I have a ford fiesta courier 1.8td. Here is what I have done so far...

Changed dud battery (checking & cleaning connectors), c
hanged the fried starter motor for a new one.

Firstly I thought I did it wrong as couldn't get it started. took it off, noticed bendix gear was stiff & gear wasn't coming out easy so WD40'd it, making sure gear was free to come out, tapped solenoid a few times (for good measure) Started it up - fine. Today, wouldn't start so I had to call breakdown people as I didn't have anyone else to help me. SO, jump started the car (volts on battery fine). NO joy, we bridged the big positive post on solenoid to the other big post that goes to starter (leaving the little post alone), it started. OK so now I called to ask for an exchange on starter as the guy who helped confirmed it was sticking solenoid, but the supplier of starter is arguing with me its ignition switch.... (all was fine till I fried old starter LOL) Can you help as I don't want to go down ignition switch route?