BUGGER; Electrical gremlin shuts off engine

[GURU]

I have a electrical problem with a 79 series ute when i turn head lights H/B indicators or wipers on the engine stops
any ideas would be appreciated
Cheers

 

[ren]

My guess would be a bad earth somewhere (check all {body engine transmission} earth cables as well as connections for security and corrosion) that could cause a voltage drop when those items are turned on thus affecting something essential for the engine such as an ecu or a pump or sensor reading. If you say what engine you have someone may have some other ideas or experience of the same situation. I had a bad earth on my truck from a bodge by a PO that caused weird stuff to happen. Also check condition of battery terminals and connectors too as there could be a voltage drop there if poor and a significant current drawn. I would have expected Low or Dip beam to cause the issue as well as high beam though but maybe they are dim and not drawing much because of a poor connection as dip beam should be drawing more than indicators.

 

[Shayne]

A bad earth can cause electrical problems even NASA couldn't explain . Rear lights and tow socket are the usual suspects if corroded .

 

[GURU]

Thanks guys im in the process of elimination have disconnected the wiring loom for the tail lights mid vehicle removed headlight and indicator switches off steering wheel no obvious signs of any problems their.
The motor is a 1HD-FTE my next en-devour is the fuse box removal to check that earth point and wiring and engine bay earths
thanks again.

 

[AdventureWagon]

Would say earths here causing the ECU earth (or earth of anything critical connected to it, like a sensor's earth) to float and cause the ECU to shut down. Definitely look at the chassis and block earths and failing that monitor the ECU earths and associated earths whilst you use the devices concerned.

 

[AdventureWagon]

A bad earth can cause electrical problems even NASA couldn't explain . Rear lights and tow socket are the usual suspects if corroded .

This! I spent the first half day of a camping trip using every swear word known to man to solve a trailer lights problem only to find out it was a crap earth. Different lights coming on for different things, and the worst thing of all you use a digital multimeter and it all looks golden!

 

[ren]

I kept getting wappy lighting issues when towing and traced the wiring of the towing electrics to a bundle covered with tape. I peeled the tape off and the nice fat towing earth was connected to a dead skinny earth cable that went who knows where. Although the connection had been decently made the increased resistance of the inappropriately skinny cable was causing a voltage drop. The daft thing was there was a bolt with a decent body earth inches away that they hadn't used. I just disconnected towing earth cable and put a ring crimp terminal on it and bolted it down on the existing body earth. No problems since.