Explorer Starts... Sometimes

My first two suspects would probably be the ignition switch and the positive battery cable. The cables tend to deteriorate inside the insulation.

Are the bolts on the starter tight??? Where the conditions similar before the starter replacement? Is te replacement starter a good quality unit or was it selected with pricing as the driving factor? Was the rest of the system serviced at the same time? (battery connections, grounds, battery test...). Why was the original starter replaced.... could the ring gear be bad?

You got me thinking--I once had a starter motor that didn't work while installed but worked fine when out of the vehicle. It turned out to be worn brushes and it would make contact if the starter was turned a certain way. Maybe OP got a poorly assembled rebuilt.

Some rebuilders (I don't know f this is just a Canada thing or not) are offering an "economy" line of rebuilts... These units are basically "reconditioned" rather than "rebuilt". I don't think I would use these on any of my vehicles.

Here in California we generally have a choice of 3 different grades of rebuilt: Cheap with a very short warranty, Medium price with a 1 year warranty, and Expensive with a lifetime warranty (or at least several years). I believe that at least part of the price is the warranty period but nonetheless I agree and never buy the cheapest part.

I had the same problem a couple years back on my '91 Explorer. It would only happen sometimes. I would have to giggle the positive battery cable and it would eventually start. I replaced both battery cables. Two years and I've never had a problem since.

I had the same problem a couple years back on my '91 Explorer. It would only happen sometimes. I would have to giggle the positive battery cable and it would eventually start. I replaced both battery cables. Two years and I've never had a problem since.

ph