Replacing Opus with DLM - wiring & coil help please

[BudgieV8]

This is an 'I'm stuck & have ran out of ideas' type post, so any help would be much appreciated!
I'm removing an Opus dizzy with the silver block behind the coil & replacing it with a dizzy I bought off e-bay which I think is a DLM? - AMP on side of casing.
So far:
The 'amp on side' has 3 pins out - got an adaptor so I now have 2 pins out. I'm told one is coil neg & the other is coil pos. Do these plug straight onto the coil? - & will the Opus coil suffice?
Also, there is another terminal next to the amp on the dizzy. Whats this for?
Where does the 12v feed come from to power the coil - is it a case of finding this feed & plugging it onto the coil pos? (on the Opus I presume it comes from somewhere in the silver block thingy).
Related to the above, will I find a feed on the 'starter' side of the silver block behind the coil? If so, what happens to wiring into & out of the silver block thingy once I fully convert to the DLM?

This may seem I'm rambling, but I've spent the last week fitting the engine & I'm running out of time/patience to get it going.
(In desperation I put the old Opus setup back on last night & the engine fires but wont run, even though it ran before).
Some pics for reference:
New Dizzy with 2-pin adaptor fitted

new dizzy as supplied 3-pin wiring. also shows another terminal next to the amp - whats this for?

another view

existing Opus silver block. left side is stamped 'starter in' with white & white/black wires & right side is plug shown on next picture

[ChrisJC]

The two wires from your new amp are coil -ve and coil +ve. They connect directly to the coil. I don't know which way around.
Coil -ve might also go to the rev counter.
The existing 'silver box' should be completely disconnected.
The coil +ve should also have a +12V supply which comes on when you turn on the ignition (and says on whilst cranking!)
The spade connector on the distributor behind the amp - I have no idea. Maybe for an addition earth, or screen? Ignore it.
The existing coil will possibly work, but really you need the right coil for that amp.
Chris.

[BudgieV8]

found out about the 3/2 wires off the dizzy from another post on here.
Pin no.1 is coil neg, pin 2 not connected via adaptor, pin 3 coil pos.
I'll connect them direct.
Coil 12v pos supply. If I disconnect the silver box totally I presume I will have a 12v supply from the starter which I can run to the coil?
BTW, what is the best coil for this dizzy?

[ChrisJC]

Coil 12v pos supply. If I disconnect the silver box totally I presume I will have a 12v supply from the starter which I can run to the coil?
BTW, what is the best coil for this dizzy?

Not sure about that. The starter usually has a +12 permanent feed direct from the battery, and the cranking signal from the key. There should be a suitable feed to the silver box, the issue is locating which wire it's on. Maybe a test lamp / multimeter?

The best coil is one as fitted to a Rover SD1 / Range Rover with that distributor.

Chris.

[ramon alban]

Hello Budgie, For the record, I think your original OPUS circuit was thus



and you new circuit should be



The latter circuit does not take account of your dizzy having 3 wires and an extra spade terminal. Features of a dizzy I am not familiar with.

# White/Black is deffo coil negative

# The extra terminal looks like an earth

# And one of the other wires goes to coil positive.

# Your coil needs to be a stock RV8 12 volt unit - so the original 9 volt OPUS coil will not be OK.

[DEVONMAN]

Sorry typed this the same time as previous post so maybe you need to ignore what I have said.
The silver box is a ballast resistor and it also has a resistor in series with the wire to the rev counter. The original coil is therfore suited to a ballast resistor installation and should not be used with your new dizzy.

So disconnect the silver box.
In the original plug that went into the silver box from the car loom, find the wire ( probably white)that is 12v with the ignition on and connect this to the +ve connection on the new dizzy amp and +ve on the new coil.
Connect the -ve coil terminal to the -ve on the dizzy amp.
Again, in the original plug that went into the silver box from the car loom. the black/white wire goes to the tach and this should be connected to the coil -ve to make the tach work.

Regards Denis

[DaveEFI]

new dizzy as supplied 3-pin wiring. also shows another terminal next to the amp - whats this for?

The colours shown in that new loom appear to be green/white and blue/red?

Going by the BS for wiring colours, green/white is left hand flasher, blue/red headlight dipped beam.

The correct colours should be white and white/black.

Was there not a wiring diagram supplied with that new dizzy? Would be interested to know what the extra terminal is. I'd guess a ground - same as the body.

[BudgieV8]

sorry, just posted that to show how it came (with no instructions). That section of wires is not being used as I have a 3 to 2 pin adaptor.

[BudgieV8]

OK, back from the garage.
Connected as per Ramon/Denis's instructions.

Pin 1 on dizzy to coil neg
Pin 3 on dizzy to coil pos (via 3 to 2 pin adaptor)
- (Coil is actually a DLB198 so it seems I've been running the Opus on the wrong coil).
Silver box disconnected.
This is now the situation ('connector' is the connector that goes into the silver box on the left side of my pic):
Plugged top wire (thickest, white & yellow) on connector into coil pos. Has bright light on my tester & turns on/off with ign. spark at plug when starter on. engine fires but wont run.
Plugged middle wire (thinner, white) of above connector into coil poss. Bright light when ign light is on, goes dim when turning over. Engine wont fire up.
(bottom wire has no power - as Denis says its for a tacho).

Have I wired something wrong or is my coil knackered?
- I only have access to a basic tester light

- additional thoughts/info. When wired through the silver block, the top thicker white/yellow went to coil pos, & the middle thinner white wire went to the red wire into the opus

[ChrisJC]

So it seems you are getting a spark whilst cranking? If the test lamp (between coil +ve and chassis) is on whilst cranking and with ignition on, I would say your problem is somewhere else....

How sure are you on ignition timing / fuelling etc ?

Chris.

[DEVONMAN]

OK, back from the garage.
Connected as per Ramon/Denis's instructions.

Pin 1 on dizzy to coil neg
Pin 3 on dizzy to coil pos (via 3 to 2 pin adaptor)
- (Coil is actually a DLB198 so it seems I've been running the Opus on the wrong coil).
Silver box disconnected.
This is now the situation ('connector' is the connector that goes into the silver box on the left side of my pic):
Plugged top wire (thickest, white & yellow) on connector into coil pos. Has bright light on my tester & turns on/off with ign. spark at plug when starter on. engine fires but wont run.
Plugged middle wire (thinner, white) of above connector into coil poss. Bright light when ign light is on, goes dim when turning over. Engine wont fire up.
(bottom wire has no power - as Denis says its for a tacho).

Have I wired something wrong or is my coil knackered?
- I only have access to a basic tester light

The white /yellow should only go live when the starter is turning so don't use it. It's the white that should be connected to the Coil +ve and the amp positive. The coil negative goes to the amp negative.
Sorry don't know the correct coil type for the dizzy amp but there was a thread on here recently which gave the type. Regards Denis

[BudgieV8]

fuelling is ok. Have had the dizzy out to check I'm not 180 degrees out but I'm off to check again

[BudgieV8]

THANKYOU, THANKYOU ALL!!!!!
Swapped the coil for another scuffy thing lying around & ITS ALIVE!
V8 at high revs sounds beautiful to me (but I don't think the street party lot are too impressed!)


For anyone else in the same predicament info on Opus to (this type) DLM is:

Get dizzy & 3 to 2 pin adaptor.
Connect pin 1 to coil neg
Connect pin 3 to coil pos
(OR if you have the adaptor the 2 pins are set as a letter T. top of T is coil neg, downward leg of T is coil pos)
Middle white wire of Opus silver block connector to coil pos
GO!

[ChrisJC]

Good work - well done!

Chris.