480 ES won't start - instrument panel goes crazy

[whitepk]

Apologies for the title description but it's the only way I can think of describing the problem. I've had a 1994 480ES auto for a few months now. It's been stored under a carport and used on occasionally. I took it for a run the other weekend, did a 24 mile round trip, and it performed flawlessly. I left the car outside for a couple of hours and then had a problem when I started it up again. It started fine but then stalled when I put it in reverse (it's an automatic). I tried it again and it had trouble starting and would only start when I put my foot on the accelerator and would then die. I left it and tried again later and this was when things got very strange. The first time I tried to start it I hear a whirring noise from behind the instrument panel and the instrument lights and gauges went mad - flashing, etc. The next time I tried it the whirring was replaced by a very fast clicking and the same flashing of lights and oscillating of needings (rev counter, etc.) on the display. Any help would be appreciated. Many thanks.

[glasgowjim]

First thing to do ......

Check battery and recharge if necessary .
If you dont have a battery tester or multimeter. then recharge battery anyway.

if your battery is in need of a charge then the current gauge (ammeter0 will read close to 6 A and stay there for a good while .

this sounds like the classic flat battery syndrome that 480 's have.

[whitepk]

Thanks Glasgowjim. Will give it a try and get back to you.

[whitepk]

I checked the battery and it was a little low, so I recharged it overnight. Tried again this morning and no luck. The engine turns over but does not start. As soon as I turn the ignition on a rapid clicking sound (perhaps a relay switching back and forth very fast?) comes from behind the stereo/heater control section of the dash. Any ideas? Thanks.

[glasgowjim]

this still sounds like a duff battery however as its an auto it could be something else !

have to hand this one onto the auto - owners.

[whitepk]

Thanks glasgowjim. Much appreciated.

[Robou]

The rattling sound, indeed probably a relay activating and deactivating, points at a lousy battery, as stated above. The voltage over a battery is not decisive, it also should deliver current. One or more of the six cells inside could very well be at its nominal voltage at zero load, but due to an internal resistance not capable of delivering or even transporting any current.
At a certain low load the voltage will drop below the needed value and an activated relay, by itself responsible for the extra load, will fall off. Then the voltage will rise, the relay becomes activated again, causes a voltage drop etc.
Trying to charge a battery in this condition will not help, it simply will not let any significant current pass through. Moreover, when the charging device does not cut off at roughly 15 Volts and the battery is connected to the car electronics there is a danger of overvoltage blowing your precious equipment.
So get yourself another battery and good luck.

[whitepk]

Thanks Robou - I'll go get a new battery!

[Ulrika480]

Just hijacking the thread -anyone have any battery recommendations for same car - a 2.0 ?
I think mine is knackered as well.

[Ulrika480]

If anyone is interested - just picked up and fitted a Bosch silver battery with 4 year warranty from Eurocarparts.
If you click and collect on-line and enter 'Battery 15' and it comes in at £54.01. (15% off)

Seems like a fair deal for a quality battery.

[volviz]

recheck also ground wire conections..cause bad contact makes same simptoms

[whitepk]

Hi Everyone,

I've bought a new battery but no luck, I'm afraid. Same symptoms - with the clicking/whirring sound behind the dash. I recently checked over the earth connections but will do this again to be sure. Any other ideas?

Thanks

P

[glasgowjim]

Right back to basics on this one.

there is a fuse and a relay (actually 2 if you have no aircon) under the dashboard one is for the ignition and one is for the fuel pump they are located in a RHD car under the dashboard but right up in the top right hand side. To see it you need to lie under the dash with head in drivers footwell. if the clicking noise is coming from one of these if you put a finger on the clicking rwelay you will feel it vibrating . io cana supply replacement ones of these no problem if you need it the fuse holder is clipped either on the back or top of relay.

Next try hot wiring the starter motor. Do a search on " stone age technology " to find the thread (s) .

Turn the ignition key to the on position and turn the starter motor over by a direct connection to the battery it should turn over and the engine start up.

The engine earth is very important if thats not good your car will never start.

[whitepk]

Thanks Jim. Will try that tomorrow when it gets light! Just for clarification the starter motor is working and the engine is turning over. A have a second EOL 480, so if I need to replace the relay I should have a spare.

[glasgowjim]

Here is a picture of the relays ..

[whitepk]

Hi All,

I located the relay that was clicking - it was one of those that Glasgowjim pointed out. I held it and it was the one that was vibrating. I replaced it today with a brand new one to no avail - it's still clicking and the car turns over but will not start. Any more ideas anyone?

Very grateful for all your help.

Patrick

[glasgowjim]

right now you have located he fault , something is switching it on and off so ...

1remove relay bridge the ignition connection and start car if the rest of car circuit is ok then you now know where to check back from.

[whitepk]

Just to let everyone know that my 480 starts fine now. It was an earth in the end (I should have checked more carefully). The wire was attached but had a break in it. Thanks to everybody for their help.

Patrick

[Ulrika480]

Whereabouts was the earth issue on your car ? - I'll be starting on a similar fault finding tour of mine soon!

[whitepk]

There's an earth that attaches to a metal plate sticking up from the engine on the drivers side. It sticks up above the rocker cover.