I have a 1989 JCB1400B. It would not crank. After much searching/testing, I finally figured out it is the starter relay. Figured this out by disconnecting the wires from the switch and holding them together, then turned the key and it cranked right over and started. I am a newbie at the whole backhoe/equipment game. So my questions are, what does this relay do? I assume it must have some safety or charging related to it being needed. Also, it is a Lucas 33RA 12v (or SRB600) , it appears that those numbers may not be a very common part and are not easy to find. I was wondering if maybe someone knew of another part number that I may be able to get at someplace like a NAPA. Or maybe it just needs to be any relay that does ? and ? and I could get it anywhere if you know what I am saying.
If all you need is a starter relay, go to the local auto parts store and get a Ford starter relay. But, I don't know if you have any other functions built into your Lucas bit, that, you'll have to work out. Did a little looking at the Lucas part, that's described as a split charging relay; didn't mention a starting function, only listed as a 60 amp relay. Not sure how that ties into the starting circuit and exactly what else won't work without a functioning one in place. You can get them from England, they air mail it in less than a week. I've bought motorcycle parts out of England and it's not difficult or expensive....
That is just a 4 wire relay. + from ign switch that activates the coil which is the starter contact. 12V+ from switch goes through to ground to close the coil, 12V in from batt goes to starter when coil is energized. You need a parts store with old guys instead of those kids that have to know what year model ect to find a part. Old guy will know what you need, it's just a relay. Kid probably won't know what a relay is. Joe H
A relay is a relay, there pretty much all the same, just get one with the right (same) amp rating. The relay your talking about "could" be a neutral safety relay, In other words, your machine has to be in neutral for this relay to become active and supply juice for the starter.
Thanks for the replies. From looking and trying to follow the electrical diagram for my machine, it appears that hookedondiesel is correct, i think the other wires on the relay are from the forward/reverse selector to act as a neutral safety. So with that being the case, I would think a relay of similar setup would work, just don't know how to figure out which one will do that until I find an autoparts veteran.
http://www.autoelectricsupplies.co.uk/file_uploads/srb600_data_sheet_2.pdf
Bring the old relay to an automotive store etc, Napa etc....don't need to match the numbers, just the amperage of the relay, yours is probably a 40amp 4 pin relay,
Puma1973 When you say you touched the wires together was it the two larger wires if so yes you bypassed the relay and it will start . Does your machine have dump buttons on gear stick if manual gears and also on loader levers which dump the transmission into neutral when still in gear f/r lever position for loading ect which work on switching side of the relay ie the smaller wires (switching wire and earth wire ) not sure if this helps at all.