Re: Sins of the Previous Owners...
Posted: Sun Apr 02, 2017 8:29 pm
We were on our return trip from our Nationals in Echuca, Victoria (Australia) last year and took the inland route home to Brisbane as it is the most direct route. In the middle of nowhere (I'm talking rural bushland in Australia here), and about 1/3 of the way into a 1500km/930mi trip, the thermo-fan switched on and the engine died. We pulled over on the side of the highway and a little multimeter work revealed that despite the ECU having power, it was not booting up. I have a u20 with EFI, installed by the PO.
An ideal roadside workshop. We did come prepared and in convoy. The tarmac was one of the two lanes on this road and we were at the bottom of a hill!
Somehow we had phone signal and a quick phone call to WOLF EMS was made. It was suggested that the 2amp ceramic fuse (no pic but the size of a grain of rice!!) on the circuit board was likely the culprit and the multimeter confirmed this. Tim, a traveller in our group who is now known as MacGyver, connected a blade fuse to two female electrical connectors. He then bent back the crimping tabs on the connectors so they would form prongs. By luck, or MacGyver genius, the dimensions were correct and we set the fuse into the ceramic holder and pressed the blown ceramic fuse in to hold it in place. Some double-sided tape was then used to keep the new fuse firmly in place and voila.
The new fuse
Firmly attached and taped to the memory chips. It actually lasted a few months until I got around to buying new fuses and installing them.
Now to the point of this post - sins of the past: Admittedly, I should have done a full assessment of the wiring in the car when I bought it but to be honest I knew little about EFI when I bought the car in 2011 and it wasn't until 2016 that I was forced to learn because the crank angle sensor broke. Until then it had never been problematic and I didn't touch what wasn't broke.
However on the side of the road in rural New South Wales, while tracing the power cable to the ECU wiring loom, it was discovered that the ECU power was being picked up off the headlight relay! Also the 10-15amp thermofan was also piggybacking onto the headlight relay. There were NO fuses between the relay and ECU. But wait, there is more. The headlight relay was drawing its power from the coil. Not an ideal clean power supply for an ECU at the least. I'm surprised this setup didn't cause a fault sooner but of course it blew in the most isolated area I had driven the car in 6 years. Thank you Mr Murphy! Needless to say I have found numerous other examples of creative, or perhaps lazy wiring. I have since fused the ECU power lead with a quick burn fuse and am about to install a second fuse box that will draw direct from the battery and supply the thermofan, headlights and ECU via their own fused circuits.
I can talk about the suspension, modified valve cover (all the baffling was removed) and shonky camshaft timing another day.....
An ideal roadside workshop. We did come prepared and in convoy. The tarmac was one of the two lanes on this road and we were at the bottom of a hill!
Somehow we had phone signal and a quick phone call to WOLF EMS was made. It was suggested that the 2amp ceramic fuse (no pic but the size of a grain of rice!!) on the circuit board was likely the culprit and the multimeter confirmed this. Tim, a traveller in our group who is now known as MacGyver, connected a blade fuse to two female electrical connectors. He then bent back the crimping tabs on the connectors so they would form prongs. By luck, or MacGyver genius, the dimensions were correct and we set the fuse into the ceramic holder and pressed the blown ceramic fuse in to hold it in place. Some double-sided tape was then used to keep the new fuse firmly in place and voila.
The new fuse
Firmly attached and taped to the memory chips. It actually lasted a few months until I got around to buying new fuses and installing them.
Now to the point of this post - sins of the past: Admittedly, I should have done a full assessment of the wiring in the car when I bought it but to be honest I knew little about EFI when I bought the car in 2011 and it wasn't until 2016 that I was forced to learn because the crank angle sensor broke. Until then it had never been problematic and I didn't touch what wasn't broke.
However on the side of the road in rural New South Wales, while tracing the power cable to the ECU wiring loom, it was discovered that the ECU power was being picked up off the headlight relay! Also the 10-15amp thermofan was also piggybacking onto the headlight relay. There were NO fuses between the relay and ECU. But wait, there is more. The headlight relay was drawing its power from the coil. Not an ideal clean power supply for an ECU at the least. I'm surprised this setup didn't cause a fault sooner but of course it blew in the most isolated area I had driven the car in 6 years. Thank you Mr Murphy! Needless to say I have found numerous other examples of creative, or perhaps lazy wiring. I have since fused the ECU power lead with a quick burn fuse and am about to install a second fuse box that will draw direct from the battery and supply the thermofan, headlights and ECU via their own fused circuits.
I can talk about the suspension, modified valve cover (all the baffling was removed) and shonky camshaft timing another day.....
