.slider {
  max-width: 80vh;
  height: 53vh;
  margin: 20px auto;
  position: relative;
}
.slide1,.slide2,.slide3,.slide4,.slide5 {
  position: absolute;
  width: 100%;
  height: 100%;
}
.slide1 {
  background: url('images/mantenimiento/1.jpg')no-repeat center;
      background-size: cover;
    animation:fade 16s infinite;
-webkit-animation:fade 16s infinite;

} 
.slide2 {
  background: url('images/mantenimiento/2.jpg')no-repeat center;
      background-size: cover;
    animation:fade2 16s infinite;
-webkit-animation:fade2 16s infinite;
}
.slide3 {
    background: url('images/mantenimiento/3.jpg')no-repeat center;
      background-size: cover;
    animation:fade3 16s infinite;
-webkit-animation:fade3 16s infinite;
}
@keyframes fade
{
  0%   {opacity:1}
  33.333% { opacity: 0}
  66.666% { opacity: 0}
  100% { opacity: 1}
}
@keyframes fade2
{
  0%   {opacity:0}
  33.333% { opacity: 1}
  66.666% { opacity: 0 }
  100% { opacity: 0}
}
@keyframes fade3
{
  0%   {opacity:0}
  33.333% { opacity: 0}
  66.666% { opacity: 1}
  100% { opacity: 0}
}