1850HL IGNITION SYSTEM

[bess]

The car has not been run since end Sept. Fully garaged. Fully charged battery, switched ignition on - no ignition light came on. Rotated key to start position so engine began to turn over - car turned over fine and engine fired up. Released key and engine stopped. If key is rotated and held engine will run for a few seconds. Does anyone have any idea what problem might be and how I can put it right? Thanks very much. Brian

[Dolly-Nut]

I expect you have a ballasted ignition coil in which case when the key is in the starting position the coil is fed from the starter, as soon as the key is released the ignition switch should be providing the current but probably isn't. To check if it is at fault run a wire from the positive battery terminal to the input side of the ballast resistor (if you can find it). If you can't find it put the other end of the wire on the positive side of the coil. If it runs don't run it for long (minute or so) because the coil will overheat.

[bess]

Thanks Dan. Will give that a go tomorrow and let you know the outcome. Happy Christmas. Brian

[Carledo]

This description fits perfectly with ballast resistor failure, the engine will run while the key is held in the start position cos of the bypass 12v lead to the coil from the starter. But the lack of an ignition light points to a fault further up the line, possibly in the ignition switch itself or its asociated loom.

Steve

[Jon Tilson]

Sounds like you need a new ignition switch to me.
As I've lots count how many times I've posted about ballast resistors I wont bother saying again
that on later dollies the resistor is built into the loom...

Shorting the whole ignitiion switch out by running a lead from battery plus to coil plus for a short while will indeed confrm the diagnisis as Dan says...

Jonners

[Jon Tilson]

Sounds like you need a new ignition switch to me.
As I've lots count how many times I've posted about ballast resistors I wont bother saying again
that on later dollies the resistor is built into the loom...

Shorting the whole ignitiion switch out by running a lead from battery plus to coil plus for a short while will indeed confrm the diagnisis as Dan says...

Jonners

[MIG Wielder]

Hi Brian, Sorry I've replied a bit late, but it would be nice to find the root cause. When you say the IGN light doesn't come on when the key is turned , do the OIL, & BRAKE, lights also fail to light ? If so there is a common thread here. Can you trace out the high current Brown cable all the way from the connector block on the positive battery lead. Depending which model you have it would be worth checking both halves of the connector in the drivers side footwell. Do you have 12 V here as well.
And with the Ignition switch in the ON position do you still have windscreen wipers and the heater blower motor ?
The test link wire will get the ignition circuits running ( and the rest ) but won't find the cause.
Yes it may be the ignition switch itself but check the brown input wire and the White output wires for 12V power as well.
Good Luck sorting it,
Tony.

[Carledo]

Sounds like you need a new ignition switch to me.
As I've lots count how many times I've posted about ballast resistors I wont bother saying again
that on later dollies the resistor is built into the loom...

Shorting the whole ignitiion switch out by running a lead from battery plus to coil plus for a short while will indeed confrm the diagnisis as Dan says...

Jonners

Jon, I KNOW the ballast is in the loom, that doesn't mean it CAN'T fail! But from the gentlemans symptoms ie no ignition light I would suggest (as you did) that the fault lies not in the ballast itself but in the ignition switch or somewhere very near it!
There must be feed to the switch or the engine would not turn over, so the brown is ok, start by removing the column cowl and check for feed at the WHITE outputs from the switch (may be 2 of them on the same tag or only 1 that splits into 2 at a lower point) with the ignition in the ON position no feed here means a duff switch, (be sure to check at the wire as well as the tag since a dry joint could be responsible)
If feed is established here then you need to follow the white wires until you find where the feed stops and fix as appropriate, it is most likely to be a bad connection in a junction block if its not the switch.

Steve

[TomWard]

Sorry for the bump.
I had the exact same symptoms; for future reference:
After trying the suggestions above, swapping ignition switches, coils etc - 4 hours later, it turned out to be the alternator connector that was not fully engaged.
(Yesterday I had been re-attaching a (what I think is a capacitor, blue cylinder) wire to the thickest brown wire on the alternators connector (via yellow wire tap connector).