" are preventing you from using the mobile home for its intended purpose as a residence or a vehicle, etc.

You would file one lawsuit against the manufacturer in which each of the above  would be separate causes of action (claims) in your lawsuit.

Another potential cause of action(claim) in your lawsuit against the manufacturer would be negligence based on products liability.  Products liability is an area of law dealing with defective products.  In a products liability claim, you could sue the manufacturer and the seller of the mobile home even if the seller had no knowledge that the mobile home was defective.