have i goosed it ?

[tjamesbo]

Round at the girlfriends helping clearing out the garage and came across one of those little motors for turning and starting model aeroplane engines old but obviously never used can we sell it she asks i look it up yep maybe get £10 on facebook marketplace ( she needs the money ) I decide to test it on a 12v battery on my vito i cant get at the terminals as its all under the seat so i try it on her 2004 fiesta battery thinking should be ok it works after a 5 second spin up after this i worry could i have damaged the electrics so i start the car just to check alls fine and it starts .......................... that was yesterday morning today i go to move it and it spins on the starter nothing no cough or splutter no fuel or no spark one of the two after 4 attempts to start i plug my basic obd reader in no codes at all ( and i can hear the fuel pump priming ) so looks like a recovery to the local ford specialist but im worried that its too coincidental and that ive buggered it so is this likely or not ?
i feel guilty as hell and will have to pay for the repair if its associated with my test i just hope it isnt the ECU etc she needs the car for work any longer than a day and its a big problem
any one had a similar experience must have used less current than a jump start but the car wasnt runnng when i connected it how robust are the electrics on one of these ?
Boyd

 

[Ted]

99.9% coincidence I would say.
Disconnecting a running motor would cause a voltage spike but I would expect to see that spike across the motor windings, not the battery terminals.
I could be wrong. I was once. 1967 I think it was.

 

[geoffus]

Coincidence, any "spike" would be absorbed by the vehicle battery, but I very much doubt you can create a spike anyway.
Plus the fact it started directly after the model motor was first disconnected.

 

[DSM10000]

As above.

The load from the motor would have been very small

You said "no fuel or no spark". Have you checked for a spark by pulling a plug lead or does it have cool packs (if so singles or 4 in one unit?)

If all in one is there a fuse /relay that supplies this?

You could carefully crack open a fuel line and see if there is fuel pressure or remove a plug after cranking and see if is wet with fuel.