starter solenoid not getting signal

[pond scraper]

I turn the key, lights and gages come on, fuel pump runs but starter solenoid does not get the signal. Starter was tested and works fine. I can jump across the hot and ground of the starter and starter will turn. Is there a fuse or relay between ignition and starter? What am I missing?

[pete3799]

What year car?
Could be a bad ign. switch.

[rattlsnak]

It gets its signal in a yellow wire from the ign. switch that runs through the 14 pin connector in the back engine compartment, then to the starter. A good middle point to check, would be at the 14 pin connector. With the key in the start position, this wire should be hot. If it is, its open somewhere between there and the starter. If it is not, then check it at the switch. There is nothing in between aside from maybe an aftermarket alram system or such.

[Scooter]

Check your ground strap on the transmission.

[Wilhelm]

Try cleaning the fuse contacts/ fuse panel contacts. I dont know which fuse it is in the starting circuit on your car (someone on this forum will be able to tell you) but I had a similar problem on my 71 911S. Turned out one of the the fuses and the corresponding fuse panel contacts on the panel in the engine compartment were a bit corroded. Cleaned the fuse contacts and fuse panel contacts with a fine wire brush and some contact cleaner and evrything was good.

[Eddyvdw]

If you have a MFI, save yourself the trouble and make a solenoid bypass. Nice simply button on the dash will save you a lot of worries. Simply press it for a few seconds every time you start.
Ed

[al lkosmal]

I'm with Scooter on this one....check your grounding...at the battery, and at the tranny ground strap. You can easily check this by running a jumper cable (or other decent size cable) from the battery chassis ground point to the starter flange. This will provide a direct connection from the starter mounting surface (chassis ground point) to the battery ground (at the chassis ground point. ) If your starter/solenoid come back to life....it was a ground problem. I've had this issue with both my 71 and my 73..........cleaned the chassis ground points (at the battery and tranny area) and replaced the ground cables at both points)

Regards,
al

[Walter_Middie]

Pond Scraper,

From one of your other posts, I'm guessing that you are working on the mid-year 911. Your ignition switch has a yellow wire on terminal #50 that energizes the starter solenoid.

[kodioneill]

There is a seat belt lock out on that year car . If the seat belt is not fastened the signal will not reach the solenoid. Sometimes this system is bypassed under the driver seat by jumping the connections maybe one of them came loose.

[911pcars]

Originally Posted by pond scraper

I turn the key, lights and gages come on, fuel pump runs but starter solenoid does not get the signal. Starter was tested and works fine. I can jump across the hot and ground of the starter and starter will turn. Is there a fuse or relay between ignition and starter? What am I missing?

Possibilities include a bad contact inside the ignition switch.

Access the rear of the switch, then measure the voltage at terminal 50 in the start position. During normal cranking (starter solenoid energized), it should read 0 volts. If it reads source voltage (~12 volts) and the solenoid doesn't energize, it's not the switch. Look further downstream.

Temporarily remove yellow (#50) wire from the starter solenoid, then test available voltage again with the ignition in the crank position - should be 12 volts. Reconnect to solenoid, then repeat. If the ground connections are good (gearbox mount, trunk), the solenoid is probably the culprit.

I would suggest removing the starter assy., then bench test to confirm before purchasing a new/rebuilt unit. Compare new/rebuilt with the existing unit before assembly to confirm the dimensions/travel of the drive pinion gear are identical.

Sherwood

[pond scraper]

Thanks everyone it will take me a little while to try them all. How do I remove the ignition switch to check the terminal. This is all new to me, but I have a ton of time and obviosly excellent resources. Thanks again. I would like to drive rather than tow the car to John Walkers shop sometime this summer. I am not YET a car guy. working on it.

[Walter_Middie]

The electrical portion just unplugs from the back. Be careful if you remove the cover of the electrical connector - the wires and connectors will tend to spring out and mix themselves up - not that that has ever happened before.......

[pond scraper]

thanks Walter I inherited the 74 911 from my mother inlaw I'm down here in B-vue

[kodioneill]

Try fastening the seat beat first . The seat has a switch in the bottom to sense if you are sitting in it. Fastening the belt closes the circuit and allows power to flow to the solenoid.

[BURN-BROS]

There may be 2 poles on the solenoid. Verify that you put the yellow wire on the appropriate pole.