Jump to content

Do I need a separate "main relay" for the Link wiring?


Adoom

Recommended Posts

I'm installing a link in a 1971 Triumph to run a 1uzfe.

The original body wiring loom had a total of 3 fuses and only one relay, for the horn. The headlights had no fuse or relay, that poor little switch....

I have now upgraded it so it has a larger fusebox and some relays to protect the switches:

  • Start signal relay. Goes to starter solenoid. This can be the "Start signal" for the Link too?
  • Live with ignition relay. Indicators, heater, wipers, instruments, radio.
  • headlights high beam relay.
  • headlights low beam relay.
  • Horn relay.

I'll have some more relays for the engine:

  • fuel pump relay
  • Ignition Coils relay
  • Engine fan relay

 

So finally on to my question.... Do I need a separate "Main relay" (Like in the "power supplies" section of the Link Help), or can I use the existing "Live with ignition relay" that supplies the indicators/heater/wipers/instruments/radio? 

 

 

Link to comment
Share on other sites

ECU power should come from the same supply as the injectors so it knows injector voltage and can appluy the correct deadtime.

If you want to use the factory 6 wire stepper motor idle valve then you will need the full "ECU Hold power" circuit as per the help file.  This is because the ecu needs to stay powered up for a short time after the ignition is switched off to allow the stepper motor to reset to home position for the next start up.  

If you have changed to a 2 wire solenoid idle valve then you just need something that supplies power to the ecu and injectors when the ign switch is on.  

Link to comment
Share on other sites

10 minutes ago, Adamw said:

ECU power should come from the same supply as the injectors so it knows injector voltage and can appluy the correct deadtime.

If you have changed to a 2 wire solenoid idle valve then you just need something that supplies power to the ecu and injectors when the ign switch is on.  

I have indeed changed to a solenoid idle valve.

So that sounds like a "Yes". The ECU and injectors can share the same relay as the Indicators, heater, wipers, instruments and radio because it supplies power when the ignition switch is on....

Link to comment
Share on other sites

23 minutes ago, Adamw said:

Just make sure it is an ign circuit and not ACC.  Radio, wipers and heater are normally connected to ACC which switches off when cranking. 

Thanks. I hadn't thought of that, I'll go check.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...