Wiring questions

[jwad355]

Hi,

Can you please explain what the orange wire to the AC does, do I have to connect it? if I do is it just piggy backed off the turn on wire to the compressor?

Can I run the fuel pump power feed to a relay to switch the pump on, instead of directly to it?

Will the tach output be ok to run to a dakota digital dash?

Thanks in Advance

[mike@msd]

It does just tie into the positive coil side of the compressor to see power going to it. It kicks up the IAC counts to keep the idle up and also kicks on fan 1 if it is not already on. If you have a mechanical fan or some other way of turning on the electric fans on, it is not necessary. Most modern compressors do not draw too much HP at idle, but if it is an older style one, you may want the kick up.



The tach should drive the dash just fine. It is just a 12v square wave at 4 pulses per rev (standard 8 cylinder output).

[jwad355]

Cool, thanks for explaining that Mike.

With regards to the fuel pump wiring, is it ok to run the orange wire to turn on a relay rather than directley to the pump + as the instructions state?

[mike@msd]

Yes, absolutely. Just set it up as a regular return system with regulator in that case. A regular relay cannot PWM at all. This is exactly what you have to do with big pumps that draw close to 20amps.