Renault clio diesel non start - Robin the Technician
A friend has a 'N' reg diesel with 200,000 miles on the clock. It starts faultlessly every morning and evening for the trip to/from work - a journey of 65 miles each way. However, if she stops and tries to re-start it will not even turn over - no clicking - nothing. If you let itstand and cool down it will start without any problems. I've asked her to check when she gets home to put the lights on and try turning it over to ascertain if its a battery problem - which I don't think it is.
Anyone out there any ideas as to what the problem is??

As always your help is appreciated

These are the views of Robin the Technician with 35 years in the trade. I fix, therefore I am...
Renault clio diesel non start - 659FBE
This problem is almost certainly due to a high resistance somewhere in the starter solenoid circuit. The reason it all becomes critical as you describe is due to engine soak-back heat raising the resistance of the starter solenoid coil. Obviously the present high ambient temperatures don't help. Some starters are very marginal in this respect, particularly if the ignition switch is poor or if there is a long wiring run to it. Remember that it is ampere-turns in the solenoid coil which produce the engagement force; the number of turns is fixed, and the current decreases when everything gets hot.

Checking for this is easy. When you have the problem, bridge directly from the starter main terminal to the smaller solenoid terminal with a short lead. Make sure that you have identified the terminals correctly, and observe all sensible precautions when cranking the engine in this way.

If the starter now operates, the easiest fix on a vehicle of this age is to fit a relay, energised from the lead which went to the solenoid terminal. Use thick leads in the switching side. French cars have notoriously poor ignition switches - maybe the starter swich is high resistance, but the addition of a relay would provide a cheap cure.



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