URGENT HELP PLEASE! My E320 Coupe won't start!

[mercboiuk]

I've just spent the day taking off my wheels, cleaning and waxing them front and back. I've also pressure washed the wheel arches and shampoo'ed them by hand.
Nothing wrong there, except when I went to move the car afterwards, the car won't start. The dash lights up fully, and the fuel pump whirls into action, but there's nothing from the engine. Absolutly nout - just silence!
I was doing one wheel/arch at a time and car was unlocked for the duration of the day.
It's a 1995 model with a factory alarm and immobiliser (the passive immobiliser has been by-passed).

I've locked the car several times, leaving a good few minutes between attempting to start her again.
What have I done? Please help!

I know this thread shouldn't strictly be in GD, but I figure this is the forum which people will mostly frequent. If the mods wish to move it, fair enough

Many thanks in advance,

Darren

 

[Dieselman]

Check the 12v and Gnd power leads to the engine from the body and the 12v starter lead to the solenoid.
Try shorting 12v to the small solenoid terminal, that should cause the starter to spin.
Also make sure the gearbox inhibitor switch is working properly.

 

[para alpha]

was the interior lights on while you were washing it? if so try recharging the battery!

 

[mercboiuk]

Thanks guys.

No lights were on, and the battery is about a year old, so I don't think it could be that. I'll may try jump starting her tomorrow though.

The gearbox inhibitor switch is 4 months old, so I don't think it could be that either.

What's this business about the 12v cable and the ground cable? I'm guess I'd be shorting the wires directly connected to the battery.
It may seem a simple for most people, but I'm not "most people" when it comes to undee the bonnet of cars

Darren

 

[Dieselman]

The starter has a big 12v feed and a small 12v feed. If you apply 12v to the small feed it will make the solenoid engage so forcing the starter on.

A spanner jammed across from the large to the small terminals works a treat, but eh spark will make you jump..

 

[Smiley]

I would not jump start if it is not a flat battery; you may do some other damage. It has to be something simple like you have got water in somewhere. How much of a pressure washer was it - a hose or a proper full on pressure thingy?

 

[The G.F.P]

mine does this as i think the immob wont turn off

disconnect battery and wait 30 mins and then try again

30 mins is ott but it works for me every time

 

[mercboiuk]

I would not jump start if it is not a flat battery; you may do some other damage. It has to be something simple like you have got water in somewhere. How much of a pressure washer was it - a hose or a proper full on pressure thingy?

It's a full-on pressure washer, just cleaning my wheel arches of a summer of muck!

I did the same to our '140 CL yesterday, and there were no problems

Darren

 

[imadoofus]

This happens to my Volvo occasionally. With that, I move the shift lever from P to N, and then it starts fine. Inhibitor or something?

 

[talbir]

Lack of engine turning could be a few things :

- dead battery (doubt it in this case)

- immobiliser tripped : a good way to reset is to remove the ground connection on the battery for two minutes and then reconnect

- gear safety switch : may be faulty or going faulty...move gear to 'N' and try to start

- check fuses to see if any fuse is bad....soetimes aftermarket alarms/immobilisers take a feed from a fuse point which when blown means the car won't start. These old fuses need to be inspected closely for corrosion or hairline cracks, sometimes they look fine but aren't



talbir

 

[mercboiuk]

Problem diagnosed....

I tried putting the car in Neutral first (as it was the easiest), and the car started straight away! It didn't start, if put back into Park though.
Gave my Merc specialist a call, and a new gearbox inhibitor switch will be ordered a fitted, hopefully just after the weekend.

Many thanks again, for everyones input here

Darren

 

[nigel cross]

Can you get your lever into neutral?, mine wont move out of park unless the engines running

 

[mercboiuk]

Can you get your lever into neutral?, mine wont move out of park unless the engines running

Yup. If you turn the key to position 1 or 2, you can move the gear lever. Then turn to position 3 to for engine iginition.
That certainly applies to older Mercs - I'm not sure whether the more recent models allow you to do this though....


Darren

 

[Dieselman]

If it works in N but not P then surely the switch is ok but the adjustment is out.

 

[Number_Cruncher]

>>If it works in N but not P then surely the switch is ok but the adjustment is out.

I'm not sure that logic follows DM. It shows the moving contact is OK, but it doesn't allow the fixed contact which makes when in P off the hook.

When my switch failed, you could get it to start by wiggling the gear lever in park, or simply putting it into N.

IMO, this is one of the real design blunders made by MB - the starter inhibitor switch is directly below the AC drain, and gets a regular drenching.

 

[Dieselman]

I've not inspected one so am not sure, but was thinking that the N selection proves the switch itself works so thought it maight be the selection being incorrect in P.
In addition mercboi said his car has recently had a switch.

 

[Number_Cruncher]

>>N selection proves the switch itself works

Yes, it proves *part* of the switch works!

To check the switch alignment is simple enough to do - with the car in neutral, a 4mm rod (about 20 - 25mm long) should pass between the alignment holes on the switch. Getting under there is also a good opportunity to check that the bushes on the shift linkage are in good nick.

 

[Number_Cruncher]

Forgot to say that if the OP strips out the passenger side interior - carpet, centre console carpet, and foot rest the connector block for the inhibitor, and the imobiliser relay can both be accessed.

When mine was playing up, before I realised it was the inhibitor switch, I had these connectors easily accessible, and kept a test lamp with me to test the circuit as and when it failed to start.

From these connections, you can test enough to be sure where the fault lies - ignition switch, alarm/imobiliser, imobiliser relay, or inhibitor switch; leaving only the bulkhead connector in the engine bay and the connection onto the starter solenoid itself unavailable for testing.

 

[coupe deville]

I tried putting the car in Neutral first (as it was the easiest), and the car started straight away! It didn't start, if put back into Park though.
Gave my Merc specialist a call, and a new gearbox inhibitor switch will be ordered a fitted, hopefully just after the weekend.

same thing happened to mine, I jacked it up to get access and then covered the switch and connector with a rag to protect it and then I sprayed the selector rod and lever with wd40 and its been ok since

 

[mercboiuk]

The part has only just arrived, and my car booked in for a "while ya wait" job at my specialist.
BUT......
A couple of times since posting about this, the car has started fine, as it should, in P.....

Darren