12 replies to this topic

[minisilverbullet]

I am running a Specialist components 16v headed 1380 engine,

 

Still using the SPI relay bode, so hopefully the SPI guys can still help on this. 

 

 

The battery drains after 1-2 days. Yesterday aI placed a multimeter between the negative cable and terminal on the battery and set it to amps. I could see around 1 amp on the meter. 

 

I pulled each fuse one by one to see which one would stop the drain. It turned out to be a fuse on the SC loom. I roughly traced these wires to the relay box. 

 

I pulled the larger terminal out and this also stopped the drain. So I guess the culprit relates to a circuit from the relay box. 

 

How to I test which? 

[Hamstein]

You can open the relay box and check the contacts on the relays inside (if you've not already done this!) Might get you a bit further in tracking it down.

[minisilverbullet]

is there a method to test current going through a wire? 

[xrocketengineer]

When I had problems with my ECU, I found out that it was a relay since the relay box was warm to the touch after sitting overnight. I borrowed some pins from wife's sewing and inserted them between the wire insulation and the weather seal of the relay box connectors and pushed the pins in until they made contact with the terminal inside. With the connector mated, I could use my VOM to check the functions. I found out that ECU would leave the main relay active forever after starting the car. If the battery, or the relay connectors were disconnected momentarily the problem would go away. Until the next start up.

[Hamstein]

You can get  a 'current clamp', which you clip over the wire, plugs into a voltmeter to give a reading. or cut the wires and use an ammeter for the invasive approach,

 

It's probly better to just find out which connections are getting power on them in the fault situation, the relay box comes apart fairly easily ( at least mine did! )

Edited by Hamstein, 01 September 2016 - 05:48 PM.

[Hamstein]

Oh, I'm assuming relay box is standard , not part of the sc loom

[minisilverbullet]

So working from this diagram from flyingscot

 

 

Both of the main switched live on my relay box are live. 

 

The top left is now a thick brown wire, so I am guessing this one actually should be. 

 

The lower right one however is white which leads me to believe it should be switched live. 

[minisilverbullet]

Oh, I'm assuming relay box is standard , not part of the sc loom

yip box is standard

[Hamstein]

Its a bit dark here for me to go out and poke at my relay box, but this post is useful -

http://www.theminiforum.co.uk/forums/topic/46558-spi-relay-pack-functionality/ 

Mind , you probably got FS's pic from this? Might help anyone else watching anyway!

[Spiffingly Good]

I had a similar problem once on a spi drawing 1 amp, turned out to be the relay for the Lambda preheater stuck on.  Worth a look, just disconnect the lambda probe and see if the draw disappears.

[minisilverbullet]

I have just come in from the garage after a couple of hours tracing wires. Wish I had seen the post above before. 

 

Yip it is the Lambda sensor heater which is the drain. However I don't think it is the issue directly. 

 

So from the relay box the lambda sensor heater and the white ignition wire are permanent live. As i now understand both these should ignition live. So the issue is the ignition source into the the relay box. Obviously this is permanenet live and thus triggering the relays, thus switching/providing 12v to  the white wire and the lambda wire.

 

On the really there are 3 thicker brown wires which at the moment are permanent live, I guess this should not be the case? These wires run to the starter and to a ring terminal which i connected to stud where the battery also connects to.

 

I guess my problem is that this brown ring terminal should be switched live?

[minisilverbullet]

Some info I found by Sprocket regarding the relay module - 

 

"Main switched power supply (large connector)

All four relays are fed with 12v from the battery (brown). Main relay switched live is brown with pink. Fuel pump switched live is brown with slate(grey). Manifold heater switched live is brown with blue. Starter switched live is brown with red."

 

​So it seems like the Brown wires to the relay need to be Switched live? 

[Spiffingly Good]

I found my problem was the yellow relay on the bulkhead, can't remember which one it was exactly, but it's one of the pair of yellow ones.  Basically it was stuck on the latch closed position providing power to the preheater, confirmed by switching the two relays around.