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#1 4.2 starter motor wiring

Posted: Sat Sep 28, 2019 9:13 pm
by cooper66

Could someone take a picture of a serie 1 4.2 starting motor electric connection please ? my car is S1 4.2

I have a brand new wiring loom from autospark, I connected the +12V from the batterie and the White/red connected to starter switch. But I don't know where the brown/black has to be connected, I don't have other spade connector. Should be connected on the solenoid ?


Any picture or advise is welcomed :wink:


#2 Re: 4.2 starter motor wiring

Posted: Sat Sep 28, 2019 9:31 pm
by abowie
The starter motor requires a large current. The power lead is approximately 2m long piece of black insulated wire about 12mm in diameter with eyed connectors at each end. It is not supplied in the wiring kits.

It runs from the terminal bar above your alternator control box (or from the under bonnet starter switch if your car has one) along the engine frames to the bottom of the picture frame, across the front of the engine and back along the right side engine frame to the starter motor. It attaches to the 5/16" threaded terminal bolt on the starter.

The red/white wire connects to the large spade terminal on the solenoid. This comes from the ignition switch (or starter button if your car has one) and provides power to engage the solenoid.

#3 Re: 4.2 starter motor wiring

Posted: Sun Sep 29, 2019 8:52 am
by cooper66
Hello Andrew,

Thanks for the explanation, clear for the power lead it's connected and ok !

The red white is well connected also to the right place. So this Brown/black should go elsewhere then, any idea ?

It is the same than the one of ignition light on the speedo.

Thanks in advance

#4 Re: 4.2 starter motor wiring

Posted: Sun Sep 29, 2019 10:37 am
by christopher storey
Pierre : the black and brown lead goes to a single blade, oil pressure activated, switch which is screwed into the oil gallery which runs along the right hand side of the block at the level of the oil filter housing. It is an oddity of the "ignition warning light" on early 4.2 litre E types that it is in fact driven by oil pressure and has nothing to do with ignition or the alternator

As far as the other wires to the solenoid are concerned there are two thin black wires which connect to the terminal of the solenoid which is also connected to the thick black current bearing wire, and as already mentioned, the red/white goes to the other terminal of the solenoid

#5 Re: 4.2 starter motor wiring

Posted: Sun Sep 29, 2019 9:14 pm
by cooper66
Thanks for the explanation Christopher, I have already the Oil pressure indication wire (Wight and brown), so those two wire share the same connection point on the oil pressure sender right ?

#6 Re: 4.2 starter motor wiring

Posted: Mon Sep 30, 2019 12:41 pm
by christopher storey
No, the "ignition warning light " switch is a separate switch - rather like the brake light switch to look at, but with a single terminal rather than two, and it is usually to be found a few cms in front of the oil filter, just to the rear of the right hand front engine mounting

I am trying to post a picture here , but cannot make the "add image" command work

#7 Re: 4.2 starter motor wiring

Posted: Tue Oct 08, 2019 7:16 pm
by cooper66
Thanks for the pictures Christopher :wink: