Dual Resistor

by **Trep01** » 26 Nov 2010 21:00

Hi, I'm hooking up the wires in my engine bay (73/Rallye) and have a question regarding the dual resistor on the fire wall. The resistor has one wire from the coil going into the left side and I know there was another wire on the right side as well but can't seem to locate it. Can anyone tell me where the other wire is coming from? It's been about three years sicne I pulled the wires off. I took pictures but still can't locate the other wire. The engine is a 340. Thank you.

by **RedRaven** » 26 Nov 2010 21:21

Im guessing the starter relay, the guys should be on soon to confirm, I have 383 not a 340.

by **dave-r** » 26 Nov 2010 22:39

RedRaven wrote:Im guessing the starter relay, the guys should be on soon to confirm, I have 383 not a 340.

No.

by **dave-r** » 26 Nov 2010 22:40

Trep01 wrote:Hi, I'm hooking up the wires in my engine bay (73/Rallye) and have a question regarding the dual resistor on the fire wall. The resistor has one wire from the coil going into the left side and I know there was another wire on the right side as well but can't seem to locate it. Can anyone tell me where the other wire is coming from? It's been about three years sicne I pulled the wires off. I took pictures but still can't locate the other wire. The engine is a 340. Thank you.

I will post up a diagram for you tomorrow.

by **dave-r** » 27 Nov 2010 15:26

Trep01 wrote:Hi, I'm hooking up the wires in my engine bay (73/Rallye) and have a question regarding the dual resistor on the fire wall. The resistor has one wire from the coil going into the left side and I know there was another wire on the right side as well but can't seem to locate it.

First things first. Take in the next three points.

A coil has a POSITIVE side and a NEGATIVE side. Make sure you know which is which.

From your ignition switch you should have two wires. One dark blue (RUN) and one brown (START).

The dual ballast obviously has two resistors. They are not the same value so you need to make sure you know which one is the 1/2 ohm and which is the 5 ohm. With the slot on the right and the hole on the left the 1/2 ohm resistor is on the top.

The dark blue switch wire and the blue/yellow wire from the ECU should go to one end of the ballast resistor. The end that is linked together and has a slot on the right.

On the upper left of the resistor (the 1/2 ohm) you should have a wire that goes to the +ve of the coil. Probably blue in colour. Could be green/yellow either.

Now your loose brown wire (from IGN Start) has to go to one end of that coil +ve wire. Either end will do so if it looks like it was on the coil +ve terminal you can put it back on there.

The lower left side of the ballast (5 ohm) has the green wire from the ECU connected to it.

The black/yellow wire from the ECU goes to the -ve side of the coil.

This is where this grey wire comes in. I think that wire may be for the tach if you have one. Try to see where it goes. If it is the tach then that also needs to connect to the -ve side of the coil.

Hope that helps.

by **Adrian Worman** » 27 Nov 2010 17:12

If you remember the coil wire going to the l/h side of the resistor it sounds as tho its upside down to Daves nice diagram. If thats the case then the missing wire could be from no.3 ecu connector, whats also likely is that if the ecu is a replacement then it may only have 4pins anyway, that wire is then not required amd can be taped back.

by **dave-r** » 27 Nov 2010 18:30

Adrian Worman wrote:If you remember the coil wire going to the l/h side of the resistor it sounds as tho its upside down to Daves nice diagram. If thats the case then the missing wire could be from no.3 ecu connector, whats also likely is that if the ecu is a replacement then it may only have 4pins anyway, that wire is then not required amd can be taped back.

I have turned the diagram around so the resistor is the way up it should be on the car. Now you can see that the coil wire +ve wire does indeed go to the left of the resistor. :wink:

by **RedRaven** » 27 Nov 2010 19:38

dave-r wrote:
RedRaven wrote:Im guessing the starter relay, the guys should be on soon to confirm, I have 383 not a 340.

No.

I guessed wrong then.... :lol:

Glad I said wait for the lads to confirm...

by **Trep01** » 27 Nov 2010 23:50

Dave, I'll run with it the way you descibed. Thank you for taking the time to help me work through this. You've been a great help. Mark....

by **fbernard** » 28 Nov 2010 18:11

The gray wire with the uninsulated 1/4" female spade terminal could also be the oil pressure sender wire.
It's in that area, it's gray, it has the right terminal.

by **dave-r** » 28 Nov 2010 19:00

fbernard wrote:The gray wire with the uninsulated 1/4" female spade terminal could also be the oil pressure sender wire.
It's in that area, it's gray, it has the right terminal.

That will be it then. :thumbsup:

Re: Dual Resistor

Re: Dual Resistor