oh I know wher eit is. Not sure if it has 14 pins but I know what you are talking about. And yes, I check it twice.
Thanks.

11.xx is low? umm... I have read other places as Sherwood was speaking. While cranking it requires 9v. My shows 11.xx everywhere except in the engine compartment. IN there, it shows 7.xx while the key is at cranking position. Which is low.

OMG, Randy, I do have the problem :lol: How can I consult you guys. Yes, I can temporarily live with it since I already have the hot start wire setup, and it won't happen during the winter, but I want you guys to believe me... arrgg. This is a famous problem among us.

I didn't say the solenoid just needs 9 volts. I was trying to describe how to measure available source voltage at the end of the yellow wire (at the solenoid). It should be disconnected from the solenoid. However, when measured at the solenoid during cranking, system voltage may drop down to as low as 9 volts (depends on battery state of charge). Mind you, this is system voltage when the solenoid has energized and the motor is rotating. Prior to the starter motor rotating, the solenoid still needs full battery voltage (12 V +) to energize it and complete the path from battery to motor.

I'll assign you a task. Get an electrical diagram of your MY 911 and trace the path, including branch circuits, of that yellow wire (term. 50) from the ign. switch to the starter solenoid. We can then discuss where you might be losing voltage.

From the posts thus far, you may have two issues; reduced solenoid engagement voltage and a heat-related failure to energize the starter motor.

Sherwood

Sherwood,
I agree with this "reduced solenoid engagement voltage and a heat-related failure to energize the starter motor". That is what I thought, and part of the original question came up because of this too. I wanted to know if anyone did the task you just assigned me and ran accross the section I am stuck at, but seem like I have to figure out myself. If I find out anything, will report what I found.
Thank you all.

I believe Pelican has factory wiring diagrams posted somewhere in the Tech section. Repro that section and show us if needed.

Hope this helps,
Sherwood

aftermarket alarm systems may also create 2 yellow wire connectors and the relay contacts for the starter kill. The alarm starter kill may also be using small gage wires to tie it into the yellow.

rnln, PM sent. Tony.

Tony,
Thanks for the advice. It's nice talknig to you. I will try to see if I can do that.
Again, thanks.

Disclaimer: I didn't have time to read everything in great detail so sorry if I misunderstood or repeat unneccessarily.

After working a good number of years as a tech - and 5 of those at a shop specialized in auto electrics/electronics in Munich - I can only concur with JW, Sherwood, and the others. Wires rarely go bad (and then only when subjected to extreme vibration, flexing, or heat) - connectors, terminals, crimps, etc. go bad regularly.

Don't just eyeball the connections or hose them down with contact spray, physically clean or redo them.

Are your grounds - especially the strap at the front of the tranny - OK? (where are you grounding your voltmeter when you're checking?)

I'd redo and triple check everything else before touching the wire.

Hi Steve,
Thanks for reply. I'll make it as short and clean as posible...

Problem: once in a while, twisting the key to start the car doesn't do it, doesn't even make any sound.

Regarding the yellow wire (signal wire from ign. key to starter solenoid). On my car, this wire is running from the dash to floor board, then to driver side rear seat, escapes the cabin to underneath the car (inside a big plastic loom with all other wires), run along the wheelwell, and up to the engine bay at the firewall, along the firewall, and down to the tranny area to connect to the stater.

Found: When the problem occurs, voltage on this wire at the dash is good, V at the floor board is good. When it goes into the big loom underneath the rear seat, I can't measure it and can't tell what is going on in there, because I don't want to cut the plastic cover open. When the wire come out of the loom in the engine bay, V is only ~7v. This is why the starter won't start.

Test: when this problem occurs, I give the yellow wire a 12v right at the firewall before it come down to the tranny area, the car start right away. I had my chances to test this more than 3 times.

Additional info: sometimes when twisting the key, I hear a lound sparkle sound somewhere back there. I affraid this yellow wire has some loose connection, damage or almost damage somewhere back there. I suspect it's within the distant where I can't reach to the wire (between the rear seat and the engine bay firewall)

Conclusion:
I suspect it's within the distant where I can't reach to the wire (between the rear seat and the engine bay firewall)

Thought: in the case when the V is good at one point and is bad at another point (big V drop), then it's as simple as there must be something wrong within that distant of wire. Am I correct?

I agree that wire rarely go bad itself, especially talking about the sparkle I hear and assumming I am not dreaming, but I would think who knows if someone accidentally did something and damage the wire(s)? I agree with you on connectors, terminals, crimps, etc. have more chances to go bad compare to wire. I didn't rule this out of my original plan. I want to replace the piece of wire within that distant, include any of these connector or crimp if there is any in there. And it was my original question, "if there is any Y plit, component within that distant?", not exclude connection and crimp.

Harness damage within a wire loom sometimes occurs as a result of collision damage, or maybe just wear of the wire insulator. It sounds like a partial short; not enough to fry the wire, but enough to bleed off some source voltage and reduce it at the solenoid.

The painful method to repair this is to disassemble the wire loom and replace the damaged section. However, this will probably require removing the drivetrain for convenient access. One option is to end (cut) the existing circuit at a convenient location, then bypass the damaged circuit with a new yellow wire to the solenoid (given no other branch circuits exist in the now-dead circuit section).

In effect, that's what I did to ensure full source voltage to the solenoid. The primary goal was to preserve the crank position on my NLA ignition switch ('69).

Here's the link:
http://members.rennlist.org/911pcars/RemoteStarter.htm

The intermediate relay shortens the source voltage path from battery to solenoid from approx. 10' to about 3'.

Hope this helps,
Sherwood

<i>"One option is to end (cut) the existing circuit at a convenient location, then bypass the damaged circuit with a new yellow wire to the solenoid (given no other branch circuits exist in the now-dead circuit section). "</i>

This is what I was trying to do, and was asking if anyone know if there is any "thing" branches off that wire section I indicated above.

yes I saw that link and was going to do that, beside replacing the damage section of wire.

Thank you.

wow. it has been a long time since I did this. I accidentally get to this thread after clicking on another new thread. I think I should add some comments in case anyone has the same problem.
What I finally found on the yellow wire, when the problem occurred, was voltage read 11v+ at the ignition but only around 7v at the engine compartment.

Test: when problem occurred, twist the key, yellow wire at ignition read 11v+, yellow wire at engine compartment read 7v. Get a long wire to jump from battery (+) to the yellow wire at the engine => engine start.

My guess is that the yellow wire must be damaged somewhere a long the line between the ignition and the engine compartment.

My cheapest/easiest solution was adding a separate wire to the existing yellow wire, from the ignition to the big socket (at the engine fuse panel). The problem has been gone since then.