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I have engine out and have recently rebult the fuelling side of things (hard fuel lines, accumlator, filter, pump, fuel tank). I would now like to test the fuel pump and fuel sender. So, I dropped in the battery and wire it up.... nothing. Tested at the fuse board and there is zero power. So I follow the positive terminal, wire, under car, up front... and.... and ... its dangling loose. Ah yes I remember, that's the starter motor. I hunted around and I cannot find any other wires coming from the positive terminal, and I finally remembered the engine wiring loom was connected at the starter motor.
Am I correct in thinking this wiring loom plugs in with the 14pin connection and supplies current to the rest of the car, including the fuse board?
Is it ok to connect the loose starter motor wire to the engine wiring loom and plug the 14 pin connector in? And, will that enable power to the fuse board and allow me to start testing some of the auxillary components?
The 14 pin doesn’t carry heavy loads through it, there’s a heavy red wire running back to front that links the battery, starter and alternator. There’s also another red wire from the alternator that feeds the central electrics board via a different connector. You can use that, assuming your ignition switch is working.
Do you have the wiring diagrams?
The 14 pin doesn’t carry heavy loads through it, there’s a heavy red wire running back to front that links the battery, starter and alternator. There’s also another red wire from the alternator that feeds the central electrics board via a different connector.
Do you have the wiring diagrams?
Hi Gazfish,
Yes I have the wiring diagrams, but to be honest I struggle to understand them from a practical point of view... meaning I can see which wire goes where, but how it is on the actual car (where the wires run)
I have the heavy red wire running back to front, joining at the starter. Part of my engine wiring loom has the other heavy red that links starter to alternator. Do you know where abouts on the car the connector is that feeds the CEB?
Power gets to the central electrics from the battery to the starter motor, to the alternator to the hot plug in the engine bay then into the loom that takes power directly in the CEL. Any break in that link chain and no power to the CEL.
You can just connect the Starter B+ connector to the jump post with an ~8 AWG wire (or better). Be careful - insulate the terminals - connect the jump post first - be careful with wrenches - you can do welding with that wire...
You will be missing power to the ABS - but you don't care about that. Dash will be missing ~all the sensors of course & bulb test won't turn off.
You can just connect the Starter B+ connector to the jump post with an ~8 AWG wire (or better). Be careful - insulate the terminals - connect the jump post first - be careful with wrenches - you can do welding with that wire...
You will be missing power to the ABS - but you don't care about that. Dash will be missing ~all the sensors of course & bulb test won't turn off.
Alan
Hi Alan, ah thats useful - Ok, I'll try that and post back
Power gets to the central electrics from the battery to the starter motor, to the alternator to the hot plug in the engine bay then into the loom that takes power directly in the CEL. Any break in that link chain and no power to the CEL.
Thanks Fred, Ok - gonna try what Alan suggested and come back.
I just use a battery jumper cable from the battery cable at the starter, to the jump post. Careful that you have good grip on the jump post, don't want it slipping off and welding itself to the fender as it falls.
I just use a battery jumper cable from the battery cable at the starter, to the jump post. Careful that you have good grip on the jump post, don't want it slipping off and welding itself to the fender as it falls.
Good idea Rob! just saved me buying a thick bit of wire :}
There was an incident with one of our key vendors a few years ago when seemingly nothing was wrong with a S4 left in his premises over night. For whatever reason one of the cables leaving the hot post einner arthed and set fire to the car after burning through the steel inner sidewall- what a mess! Carl was fortunate it did not burn down the entire premises. An interesting discussion ensured about whether it was possible to meaningfully fuse to protect against such an event.
04-18-2022, 12:45 PM
Testing electrics without engine in
