Hi All

I have a 2003 2.8 jtd Ducato that refuses to start. All was normal and nothing has been done to the vehicle other than sitting for a couple of days.

There is only 7v reaching the starter motor solenoid (the one on the side of the starter) and this is not enough to trip it.

The battery is fully charged and the engine starts fine if 12v is applied to the starter.

It has a Sigma M30 alarm fitted, but we have 'jumped' the connector to isolate this and still no joy.

I can only assume that there is a relay somewhere that is dodgy, but where?

Does anyone know the position of a relay in the starter circuit or anything else that I should be checking?

Many thanks in advance

Val

Hi
I would be checking the battery negative earth "strap" to chassis connection just below the battery on the chassis rail as well as the earth on the top of the starter solenoid, there is possibly a bad connection between the two or both, whether there is another earth connection somewhere I'm not sure but there doesn't seem to anything listed in the eLearn.
Also are you using the 12 Volts from the original battery or are you using a second battery to test the starter, if using a jumper lead from the original battery using a jumper lead & it starts OK, I would also be looking at bad connections &/or fuses on the positive cable amongest the numerous fuses etc on the positive battery terminal connection block. See explanation previous post - https://www.fiatforum.com/ducato/260991-battery-fuse.html
Cheers

Hi

Thanks for the pointers, but I have ruled out both of those.

Using the old fashioned tester, If I place a spanner across from the main positive feed to the starter to the solenoid signal connector, the engine starts perfectly. Just to be certain, I have removed cleaned and re-made the two main earth connections and load tested the battery.

Does anyone have any idea of the circuit that the starter solenoid signal wire takes from the ignition switch to the starter? The fault certainly seems to lie somewhere in this, probably a dirty relay, but could be a connector or even a damaged wire.

Thanks

Val

Very common fault on these, simply fit a 70A relay down by the starter. We normally cable tie them to the radiator fan loom in front of the starter, run the wires to the starter, earth the relay at the D/E of the starter. Takes about 1/2 hr, and will solve your problem. Use 2mm cable for the relay feed and output, .85 - 1mm for the windings.

Hi Arrk

Thanks for the tip.

Do you normally use the existing signal cable to the starter solenoid to trigger the relay, or lay in a new one from the ignition switch? Worried that the reduced voltage will not be enough to trigger the relay.

Thanks

Val

Use the existing wire. The starter solenoid draws in excess of 50A on pull in, whereas a relay is under 200mA. Make sure you use a protected relay ie. one with either resistor or diode protection.