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Post by donny1984 on Mar 12, 2009 11:32:32 GMT 11
Ok here is the deal...a little help would be much appreciated.
Went to start my 94 3.1ltr 4JG2 Mu the other day and the start relay just kept clicking away...would not hold on. I disconnected it from the starter side and left the battery side plugged in and it holds on fine. I thought that my start solenoid might be shot, so have bought a second hand starter complete with solenoid and fitted this. Now to my disapointment, having fitted the new starter and solenoid, the same thing happens....start relay wont hold on!! GRRRR!!
Any ideas on what could be at fault now?
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Post by geeves on Mar 12, 2009 14:38:08 GMT 11
First guess on every starter issue is low or faulty battery. Starter draws about 200 amps so a tired battery will drop in voltage when the load comes on resulting in not enough voltage to hold the solinoid in so it releases Then as theres no load the voltage comes up and the solinoid clicks back in etc.
If you have a voltmeter check the voltage at the battery. At rest it should read about 12.5 If you turn the headlights on it should drop a little but stay above 12 If you then try to start it should still stay above 10v.
Anouther thing to check is that the battery conections are clean and tight although the symptoms of this are slightly different
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Post by donny1984 on Mar 13, 2009 9:46:41 GMT 11
Yea I have suspected the battery, so have a jump pack with a voltmeter on it. When I turn key to start, the volts drop right down to pretty much zero....so does this mean I have a short in a wire somewhere?? Seems all the current is going somewhere...
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Post by geeves on Mar 13, 2009 12:25:03 GMT 11
Only time Ive seen that and it wasnt a flat battery was because the starter had self destructed internaly (front bearing gone and armature rubbing on the stator causeing big short) You say you tryed a second starter.
You could try conecting directly across the starter but be very carefull You are working with a circuit that will carry 200 amps in normal use and if it is a short like you think then 1000 amps is possible which will melt metal watches and rings and any flesh they are touching at the time if you let it
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Post by James W on Mar 13, 2009 15:19:25 GMT 11
it depends on where you measured the voltage? if on the battery terminals (the lead parts) will give you the battery voltage. But if you measured on the battery leads you are measuring the battery voltage minus any losses in the leads or terminals... which might be the problem, that is a bad connection somewhere. Which I would be suspicious of as it should have started with a jump pack.... although again depending on where you connected that. By choosing where you measure you should be able to figure out where the losses are.... the other possibility is as Geeves suggests, a nasty short... this should be evident with hot leads. An intermediate test is without the jump pack. measure the battery voltage and terminal voltage with everything off... and then again with progressively more load such as headlights high beam... This might show up very bad battery or terminals. But does not test the starting circuit... just the battery, terminals, and earth strap. The starting circuit being at least in part seperate. If you get a different battery voltage from lead voltage... then measure from each battery terminal to lead strap... the same one...i.e. +ve terminal to +ve lead... yes they should be the same thing... but if you get a voltage then there is a bad joint or connection between the two points measured. Cheers  |
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Post by geeves on Mar 13, 2009 18:11:49 GMT 11
Need to measure when trying to crank or with a load on. The voltage drop only shows if there is current flow.
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