Ignition problem on my 150

My 150, with an orig E-type R 3,8 block (and Mk10 cylnhead) needed a new battery. Also got a new neg/earth cable.
Hooked it all up. Ignition on, and everything is normal, but when I pushed the starter button I heard a click, and then everything died.
An hour later nothing happens when I turn the key.
I wonder if the engine bay mounted starter solenoid is the culprit. There is a battery cutboff switch, but nothing can happen to that part!?!?
There is no main fuse as far as I know, just the 5-6 fuses under the black cover plate, but those fuses relate to lamps and horn.
Any ideas of what is going on?
I am most confused. Car has neg earth.

Could be your new battery or new earth lead connections if it was all working befor and nothing else was changed…clean up the earth connections and test the new battery…jump starting with a good battery is a good start…Steve

Battery was charged with my Ctek and is fine. What caused that click, and caused everything to just die? 3 hrs later still no action anywhere with ignition on.
On the first attemt with new battery abmbd ignition on, the lamps and petrolmpump worked as normal
It was pressing the starter button that gave one click and then everyting went dark and silent.

When you press the start button that pulls in the solonoid…this will be the Click you hear…the soloniod operating then connects the battery to the starter motor…if there isnt enough power in the battery to operate the starter then your effectivly shorting out the battery and every thing will go dead…so again was it all working before? …What have you changed?..dont just assume that becaus you charged the new battery with a ctec that its ok…you still need to check it…Steve

What happens when you push the rubber button on the back of the solenoid?
solenoid button
When you do this the engine should crank (turn over). If the key is on the engine may start.
But my first guess is you have a dirty or poor connection at the battery.

do the solenoid button test Rob described. Try a jump from a good battery, then If still nothing…start to reverse some things…first…put the old neg earth cable back on and try it. I have had a bad cable connector that did similar. Nick

Nothing. Tried that early on.
I will get the booster out again, tomorrow morning, and report back.
Thanks sofar.

Skickat från min iPad

Yes it can go flaky, remove it to see if you get power to the starter.

I had last year a bad Ctek loader, the Ctek drains the battery instat of loading.
Everything on de Ctek looked normal.

Are you ABSLUTELY sure it is Neg earth? They were pos earth originally.
I think the solenoid on the starter is the culprit.

Update: tried another battery. No difference. Hooked up the booster and all is normal, but pyshing the starter button gives a few weak turns on the flywheel, then gives up, but still keeps the lamps and pump going, unlike 2vdays ago when pressing the button just killed off everything.
Will check the orig battery which I thiught was old and weak, causing me to change it in the first place.
So we have the battery cut off switch and the fire wall mounted starter solenoid which could cause the severe reduction in power between the battery and the starter….?!
Car was converted to neg earth many years ago. The various cables are thick and just a few years old. The orig style starter was rebuilt a few years ago.


Have you tried to “bypass” the starter solenoid? Connect/clamp a good battery cable to (in your case) the + pole of your battery and touch the starter motor contact with the other end (thereby assuming that the earth connection is still OK). The starter motor should turn immediately… If so, the internal contacts of your starter solenoid are probably corroded.

Bob K.

Thanks. You mean this original starter solenoid?
Have thought about replacing it. Did so on an S-type where pushing the button inide the car did nothing, but pushing the rubber coverrd button on the solenoid in the engine room, worked.
So they can show various faults, these old solenoids

Make sure you have a good connection between the battery and earth (car frame). The started uses a lot of current.
Pat H

And a good earth strap between frame and engine. I remember getting caught out by that one years and years ago on a Mini.

On another occasion the accelerator cable on an MG was acting as the earth to the engine - it glowed when cranking!

In short (no pun intended), I would jump the starter motor directly from a known good battery to make sure it is working, then work backwards through the cables.


I’m still waiting to hear if the isolator (battery cut off) switch has been taken out of the circuit.

In Jags, does all the current go thru the ammeter gauge? If so, wouldn’t hurt to check out the terminals at the gauge.


Hi John…no not all goes through the ammeter and especially not the starter motor…but the ignition and starter button does…Steve

Very grateful for all the assistance, I have not yet removed the battery cut off switch from the circuit. I suspect the next part in the circuit, which is the starter solenoid mounted on the fire wall. I will order a new one.
But I wont be back in my summer house until first week of March, so I cant continue this interesting discussion until then.
It now strikes me that when I thought the battery was getting bad, it was in fact a gradual weakening of the current to power the starter motor…
So whatever the culprit along the way, it was a gradual malfunctioning.
I know and agrre about the importance of the earth cable, but this is brand new. Thich, heavy duty wire with good connectors, so not that I think.