series 2 gamma automatic starter circuit

[keri]

Hi all hope everybody had a good christmas ,i did until the Gamma failed to start which is why need some help i have tested the starter circuit so what i did was a volt meter from pos battery  to main pos lead to starter motor and i have 0v so correct when turned to crank still 0v so ok here, same with earth side from battery neg to motor body again 0v and then then when cranking 0.35 millivolts again all good so here comes my problem i attached positive lead of my meter to battery positive other end to S terminal on motor with ign wire attached this is the terminal which supplies 12v to solenoid to start engine and i have 12v with ignition on so ok here too but then when i turn to crank i still have 12v this should drop to 0v so i need a wire diagram to understand how this circuit works as i have a neutral start switch to consider also does the car have a starter motor relay if so where is it i could start her can any body help with this also if i supply 12v direct to the S terminal it starts right up so i am losing my 12v when cranking to the S terminal.
thanks

[Theo]

Hello Keri. I am somewhat confused with your description but since you say that when you provide 12V "to the S terminal" the car starts, it sounds as if the ignition switch is not providing 12 volts to the starter solenoid. That could be due to a faulty ignition switch, or more likely a bad connection somewhere. Bad connections are the most common problem. Disconnect the wire from the ignition switch to the starter solenoid (I think this is what you refer to "the S terminal) and check to see if you get 12V on the wire when you turn the ignition. If you get 12V (or a few volts e.g. 9V) when the starter solenoid is disconnected i.e. with no load, then a bad connection is your problem. The bad connection could be anywhere including inside the ignition switch. It's a common problem and I had it too. I had just 10V-11V with no load and only about 2Volts under load. Having failed to find the bad connection, I fitted a relay which would work happily with the 10Volts as it has minimal load and the relay switched full battery volts to the starter. Still works fine 10 years later ;-) There's no relay normally for the starter motor but on the SII injected cars the wire from the ignition to the starter motor also energises the double relay which ensures the fuel pump is running while cranking the engine.

[keri]

Hi Theo thanks for the reply i am still struggling to locate the fault and i had the same idea as you and maybe i should just install a relay of my own it was just as mine is an automatic the ignition switch switched live to the starter must then go through the neutral start switch? this is why i thought it had a relay so i could have an issue with the neutral switch as it may think it is in gear?  do you know how this side works as if i install my own relay i need something from the neutral start switch to the relay to stop it starting in gear.
regards
Keri

[Theo]

Hello Keri. Sorry, I saw you said "automatic" but when I started writing my reply I forgot about it!! 
But my suggestion still stands: You need to disconnect the wire from the starter solenoid (S terminal) and then with  your test meter -ve lead on the battery -ve pole and the meter +ve lead on the wire, move the ignition switch to the cranking position and see if you get any voltage on the wire. You must have the wire disconnected for this test so there's no load when you turn the key. There's a lot of load from the starter motor so if it's a bad connection anywhere (including the automatic inhibitor switch) the circuit won't be able to provide enough current. Try this with the car in Park and also in Neutral. I don't think automatic Gammas have a relay for the starter circui.t My Trevi is automatic and has an inhibitor switch but no relay. When I first got my Trevi, it would only start in Neutral and not Park and that was because the inhibitor switch was not adjusted properly. If you get any 'reasonable' amount of voltage on the solenoid wire when it's not connected (anything over 9 volts) then you can fit a relay between this wire and the solenoid to provide battery voltage to the solenoid S terminal.

[keri]

Hi Theo thanks for the information i have done what you suggested but nothing at the s terminal but after some more checking i found a 12v supply into the neutral switch and when i park or neutral a 12v supply out this is the wire i will use to operate my own relay like you did  and fit  it somewhere out of the way so this should take away my problem thanks again for your help
regards
Keri