Not MG related but the general process applies to pretty well all modern cars, I've written this to demonstrate how to go about mounting what the autoelecs call an electrical campaign, this is the systematic approch to finding electrical gremlins that are not imeadiatly obvious!
I went to move the Ford ute in the driveway, it's been sitting for @ 3 months as I've not been able to drive since my stroke.
Well the bugger would wind over but not start, I noticed thatt upon turning the starter key it would crank but not fire, worse was when the key was released the starter motor kept cranking over the engine!
1st port of call was to suspect the starter switch, so stripped off the steering column shrouds and various other bits of plastic shit in the way! The key switch on these things have various pointless pain in the arse security features, like shear screws to prevent removal and the whole assembly is a sealed unit to prevent tampering, the lock barrel is of the Tibbs type to render it unpickable by normal lock picks and an electric lock picking gun also known as a lock vibrator. (These things are great fun, I have one, as well as a comprehensive set of regular lock picks......don't ask!)
Anyway unpluging the key switch from the loom and attacking it with a multimeter showed correct electrical function.
All these and other security measures such as a now disabled immobiliser don't do a thing to prevent car theft, these days your typical scumbag vermin car thief doesn't bother to learn his/her craft (or whatever indeterminate gender they identify as), he/she/it now will steal car by ether using a scanning, cloning device to pop your locks, car jacking or stealing your keys by several methods, such as breaking and entering your home, mugging you, all with the delightful possibly maiming or murdering you in the process.
All these demonstrate the great leap forward the the modern car has over it's predecessors, instead of your older car just getting stolen whist parked unattended somewhere, you now get to be injured or killed by the thieving bastards!
Just the other day some poor young bastard had his hand chopped off in a home invasion in Sydney!
Anyhow back to the reluctant Ford and it's less than enthusiastic attitude to starting...........did a few check specific to these Fords, including an OBD scan (nothing to see there) a check for spark (for this I have and old welding earth clamp with a sparkplug attached, you clamp it to the engine, pull one of the plug leads and stick to onto the plug on the clamp then crank over the engine whist observing the spark. I was getting a healthy spark. Next I needed to determine that the injectors were firing,so I removed one of the injector plugs and fitted a noid light, this is a little LED light that you plug into the injector harness to see if the injector is getting a signal to fire........it wasn't firing the injectors!
Next up check the various relays with a relay tester........nah nothing obvious there but still not making any sense, checked some diodes in the system nothing obvious there either, followed by much poking about with a multimeter didn't get far there!
Now the suspicion was with the wiring loom, did wiggle tests, to do this is trail and error, you systematically work your was along the wiring loom pulling and wiggling it to see if makes any difference...........ran from the ignition switch through to under the bonnet, along to various electrical components in the engine bay back under the dash to the BCM (body control module) and the ECU............ Bingbloodygo! there must be some loom damage buried deep in the dash as a wiggle of the loom leading to the ECU made a difference, the bloody thing started to behave itself logically, mind you by this time the Ute's battery was too flat to start the damned thing.
The dash will have to come out to find exactly where the wiring loom is shorting out.........A big bugger of a job, and the ute's battery is now on the charger having a good feed of volts!
At this juncture we come to the end of the days play.........to be continued!
"Keep calm, relax, focus on the problem & PULL THE BLOODY TRIGGER"
Please Log in or Create an account to join the conversation.
