Zero volts on yellow wire to starter solenoid

[cassidyp]

As the title says we have zero volts to the solenoid from the yellow wire. solenoid & starter work fine out of car, but getting no power to the solenoid from ignition. Checked ground strap from trans. to chasis - ok, Any help appreciated or suggestions? We did a search, but the information is not on specific topic...

[304065]

Patrick, can you go into more detail?

You turn the ignition key and get nothing? Measured between ground and the yellow wire? Good battery? Continuity between the yellow wire at the starter and the back of the ignition switch? Engine in the car or not? What car?

[cassidyp]

Sorry about the lack of detail. In the throws of trying to get it running forgot to post. Car is a 1972 911 T that I rebuilt the engine back to stock specs 2.4 MFI. Project has been going on for approx 3 years now. ( glad I bought the 71 to drive & enjoy while working on this car) A friend is helping me with this latest snafu due ot my very limited electrical backround.

Reinstalled the engine / transmission back into the car.
Ground strap from transmission is properly secure and grounded.
New battery installed yesterday, grounded properly, etc...
We are not not getting positive volts on yellow wire. Does this mean problem is in ignition or 14 pin connector?
Test show that we have 12 volts on red starter wire, but not yellow wire.

I did remove the starter assembly from the car and tested it. It works as it should.

Thanks again

[911mot]

You will only get 12volts on the yellow wire with the key held in the 'crank' position. If no voltage in that position it could be the switch at fault.

[911mot]

If you are desperate to start the engine (as I was once) you can bridge across from terminal to the other. The thick wire carries the current to crank the engine - all you do is 'borrow' a bit of that current to engage the solenoid.
Snap-on sell a tool for this. Crocodile clips to each terminal and a thumb trigger switch.

[jpnovak]

Start looking in several places. REmember, key on and in "start". you will need help for this one.

first, check for 12V at starter solenoid - NO then move back to the next contact.

Check for 12V coming out of 14-pin connector. Should be pin #1. If YES, check continuity between 14-pin connector and starter solenoid. If NO, check for 12V at the second 14-pin connector at the bottom of the relay/CDI panel.

12V = Y, check continuity, = N, go back further.

next step is to check for 12V at ignition switch. I don't recall what pin it is. If 12V out of starter, run a jumper from starter to 14-pin connector and see if starter runs. check continuity from switch to rear of car.

The problem should only be in one of those spots. Best of luck.

[RetroSC]

Not sure if mine is the same, but on my 67 the switch was getting flakey (the start position key switch). This switch makes the yellow hot and trigger's the starter. Anyway, I wired in a small relay so this current wasn't traveling directly through the switch anymore and haven't had a problem since.

Mine was a hotstart issue, which can usually be a weak ground or bad seleniod(SP??), but mine wasn't either of those. Traced it back to the switch.

As was said above this only get's hot when in the start position, so test that first.

[911pcars]

I performed the same mod as Retro.

Remove the ignition switch from the IP and check the yellow wire (#50) for voltage in the crank position. If there's voltage here and none at the same wire on the solenoid, you've got an open circuit inbetween.

If no voltage at the switch and other circuits are okay, the crank position of the switch is NG. At this point, you can either buy a new switch (NLA?) or add a relay with a remote starter button.

Here's a diagram of the start system including the add-on relay.

http://members.rennlist.org/911pcars/RemoteStarter.htm

Sherwood

[cassidyp]

Many thanks to all who have offerred advice on this problem. I will try to do as suggested tomorrow and let everyone know the results. Sincere thanks again.

[cassidyp]

Took apart the 14 pin connection. Found the yellow wire was on # 2 pin vs #1 pin where it should be. Looked at the wires on the back (male side of 14 pin connector) and am now trying to match the wires from the female side, but the color codes of the wires are not the same? Can someone tell me the wire colors on the female side for my 72 T?

From the Male Side I have 1- Yellow Wire, 2- green wire, 3 Green w/ black, 4 Green w/ red, 5 - Green w/ yellow, 6 white, 7 Black w/ red tracer, 8 gray wire, 9 black w/ purple, 10 not used, 11 Blue wire, 12 Orange, 13 Black and 14 red.

thanks in advance.

[304065]

Patrick, check here, everything you want including annotated diagram.

Good luck! Are you coming to Hershey? I'm going to bomb down there in my '66.

Retrofitting a 69-73 MFI engine to a 1966 carb'd 911?

[cassidyp]

John,

I am planning on being there Saturday April 22nd at Hershey. Fellow Pelicanites should hook up while there for some cold ones or lunch or perhaps both?

Patrick