Solomon had lapses because of greed and lust. He just had to have more horses and more wives. Kings were not to multiply horses:

Deuteronomy 17:14. “When you have come to the land which the LORD* your God is giving to you and possess it and live there and say, ‘I shall set a king over me, like all the nations that are around me,’ 15. and you in any way set a king over you, whom the LORD* your God will choose from among your brothers you will set a king over you. You may not set a stranger over you, who is not your brother. 16. #1. But he will not multiply horses for himself, #2. nor cause the people to return to Egypt, to the end that he should multiply horses since the LORD* has said to you, You will from here on not return that way. 17. #3. Neither will he multiply wives to himself, so his heart will not turn away, #4. nor will he greatly multiply silver and gold for himself. 18. And it will be when he sits on the throne of his kingdom that #5. he will write for himself a copy of this Torah in a scroll out of that which is before the priests, the Levites. 19. And it will be with him and he will read from it all the days of his life, so he can learn to revere the LORD* his God, to keep all the words of this Torah and these statutes, to do them 20. so his heart will not be lifted up above his brothers and so he does not turn aside from the commandment to the right hand, or to the left: to the end that he may prolong his days in his kingdom, he and his children, in the midst of Israel.”