Thread: What a way to start the day!

Problem solved.

Inertia safety switch under passenger seat was partially tripped... just teetering on the spring. Recently had rear seat passengers (v.unusual) which may help in part to explain why the switch was not fully depressed.

seems like a pretty silly place to locate it - without some kind of protection / shield.

Well fixed. Is that switch in the same place for all RRCs?

I believe so.
It's mounted underneath the passenger seat, at the rear, on the right hand side, about 2 inches in from the rail. You can go by feel, it feels like a little round plastic lump on top of the frame, just in front of the carpet. If you pull it up, you will feel the switch trigger. if you do this, it turns the fuel pump open circuit -

and here is the tricky bit.

Turning on the ignition bypasses this to prime the fuel pump. so there is just barely enough fuel to get the engine to catch, and it will. But as soon as it does, the inertia switch cuts the feed to the pump - which is why you can keep cranking the engine, and it will keep running (because the ignition bypasses the inertia switch to prime the pump - for about 3 sec) until you let go of the key and it stalls again.

Note: There is nothing wrong with the inertia switch itself. It appears that rear seat occupant has moved their feet and pushed it ever-so-slightly, to the point where the spring balance has assisted in opening the circuit - and just enough to not fully engage, which is why the car cut out once on me but immediately started, and why this morning it just happened to not start at all until it was depressed.

Why I did not think to check it, is completely beyond me. I had my mercedes brain on this morning, and not the land rover one obviously. In MB land, the inertia switch is a huge metal-encased gimble mounted auto-resetting switch with a red 6 pin cable connecting to it, and the car wont even give idiot lights if that is disconnected. They also control the SRS / airbags and I've never ever seen one malfunction, unless directly interfered with But that's another story for another time.

Problem solved. Just thinking about building a little protective tube or somesuch around it to prevent it from being kicked up.

Hahahar.... Looks like Oswald is having the last laugh.

get in the car this morning. EXACTLY the same thing happens.

So, I get out, go around to the inertia switch and mess with it, jump back in the drivers seat and.....

not a damn thing.

Behaviour is exactly the same as yesterday. all relays click, pump primes, engine kicks over on crank, but as soon as you let go of the key, it stalls.

So I tried a 'control test' to see what was going on. fitted a testlight in the inertia switch connector to simulate a dummy load, ran a multimeter on the load to check for actual 12v, and cranked it over. As expected, the inertia switch connection is not the culprit.

So the problem still exists without the inertia switch, and while the engine will crank and start, as soon as the key position falls back, the engine stalls.

If you keep cranking to maintain the run condition, there is a point where you can back the key off enough to disengage the starter, but keep the key off the normal 'on' position and the engine will run (idle) normally.

So now, back into the bowels of under-dash electrics I must venture, if only to find out what the bloody hell is going on.


The real question is now: Why did the vehicle start yesterday IMMEDIATELY after the inertia switch was reset to it's correct position?

This has me perplexed. clearly there is something else afoot at the circle-k.

has to be related to the normal 'on' running condition, and a byproduct of either non-contact or intermittent failing contact. (switchover).

Anyone have trouble with their ignition switch ever? i.e. failing in this way? just curious.

Did a bit of forum trawling, came across this from another thread:

Originally Posted by 350RRC

Hi,

The key barrel won't be the problem......... it'll be in the contacts in the ignition switch on the LHS end. The switch can be removed by removing one tiny philips grub screw without undoing the whole lock assembly (which will be an angle grinder job if it is the original and the shear bolts are, well....... sheared).

With a bit of care and nouse you can get the switch apart, re-do the contact dimples etc, for a temporary fix you may get a couple of years out of. The most important things (if you do this) is to make sure that the end of the switch is held firmly in place in its housing (to maintain proper contact inside) and to make absolutely sure that there is no chance of wiring shorts with the binnacle metal mounts.

A whole new lock unit, new keys, etc is only about $180 from here:

eBay Australia Shop - Classic Land Rover Range Rover:

He's on holidays however. You can't buy the switch alone new anywhere.

A faulty (worn) switch will cause all sorts of weird ignition probs, most notably firing while cranking then no spark on run. Don't ask how I know.

cheers, DL

So now I have to ask, How do you know???

It would appear that the ignition switch is contributing to the problem, and further evidence occurred this afternoon.

I went to the car with the explicit intention of simply testing the start procedure.

opened the car, key in ignition, crank *catches* and release the key and it stalls.

second time, I repeat the process, except I hold the key and slowly return it, and it appears that there is a little bit of movement which allows the car to continue running - the key has returned to it's correct run position, but it's done so in a controlled manner, so obviously there is something not quite right with the ignition switch.


Now, question is, where do I find one....

Yep. I'd say ignition switch.
Mine got so bad, the plastic cracked.

Get an OEM or good quality replacement. I got a cheapie that fell apart a few weeks later which resulted in a part of the forest now being referred to as "Mick's Corner".

Interestingly, I have a Merc that has the same problem.

Originally Posted by Mercguy

Did a bit of forum trawling, came across this from another thread:




So now I have to ask, How do you know???

It would appear that the ignition switch is contributing to the problem, and further evidence occurred this afternoon.

I went to the car with the explicit intention of simply testing the start procedure.

opened the car, key in ignition, crank *catches* and release the key and it stalls.

second time, I repeat the process, except I hold the key and slowly return it, and it appears that there is a little bit of movement which allows the car to continue running - the key has returned to it's correct run position, but it's done so in a controlled manner, so obviously there is something not quite right with the ignition switch.


Now, question is, where do I find one....

Hi Merc,

Did read the original post and thought ignition switch but hung back a bit.

When mine really screwed up in the middle of nowwhere it had a couple of other symptoms as well as the basic one you describe. Was lucky to be able to diagnose and hot wire to keep going.

My replacement came from this site:

items - Get great deals on items on eBay Stores!

Was known as CLR or similar, based in NSW, but the principal (Gary) died a year or so ago and it appears that they are just winding down.

The replacement cost was about 130 bucks for the whole switch / barrel assembly and 2 new keys.

cheers, DL

Yeah, my 107 had the ignition switch replaced, I replaced the switch on the 126 and soon it will be the cosworth's turn. Funnily enough, the 124 coupe is perfectly fine...

push button option is sounding like a good alternative too.