Intermitant no start - Red Green lights.

[kiwi_bloke]

My fathers 96 E230 has been sitting for 6 months with the battery disconected. We reconected the battery and it cranks and cranks and wont start. We get alternate red and green lights on the mirror. How ever.


Last night it started fine, 10, 20, 30 times. Was running rough - low Idle but other wise fine.

Tried this morning and no go...just cranks.

Heres what I've found.

If I take the cover off of the main computers (under the bonnet - theres 3 of them plus one relay unit) and jiggle wires I get a whole lot of relays clicking.

At times I can hear the engine electrics fire up. But not the fuel pump.

If i jiggle the wires going into the relay unit (has k2 on it) I can hear the engine electrics cut in and out. But no fuel pump still.

The fuel pump will fire up randomly, IE Ive turned the key on, no pump, off then on twice and the fuel pump will run. But On other occasions the car will start first time, and cut out 10 seconds later and not restart.

If I take the cover off the relay block called K2 and manually switch the relay second from the right, all engine electrics cut in including the fuel pump. The car will run flawlesly every time. Does this mean the relay is faulty? Also in doing this there are no flashing lights.

Notibly some times, I when the car wont start, I can hear relays flicking very fast in the vicinity of the K2 relay.

Any help would be much appreciated.

[Matt L]

Regardless of the plastic housing markings, I believe that you're talking about the K40 relay module. It's at the very front of the box, with several fuses and five or six wire connectors.

It is likely at fault. I resoldered mine. Your mileage may vary.

[kiwi_bloke]

Yes thats the one. Front most, Four 15 Amp fuses on the top of it. And 5 connectors (i think).

Did you just resolder all the conections on the board?

[Matt L]

I did. You will need a high-wattage iron for the heavy connections (bus bars and relay contacts). I used a 180 watt butane-powered iron. My 45 watt electric iron wasn't even thinking about getting the job done.

After fixing all of the heavy connections, fix the small ones. They won't be cracked, but the parts will move around when you solder the heavy connections and if you don't resolder the small ones, they will break later. They did for me.

I removed all of the old solder with solder wick, and replaced it with new eutectic (63/37) solder. I wasn't comfortable just reflowing the connections.

[kiwi_bloke]

I tried soldering up the joints but still no go.

So I thought, Ill get a 12 V battery and directly trigger each relay (power accross the coil)

Every one triggers except the 2 right most - the fuel pump and engine management I believe.

It appears the coils are burnt out.

Im going to put it back in the car today, and verify that there is voltage at the coil when in the car and wheather they switch.

If there is voltage and no switching Ill just get a new one. $NZ 250.

[kiwi_bloke]

Replaced the K40 relay and bang. Fixed.

But now we have a niggling SRS light.

It wasn't on untill we put the new relay in.

I have turned the key on with the relay not plugged in, and one of the computers. I had a senior moment - yes they do happen even when your 22.

If it is because of this will the code reset over time ?

96 e230 - ex japan.