Advice needed - Starting problem

[MikesDexta]

I've just completed a refurb of the brakes on my 1959 Dexta, including oil seal replacement. I also refurbished the steering column and improved the rear linkage (still looking for a spare RH Lift Arm) and whilst I was about it I performed a rewire...and this is where my problem began.

I had no starting problems before I started this phase of the restoration; the starter motor is a relatively poor repro but worked and it has a newish repro push button solenoid. When I came to fire her up it became clear that the solenoid wasn't switching but it fired up no problem using the push button and I spent a happy couple of hours topping nettles.

Today was a disaster, I pressed the starter lever and the push button and the bendix shot out but making the most horrendous din; pulling the lever back seemed to make it worse, the starter began to overheat and smoke a bit and I had to disconnect the battery to stop it. Removing the starter motor revealed a bevelling on the bendix and fly wheel but all teeth appear ok. Effectively this would only be caused by the solenoid contacts sticking closed but what would cause this? I then tested the solenoid with the starter cable disconnected and it clunked when I pressed the starter lever but there was no continuity between the large terminal posts so nothing would get through to the starter motor once connected up. This is all most bizarre so I need help with the following questions:

1. Why, after it started several times yesterday would it suddenly fail in the way it did today?
2. I need to replace the solenoid but this will be the 4th I've got through (the first failed due to poor starting causing it and the starter motor to overheat, the 2nd was fitted together with the repro starter after a major engine rebuild and failed when the engine became stuck after rain water got in after a storm blew open the exhaust cap. I've no idea why the 3rd and current one failed. So can someone tell me which solenoid I need that will be more robust please? I am reluctant to fork out £80 for the Agriline Lucas one in case I burn that out as well so should I opt for a non-standard square one that is cheap enough to gamble with? What about a Durite at around £40 - if so which do I need?

thanks
Mike

ps the brakes are excellent!

[basewindow]

Im no expert but the solenoid can get stuck closed for a number of reasons. Is the battery well charged and holding charge? Low voltage can cause the solenoid to get stuck like this with arcing and heating of the contacts.
Possibly bad luck and you've got faulty solenoids.
If you did some rewiring did you replace it all properly and with the right guage cable/wires?
Have any of the wires/cables burned or melted and which side, pos or neg.

Cheers,
Cam

[MikesDexta]

Hi Cam
The battery is good, I used a wiring harness from Agriline here in the uk and all the wiring looks fine. What is weird is that the solenoid contacts must have been fused to have caused the problem but unfused when I disconnected the battery and now there is no continuity between the large studs either when I apply 12v to the small stud (it just clicks but doesn't close the contacts) or manually when pushing the button.

I still have the lucas solenoid that came with the tractor and so I tested it without connecting to the starter and it appears to work so will try it connected later.

The solenoid that has failed is exactly like this - 4 posts with a date sticker on the front. It needs to be earthed to work.

https://www.ebay.co.uk/itm/12v-universa ... Sw5ZBWJgvk

[MikesDexta]

Here's an update on the starter problem. It looks like the starter lever was fouling on the new starter power cable I installed as part of the rewire; it had kinked outwards jamming on the starter lever rod. This would explain why it was fine on Sunday but not on Monday - the cable must have moved with the vibration when I was out topping a paddock.

I then installed my old Lucas solenoid but no joy - it just clicks, so I've ordered a cheap one from Agriline until I am happy it all works and nothing else blows, I will then swap out the cheap unit for a lucas and also install my original lucas starter motor that I paid an arm and leg to have rebuilt.

[MikesDexta]

Well it was the solenoid, I fitted one of the £10 square ones from Agriline just in case and it fired up absolutely fine. It was a relief that the starter appears to be ok as I'm saving my restored lucas one until next year when I restore the tinwork and paint it.

[basewindow]

Good to hear she's going well again