Ignition / Starter voltage drop on 77 280z

[MH77280Z]

Hi Guys,

I posted a year ago that I bough a Auto 280z and finally I had it running. Had to do quite a lot of work and it still need more tuning but I was able to get it running on road. The problem is starter voltage !!!

I have the new Nissan OEM fusible links installed as well. When you turn the ignition sometimes the starter does not get engaged and if it does it does not get full voltage. We have to use a remote starter button and directly supply voltage to the starter and it then cranks up nicely. The battery is brand new.

Can someone guide me what to check between ignition and starter? I would assume there is somewhere a relay also involved.

[SteveJ]

Are you trying to start the car without the seat belt buckled?

For the automatic, there is a relay in the circuit.

It's located near the voltage regulator.

 

[MH77280Z]

1 minute ago, SteveJ said:

Are you trying to start the car without the seat belt buckled?

For the automatic, there is a relay in the circuit.

It's located near the voltage regulator.

 

Hmmm - yes sir we have not hooked the seat belt!!! but I can try that tomorrow and report back.

[SteveJ]

You may end up bypassing that relay if all else fails. You can also test to see if that's the problem by using a voltmeter.

Measure voltage to ground on each side of the relay. The black/yellow should be carrying voltage to the relay, and I think it might be a yellow wire exiting the relay. Anyway, that wire exiting the relay is the one that goes to the solenoid. The wiring diagrams I have aren't great about showing the wire colors there.

[MH77280Z]

1 minute ago, SteveJ said:

You may end up bypassing that relay if all else fails. You can also test to see if that's the problem by using a voltmeter.

Measure voltage to ground on each side of the relay. The black/yellow should be carrying voltage to the relay, and I think it might be a yellow wire exiting the relay. Anyway, that wire exiting the relay is the one that goes to the solenoid. The wiring diagrams I have aren't great about showing the wire colors there.

Where is this relay located?

[SteveJ]

[MH77280Z]

6 minutes ago, SteveJ said:

Thanks!

[MH77280Z]

On 1/23/2022 at 11:36 AM, SteveJ said:

Thanks!

 

On 1/23/2022 at 11:43 AM, MH77280Z said:

Thanks!

Paid a bit more close attention this time. It was beeping as intended without the seat belt. With the seat belt it did cranks nicely. Relay turned up fine i think.

I started cold so it did gave me some problems at the start. I am changing the temp/thermo time/cold start valve connectors as they are all loose and broken next. Test out the cold start injector on the machine and finally its time to change the thermal coupler on the fan.

 

[SteveJ]

You gave enough details to get a good guess.

I'm glad it was that easy.