Perfect. This is exactly what I was looking for. I'll report it to Arron at MSA.

So I guess I'll need to know what we can do about it..... Any suggestions?

I'm thinking finding the correct wire and connecting it to an RPM switch? Or directly to the Ignition? Or to the Oil pressure switch on the block?

What do you guys got for people who will want to keep their fuel pump relay plugged in?

Dave

So does anyone have the Wiring diagram for the 73' or know what color the Fuel pump relay wire is that goes to the VR? This is what I really need.

Also, Who has a good link for an "Oil pressure switch" or " RPM sense switch" to activate and shut off the relay in sync with a running or non-running motor?

Please and THANK YOU,

Dave

On my car the wire from the alt/reg to relay A is yellow. If you remember my starter solenoid black/yellow mystery wire...that goes to relay B.

Yellow it is.

Does it need a (-) or (+) signal to turn the relay on?

Thanks Mike.

Dave

If I knew more about electricity I might be able to answer that

The supplement just states that relay A supplies current to relay B and relay B supplies current to the fuel pump.

Here is the best 73 wiring diagram I have, but it does not include the fuel pump harness unfortunately.

73 Wiring Diagram 240Z.pdf

Dave:

I have a 73 with 5/73 build date. Automatic and no electric fuel pump installed. I just installed the ZX Alternator and ZXP 3 weeks ago and have been driving daily with zero problems. Now this thread has probably just jinxed me!

One thing that came to mind were the modifications that may or may not have been made to 1973 models with the V-3 program. I don't know if this could have any bearing on the issue but thought I would at least mention it.

Dave...if you have the answer you were looking for I'd like to see if anyone who has the v3 relays and bypassed them can tell how they did it. I checked relay A on my car today and it was very hot.

  240ZMan said:

Here is the best 73 wiring diagram I have, but it does not include the fuel pump harness unfortunately.

That's because it isn't a 73 wiring diagram.

The one you posted is the "Basic Model S30 for U.S.A." wiring diagram, which means there isn't a fuel pump relay, just the wiring for it.

FWIW

E

Dave,

I have a '73 with the ZXP and 60 amp Bosch alternator. Also have both of your wiring harnesses (HLH and PLH), all installed at the same time.

A while ago I posted that my ammeter was swinging wildly at idle and was charging at about 40 amps most of the time when engine speed was above idle. With lights and fan on the ammeter was pegged.

Since the car is on a Battery Tender most of the time and otherwise runs great, I ignored this until recently when I realized that I no longer heard the electric fuel pump clicking when I turned on the ignition.

A reputable auto electric tech checked the system and told me that the battery was discharged from what he suspects is a battery drain. Alternator was working fine. I noticed that the ZXP seems to have partially melted at the top.

Any ideas about what to do next?

Peter

After much deliberation of the subject, The best coarse of action includes 1 of a few options.

The link below is one post be Steve that he did to his 73' 240Z. He basically tracked the hot wire to the relay connector, cut the yellow wire and ran an ignitioon controlled switch on the wire to make sure that the power gets shut off with the key and it can also be used as an anti-theft switch as well, once his manual fuel pump is eliminated.

http://www.classiczcars.com/forums/showpost.php?p=348665&postcount=7

Some other owners have suggested an oil pressure switch to make and break the connection of the yellow wire. No Oil pressure due to a non running motor means no fuel pump running. The switches are available at most auto parts stores and online at www.Jegs.com and www.Summitracing.com.

Some others just suggest a simple switch to cut the power manually.

Dave