padwag23 Posted May 27, 2011 Share Posted May 27, 2011 (edited) aaargh, it's an MJ not MK, anyway... if I turn the ignition one click, it drains the power instantly...the volt metre can't keep up withthe numbers dropping. if i turn it all the way it starts and the alternator holds it around 24v, but if i put on any electrics, fan, wipers, it falls down to 22v. if i stop the engine at this point then there's not enough power to restart. I something is draining the power...how do i find it? is there a common faullt that i could check first? any suggestions greatly received, paddy wagon. Edited May 27, 2011 by padwag23 Quote Link to comment Share on other sites More sharing options...
Tony B Posted May 27, 2011 Share Posted May 27, 2011 First put a proper battery tester, one that loads across the batteries. Second check that the battery connections are tight and clean, don't assume beceause you can't move them they are OK. That might be two obvous problems. Electrolyte levels in battery! If they are sealed unit batteries they have a nasty habit of sudden death. Quote Link to comment Share on other sites More sharing options...
andym Posted May 28, 2011 Share Posted May 28, 2011 24V is low for batteries being floated across the alternator - I'd expect around 28V otherwise the batteries won't be charging. Andy Quote Link to comment Share on other sites More sharing options...
padwag23 Posted June 7, 2011 Author Share Posted June 7, 2011 An auto spark friend tested all the circuits and located the power drain in the starter motor. I've taken this off (picture attached) and had it bench tested, it's working perfectly normally. but, when I looked at the wiring I noticed that the little round socket plug (picture attacted) has loose wires. (the wires are attached to the back of the socket and this plugs into the starter). these wires are or were being held in to the socket with sillicone sealant, a bodge. do you know anyone who could re-connect these wires? I'm in manchester, or have a wiring diagram? is there something missing from this socket plug and that is why sillicone has been used? One other question. look at the photo of the starter. there's two terminals at the very end of the starter on the round face. when I disconnected the started all the wiring, including the earth strap was on the left had terminal. there was nothing on the right hand one. but as you can see there is a snipped off bit of bared copper wire on there so it was connected to something at one point. What is this terminal for? any reason why there was nothing connected to it? NB although I got this MJ straight from Whithams, I did have a this replacement starter put on by a civvy garage and the sillicone bodge is theirs, not witham's nor the MOD's. any help, advice, contacts greatfully received as I have only one week to get this vehicle back on the road....paddy wagon. Quote Link to comment Share on other sites More sharing options...
robin craig Posted June 16, 2011 Share Posted June 16, 2011 be it said that I am electrically stupid. That is the same starter as on J60s and Stormers. Im thinking that there is a rubber bushing missing hence silicone. Think others here would have more concrete advice for you. R Quote Link to comment Share on other sites More sharing options...
Stormin Posted June 17, 2011 Share Posted June 17, 2011 If the starter was wired as you say and the earth strap was wired to the same terminal as the main positive feed it's no wonder the batteries voltage dropped as soon as you switched on. The earth strap should be to the body of the starter not the live input terminal. Sounds like your truck has been messed about with a bit and a visit to a proper Auto electrician may be in order. I know of an Autospark near Rochdale that should be able to re-connect or replace that multi-plug. What's the reg of your MJ? Used to have one myself a few years ago but it's been sold on a few times since. Was a very tidy truck when I had it. Quote Link to comment Share on other sites More sharing options...
Matthes Posted October 25, 2012 Share Posted October 25, 2012 Hello, I have now nearly the same problem with the connecting of my Bedford MJ starter. Three cables - two small (diameter) and the earth cable are connected with the "fat" screw (picture). Does anyone have a picture or wiring diagram? Thx in advance! Greetings from Germany Matthes Quote Link to comment Share on other sites More sharing options...
FourFox Posted October 26, 2012 Share Posted October 26, 2012 The two terminals on the end of the starter are the main earth strap (the big one) and a thermostatic cut out (the small one). The 4 pin plug at the flywheel end of the starter carries the solenoid terminals. There are 2 wires for the solenoid initiation (when you switch to cranking) and the other 2 are the earth return for the solenoid. These are pared in opposite corners of the plug (diagonally) and are usually joined up in pairs. The current required for solenoid operation is too great for a single wire. The 2 solenoid earth wires are usually routed via 2 short wires to the big earth terminal on the rear of the starter, together with the earth strap. The small terminal on the end of the starter is usually connected to the vehicle control box where an 'earth' signal is required in order to operate the starter relay. It is supposed to prevent the starter operating when the internals of the starter have got too hot and the safety cut-out has operated. The positive battery feed to the starter goes to the 'peg' terminal on the flywheel end of the starter (alongside the 4 pin socket. The symptoms you have described are not obvious and could be for a number of reasons. Any drain on the ignition circuit, including wipers, horn, indicators or the complicated lighting wiring could be the cause. Battery and/or alternator faults are the most common (especially after someone has connected the battery up the wrong way round for a fraction of a second and fried the alternator diodes). I have even seen someone connecting the batteries to a slave vehicle the wrong way round (a well known dealership who should know better). It is possible that the thermostatic cut out signal wire has been mistakenly re-connected to the 4 pin plug. This is no problem on the 2 earth wires but would give a dead short accross the thermostat if connected to the solenoid operating wires. Keep us posted. Jon Quote Link to comment Share on other sites More sharing options...
Matthes Posted October 26, 2012 Share Posted October 26, 2012 Hi Jon, very helpful!!!! Thank you! If the new starter is fitted....I will give a further information. Regards Matthes Quote Link to comment Share on other sites More sharing options...
Matthes Posted November 6, 2012 Share Posted November 6, 2012 Hi, update: The reconditioned starter is arrived and it works. Three cables (incl. the"fat" earth-band) fittet on the 8mm srew. Regards Matthes Quote Link to comment Share on other sites More sharing options...
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