No ignition light, no crank of engine when key turned,
Discussion
Hi,
Confused and need a little advice where to look first.
Engine is a Rover V8 with carbs, Megajolt ignition system.
The lights, horn all the usual pre ignition stuff comes on as usual however when i turn the key to the first click ready to start the ignition light does not come on, the fuel pump does not power up and all the other stuff like indicators, brake lights, oil warning light etc does not power up and no crank when i turn the key.
The ignition key does not appear to have any loose wires and the Megajolt lights up ok.
Is there a fuse in this part of the circuit ? Or where do i start looking to eliminate items,
Regards
Martyn
Confused and need a little advice where to look first.
Engine is a Rover V8 with carbs, Megajolt ignition system.
The lights, horn all the usual pre ignition stuff comes on as usual however when i turn the key to the first click ready to start the ignition light does not come on, the fuel pump does not power up and all the other stuff like indicators, brake lights, oil warning light etc does not power up and no crank when i turn the key.
The ignition key does not appear to have any loose wires and the Megajolt lights up ok.
Is there a fuse in this part of the circuit ? Or where do i start looking to eliminate items,
Regards
Martyn
Do you have a handbook with wiring diagrams?
Assuming a conventional ignition switch system. Normally no fuses involved en-route to the ignition circuit itself but the Ignition switch (position 2) also usually supplies the items you mention (as not working) thro' their individual FUSED circuits.
Therefore, your problem may be with the (normally) White wire output from the ignition switch or a White wire in a multi-plug connector immediately down-stream from the ignition switch.
First, eyeball the White wire circuit including the multi-plug for overheating due to overloads in the un-fused parts of the circuit. If there are any burned wires or connections, repair them, but you'll have to locate the short circuit (usually to earth, by a trapped or chaffed live wire) before firing up the repaired wiring/connector.
If wiring is not overheated, flood the ignition switch with switch cleaner or WD40 and likewise the local multi-plug connector. You might also be able to locate the source of the problem by wriggling the local connections mentioned whilst operating the switch.
In the same vein, the problem may alternatively lie with the 12 volt input wire to the ignition switch, usually Brown, again because the other parts of the car that do work OK (dash lights, horn, etc) are not routed thro' or via the ignition switch.
Assuming a conventional ignition switch system. Normally no fuses involved en-route to the ignition circuit itself but the Ignition switch (position 2) also usually supplies the items you mention (as not working) thro' their individual FUSED circuits.
Therefore, your problem may be with the (normally) White wire output from the ignition switch or a White wire in a multi-plug connector immediately down-stream from the ignition switch.
First, eyeball the White wire circuit including the multi-plug for overheating due to overloads in the un-fused parts of the circuit. If there are any burned wires or connections, repair them, but you'll have to locate the short circuit (usually to earth, by a trapped or chaffed live wire) before firing up the repaired wiring/connector.
If wiring is not overheated, flood the ignition switch with switch cleaner or WD40 and likewise the local multi-plug connector. You might also be able to locate the source of the problem by wriggling the local connections mentioned whilst operating the switch.
In the same vein, the problem may alternatively lie with the 12 volt input wire to the ignition switch, usually Brown, again because the other parts of the car that do work OK (dash lights, horn, etc) are not routed thro' or via the ignition switch.
Hi,
Day off tommorow so plan to squeeze behind the dashboard, just to clarifty,
I will first check there is power to the brown wire on the ignition barrell, assuming there is i need to then check the white wire and the white/red wire.
Can somebody tell me the difference between these two wires,
Day off tommorow so plan to squeeze behind the dashboard, just to clarifty,
I will first check there is power to the brown wire on the ignition barrell, assuming there is i need to then check the white wire and the white/red wire.
Can somebody tell me the difference between these two wires,
There is no single 'standard' for the wire colours used but I would expect you to find....
Brown---the main supply into the switch.
White---this will be the ignition switched wire out to the car.
White/red---this will be the starter wire.
Another colour possibly yellow---this will go live if the ignition switch has an auxiliary position but will usually be dead again during start.
Whatever the colours the wires listed here should be the thickest for the first wire in my list and reducing in thickness as you go down the list.
Steve
Brown---the main supply into the switch.
White---this will be the ignition switched wire out to the car.
White/red---this will be the starter wire.
Another colour possibly yellow---this will go live if the ignition switch has an auxiliary position but will usually be dead again during start.
Whatever the colours the wires listed here should be the thickest for the first wire in my list and reducing in thickness as you go down the list.
Steve
So far,
I have a live brown wire at the key barrel
I turn the key and the white wire is then live, the white wire goes to a 10 amp fuse in the fuse box and have a live white at the fuse box when key is turned and the fuse is okay,
Normally when you turn the key to first position the fuel pump starts up and the instruments start working, fuel level, twitch on the tacho, ignition light on etc but getting nothing,
Next please ?
P.S. yes the battery is good, lights, horn all good...
I have a live brown wire at the key barrel
I turn the key and the white wire is then live, the white wire goes to a 10 amp fuse in the fuse box and have a live white at the fuse box when key is turned and the fuse is okay,
Normally when you turn the key to first position the fuel pump starts up and the instruments start working, fuel level, twitch on the tacho, ignition light on etc but getting nothing,
Next please ?
P.S. yes the battery is good, lights, horn all good...
The white wire will probably supply more than one fuse in the fuse box. Have a look along the underside of the fuse box and see if other fuses are linked into the fuse the white goes too.
Steve
ETA This does still not answer why it does not crank. Are you sure you do not have an immobiliser in the system?
Steve
ETA This does still not answer why it does not crank. Are you sure you do not have an immobiliser in the system?
Edited by Steve_D on Saturday 13th April 13:49
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