Strange Relay

[deanandeva]

Hi All,

I have this relay and I'm not sure what its purpose is and I'd like to get rid of it. The clue is the car was on gas until recently and I'm thinking it was related to the gas conversion.

Wires are going to:

+VE Alternator/Battery Side (RED)
+VE Side of Coil (RED)
Ground at Firewall (Black)
Yellow (to the Engine Loom (Yellow) I haven't traced where this ends up .

Appreciate your thoughts (I'm guessing take the yellow directly to +ve on coil and se what happens )?

Attachment 15075

[playwme]

I reckon it's probably there to compensate for a voltage drop issue related to the coil.

[hxbunny]

^^^^^^^^^^

Yep, it's for the electronic ignition and is needed for it to work properly.

Cheers

[deanandeva]

Thanks Guys, this is actually a blue motor (painted red) so it has electronic ignition. It seem to have the wrong coil on it anyway.

I am chasing down the proper Transistor coil for the WB Blue motor. Would I still need this relay ?

Thanks for your input

[wbute]

No relay on blue motor electronic ignition. You need to get the genuine coil. Any of the after market ones I have had were rubbish. In the end I bought a few second hand ones from Greg at classic oz wreck. Those GT40 coils are not reliable.
I have no idea why youwould need a relay on a coil. A resistor to reduce the voltage on points maybe?

[playwme]

Voltage through the ignition switch might be a bit low. Bit of automotive VD (voltage drop).

Don't the standard ignition systems run a lower voltage to the coil, and when you upgrade to electronic ignition it's not quite enough? I remember having an issue like that when I put the blue motor in.

[deanandeva]

Guess Ill just try the original coil without the relay and see how we go ?

[JDT]

The electronic ignition that you are running needs 12 volts to operate correctly. HX yellow wire is only about 8 volts. That's why the relay has been fitted. You need an oil filled coil for the HEI system. I managed to score a couple of these coils locally. They're getting a bit hard to come by. Make sure your relay is connected properly. Terminal 30 on the relay should be your 12 volt supply (should have an inline fuse) , Terminal 87 on the relay should go to the positive side of the coil, 85 and 86 are the switch terminals. One should go to earth and the other should have the original yellow wire connected to it.

- - - Updated - - -

You can also get rid of that distributor cap by replacing the cap with a Bosch GB926 and the rotor button with a Bosch GB 786. You'll need to replace all the leads as well. Makes for a much neater engine bay.

[wbute]

You do not need a relay. This link tells you how to get 12 volts out of your original harness. The relay is just a source of problems.
http://www.mysandman.com.au/forums/s...ronic+ignition

[Dr Terry]

The neatest way to carry out the wiring to supply a good 12V to the coil is to bridge the yellow & pink ignition wires at the ignition switch. Remove the relay & its associated wiring & run the yellow wire straight to the coil +ve. You will need to drop the column to gain access to the switch wiring, but it's not a difficult job.

JDT's suggestion of using the smaller cap & leads etc. is a good one, it makes things much neater.

The correct coil to use is the Bosch HEC715 which has a female outlet to suit the older style leads. This coil can also be purchased as IGC-173 at Bursons etc. They are the genuine Bosch replacement for the old oil-filled barrel coil.

Dr Terry