Engine wiring

Having bought a feelander td4 a few years ago had nothing but trouble with it,
It has just had the cluch done but has developed a problem of not starting on further investigation part of the engine harnes has been cut and joined, does the ecu rely on resistance as the joins will change this. the engine turns very slowly too. any help would be great

Sensors will vary their resistance as the physical thing they're sensing changes. So additional resistance in the wiring may put the values the ecu reads out of spec. For eggsample the temp sensor may read correclty, but the ecu will read the additional series wiring resistance you refer to and this will offset the reading. So you'd get a higher or lower temp reading.

thanks for that thought that would be the case looks like time to fit a mew engine loom

If you make some clean connections in your wiring, you could get away with using these:

100 MIXED BUTT CRIMP TERMINAL THROUGH SPLICE CONNECTOR | eBay UK

Use a proper crimp tool too and water proof them afterwards.

If the joints in the harness are good, clean and tight the extra resistance should not make enough difference to affect your car. The only wires that must have almost no resistance are the starter cables and earth, any resistance in these wires will cause your engine to turn over slowly when trying to start it.

Having used heatshrink solder joints on the harness all good would recoment them to a clean waterproof joint in seconds