Starter/Solenoid troubles (95 Mitsu Pajero/Montero)
Discussion
You lot are always knowledgable about maintenance stuff so.... (and I haven't got a useful respons from the Pajero forum yet)
I went on holiday a few weeks ago and the (not my - it's on loan to me) Montero was working fine when I left. But since returning a couple of weeks ago I haven't been able to start it. Initially I thought it was just a flat battery after being away for 11days so I borrowed a van from work and tried boosting it. That didn’t work and the original battery still had enough power to light the headlights so it wasn’t that.
There's some micky mouse wired in push button starter (an anti-theft measure installed by the previous owner) that I thought it could be but that appeared to be transferring current to the solenoid only when pressed as expected (apart from the fact that the wire covering was melted almost all the way along its length - under-rated??).
The next step was checking the starter assembly. Using jump leads direct from the battery to the motor had it spinning no problem so it must be the solenoid. The solenoid did nothing when connected directly with jump leads so I removed it and confirmed it wasn’t working and purchased a replacement. The replacement worked first time when I test-hooked it up with jump leads so I’ve just installed it. Once I’d connected up the cabling on the car the solenoid would again not move. It appeared to get very warm as if it were energised continually and thus upon subsequent removal and testing it looks like it’s been burnt out. So somewhere along the way there appears to be an issue with its supply wiring.
a few days later.....
Turns out this starter button was an "anti-theft" measure by the pervious owner but as far as I can work out all it was was a push-to-connect switch inline from the battery +ve to the small solenoid terminal (S terminal in the Chilton manual). I've disconnected it as best I can and after removing the steering column covers there doesn't look to be any damage to the lock/ignition loom.
The solenoid has 2 wires going to it. One heavy one on the B terminal direct from the battery (which I presume ultimately powers the starter motor), and one smaller one attached to the S terminal (which I presume is the"start" signal from the key ignition). I've got a couple of questions re those wires. I trust that the heavy B terminal wire is continually energised (so 12v ish) but the other one I'm not so sure of. Using a multimeter it was measuring something like 8v (may have a slightly dead battery) continually once the ignition key was on (in both the "run" and "start" positions). It didn't climb as I expected when the key is turned to the "start" position. And when turning off the ignition and removing the key, the voltage remains at around 8v for a few seconds before there is a quiet click (relay?) somewhere in the dash.
Does this sound like normal operation? I was expecting nothing along that S terminal wire until the key was temporarily twisted to the start position where it would activate the solenoid. And then an immediate drop to 0v when the key is back i the normal run position. This "fault" may explain why the replacement solenoid I fitted got so hot (and then burnt out I guess) in such a short period. Is there supposed to be a relay on the ignition switched feed to the solenoid?
Any help guys. (I really want to get this vehicle running so the owner can come and collect it from me and allow me to buy myself a raliabal motor)
I went on holiday a few weeks ago and the (not my - it's on loan to me) Montero was working fine when I left. But since returning a couple of weeks ago I haven't been able to start it. Initially I thought it was just a flat battery after being away for 11days so I borrowed a van from work and tried boosting it. That didn’t work and the original battery still had enough power to light the headlights so it wasn’t that.
There's some micky mouse wired in push button starter (an anti-theft measure installed by the previous owner) that I thought it could be but that appeared to be transferring current to the solenoid only when pressed as expected (apart from the fact that the wire covering was melted almost all the way along its length - under-rated??).
The next step was checking the starter assembly. Using jump leads direct from the battery to the motor had it spinning no problem so it must be the solenoid. The solenoid did nothing when connected directly with jump leads so I removed it and confirmed it wasn’t working and purchased a replacement. The replacement worked first time when I test-hooked it up with jump leads so I’ve just installed it. Once I’d connected up the cabling on the car the solenoid would again not move. It appeared to get very warm as if it were energised continually and thus upon subsequent removal and testing it looks like it’s been burnt out. So somewhere along the way there appears to be an issue with its supply wiring.
a few days later.....
Turns out this starter button was an "anti-theft" measure by the pervious owner but as far as I can work out all it was was a push-to-connect switch inline from the battery +ve to the small solenoid terminal (S terminal in the Chilton manual). I've disconnected it as best I can and after removing the steering column covers there doesn't look to be any damage to the lock/ignition loom.
The solenoid has 2 wires going to it. One heavy one on the B terminal direct from the battery (which I presume ultimately powers the starter motor), and one smaller one attached to the S terminal (which I presume is the"start" signal from the key ignition). I've got a couple of questions re those wires. I trust that the heavy B terminal wire is continually energised (so 12v ish) but the other one I'm not so sure of. Using a multimeter it was measuring something like 8v (may have a slightly dead battery) continually once the ignition key was on (in both the "run" and "start" positions). It didn't climb as I expected when the key is turned to the "start" position. And when turning off the ignition and removing the key, the voltage remains at around 8v for a few seconds before there is a quiet click (relay?) somewhere in the dash.
