If the map marker / pin is not being displayed it’s problem because Google wasn’t able to find the “address” you set.
The easier way to fix that is to set the map using latitude / longitude:
Example:

FROM:
var mapMarkers = [{
address: "New York, NY 10017",
html: "<strong>New York Office</strong><br>New York, NY 10017",
icon: {
image: "img/pin.png",
iconsize: [26, 46],
iconanchor: [12, 46]
},
popup: true
}];
TO:
var mapMarkers = [{
latitude: 40.75198,
longitude: -73.96978,
html: "<strong>New York Office</strong><br>New York, NY 10017",
icon: {
image: "img/pin.png",
iconsize: [26, 46],
iconanchor: [12, 46]
},
popup: true
}];