Does this sound like normal operation? I was expecting nothing along that S terminal wire until the key was temporarily twisted to the start position where it would activate the solenoid. And then an immediate drop to 0v when the key is back i the normal run position. This "fault" may explain why the replacement solenoid I fitted got so hot (and then burnt out I guess) in such a short period. Is there supposed to be a relay on the ignition switched feed to the solenoid?
Any help guys. (I really want to get this vehicle running so the owner can come and collect it from me and allow me to buy myself a raliabal motor)
Well some solenoids it is possible to put them on backwards. The two big terminals are not the same as each other: one is intended to be connected direct to the battery, the other to the short bit of heavy wire coming out of the starter motor, and it matters which is which. If you get them the wrong way round the solenoid will be partly energised for as long as the battery is connected.
A multimeter is not always the best tool for checking voltages around looms because it has an impedance of around 10 megohms. Your starter control wire could be receiving a "feed" through an impedance of 5 megohms through dirt/damp/old insulation or whatever; this will cause your multimeter to indicate 8 volts (12 * 10 / (10 + 5)) but it's still open circuit as far as any real load is concerned. I often prefer to use a brake light bulb, which will draw a useful amount of current and give a realistic indication of what the real load sees... one wire from the bulb connected to earth and the other used to probe around things.
As far as the solenoid itself is concerned... fit a solenoid to the starter motor but connect only the heavy wire from the battery. Then test that terminal with the bulb: it should light full brightness. It should not light if used to test the other terminals. Then short the battery terminal to the control terminal (ie. the little one) with a screwdriver / pair of pliers / short length of wire etc. The starter should then turn the engine over.
If you've got the solenoid on backwards you'll be able to light the bulb off the control terminal as well as off the battery terminal, and nothing will happen when you do the short-the-terminals thing.
Leave the control wire disconnected from the starter and connect it to the bulb. Turn the ignition on: the bulb should stay off. Turn the key to "start" and the bulb should come on full brightness, then go off again when you let go of the key.
If the bulb doesn't come on it means that either the ignition switch is buggered or the wiring in between it and the starter is buggered. So the next stage is to take the cowl off the steering column or whatever else you need to do to get at the ignition switch terminals, and do the same test on the "start" terminal on the back of the switch. If it's too much of an arse trying to work out which is the "start" terminal, just test all of them in turn. There should be one where the bulb comes on when and only when you turn the key to "start". If none of them do that the switch is buggered.
If one of them does do it then take the wire off that terminal and connect it to +12V from the battery, then test the starter motor end with the bulb. It should light up... if it doesn't the wiring's buggered.
I rather suspect that you'll find the switch/wiring is indeed buggered, it has probably been buggered for some time and the "anti-theft" button business was actually a bodge to save fitting a new ignition switch.
A multimeter is not always the best tool for checking voltages around looms because it has an impedance of around 10 megohms. Your starter control wire could be receiving a "feed" through an impedance of 5 megohms through dirt/damp/old insulation or whatever; this will cause your multimeter to indicate 8 volts (12 * 10 / (10 + 5)) but it's still open circuit as far as any real load is concerned. I often prefer to use a brake light bulb, which will draw a useful amount of current and give a realistic indication of what the real load sees... one wire from the bulb connected to earth and the other used to probe around things.
As far as the solenoid itself is concerned... fit a solenoid to the starter motor but connect only the heavy wire from the battery. Then test that terminal with the bulb: it should light full brightness. It should not light if used to test the other terminals. Then short the battery terminal to the control terminal (ie. the little one) with a screwdriver / pair of pliers / short length of wire etc. The starter should then turn the engine over.
If you've got the solenoid on backwards you'll be able to light the bulb off the control terminal as well as off the battery terminal, and nothing will happen when you do the short-the-terminals thing.
Leave the control wire disconnected from the starter and connect it to the bulb. Turn the ignition on: the bulb should stay off. Turn the key to "start" and the bulb should come on full brightness, then go off again when you let go of the key.
If the bulb doesn't come on it means that either the ignition switch is buggered or the wiring in between it and the starter is buggered. So the next stage is to take the cowl off the steering column or whatever else you need to do to get at the ignition switch terminals, and do the same test on the "start" terminal on the back of the switch. If it's too much of an arse trying to work out which is the "start" terminal, just test all of them in turn. There should be one where the bulb comes on when and only when you turn the key to "start". If none of them do that the switch is buggered.
If one of them does do it then take the wire off that terminal and connect it to +12V from the battery, then test the starter motor end with the bulb. It should light up... if it doesn't the wiring's buggered.
I rather suspect that you'll find the switch/wiring is indeed buggered, it has probably been buggered for some time and the "anti-theft" button business was actually a bodge to save fitting a new ignition switch.
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