igmition start problem
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
I getting frustraded with this ignition problem. It come to mind. Just to run a new wire direct from yellow wire to starter motor and be done .
No that is stuped idea. Dont want to do that realy
No that is stuped idea. Dont want to do that realy
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
From the formula;
more resistance in circuit = lower voltage.
Bad /dirty connections will have hi resistance; hence the reason to test resistance on the wiring to starter
Easy test would be as you say to run a new wire from key to starter
more resistance in circuit = lower voltage.
Bad /dirty connections will have hi resistance; hence the reason to test resistance on the wiring to starter
Easy test would be as you say to run a new wire from key to starter
Last edited by rodj; Jan 15, 2012 at 06:53 PM.
Melting Slicks
Joined: Feb 2011
Posts: 2,322
Likes: 6
From: Los Altos CA
When the yellow wire is disconnected no current is flowing so there won't be any voltage drop.
When you connect the yellow and green wires current flows and the voltage drops.
If the battery voltage isn't changing (please check this) then there is a 12.5v-11.6v=0.9v drop due to the resistance of the wires and ignition switch. I'm not sure that's enough to cause a problem.
With the yellow and green wires connected have you checked the voltage at other points in the circuit?
The most important place to measure would be at the solenoid itself: What voltage do you get at the purple wire when it is disconnected from the solenoid? What voltage do you get when it is connected?
Similarly, what voltages do you get when you probe at the transmission position switch, connected and disconnected?
Running a wire from the yellow wire to the solenoid would work but would eliminate the transmission position switch (a safety feature).
When you connect the yellow and green wires current flows and the voltage drops.
If the battery voltage isn't changing (please check this) then there is a 12.5v-11.6v=0.9v drop due to the resistance of the wires and ignition switch. I'm not sure that's enough to cause a problem.
With the yellow and green wires connected have you checked the voltage at other points in the circuit?
The most important place to measure would be at the solenoid itself: What voltage do you get at the purple wire when it is disconnected from the solenoid? What voltage do you get when it is connected?
Similarly, what voltages do you get when you probe at the transmission position switch, connected and disconnected?
Running a wire from the yellow wire to the solenoid would work but would eliminate the transmission position switch (a safety feature).
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
Ok i will have to get back to the car and do all this test you are talking about. Unfortunately. I can only work in the car on weekends. I will try to go to my car some time during the week
Let sayi get low voltage on the starter after i do the test. What this de meenig of that
Let sayi get low voltage on the starter after i do the test. What this de meenig of that
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
I was reading about voltage drop test for the starter system. I find out there is a couple of test i have to do. The problem can be resistance on wire some where. May be on battery wire. Will do test first
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Melting Slicks
Joined: Feb 2011
Posts: 2,322
Likes: 6
From: Los Altos CA
Sorry, this will take some math to explain:
The voltages should add up:
Let
Vsol= the voltage between the solenoid and ground
Vtran= the voltage between the transmission switch and ground
Vrel= the voltage between the start enable relay (the yellow & green wire) and ground
Vbat= the battery voltage
then
Vbat=Vsol + (Vtrans - Vsol) + (Vrel-Vtrans) + (Vbat-Vrel)
Right now, you know (Vbat-Vrel)=12.5-11.6=0.9v which is the voltage drop due to the ignition switch and wiring.
Advanced
Joined: May 2003
Posts: 96
Likes: 0
From: Moreno Valley CA
Ignition Switch
I had the same symptoms with my 87 and finally found the ignition switch was bad on the starter contacts inside the switch. My switch was the original unit so I replaced it with a new one and the problem went away. I have had no startup problem since replacing the ignition switch. Should you decide to replace the ignition switch, take your time and pay attention to the details coming apart and back together.
Gary
Gary
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
I had the same symptoms with my 87 and finally found the ignition switch was bad on the starter contacts inside the switch. My switch was the original unit so I replaced it with a new one and the problem went away. I have had no startup problem since replacing the ignition switch. Should you decide to replace the ignition switch, take your time and pay attention to the details coming apart and back together.
Gary
Gary
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
By checking the voltage drop at various points along the circuit you learn where the high resistance section is---and that's the place you'll need to fix.
Sorry, this will take some math to explain:
The voltages should add up:
Let
Vsol= the voltage between the solenoid and ground
Vtran= the voltage between the transmission switch and ground
Vrel= the voltage between the start enable relay (the yellow & green wire) and ground
Vbat= the battery voltage
then
Vbat=Vsol + (Vtrans - Vsol) + (Vrel-Vtrans) + (Vbat-Vrel)
Right now, you know (Vbat-Vrel)=12.5-11.6=0.9v which is the voltage drop due to the ignition switch and wiring.
Sorry, this will take some math to explain:
The voltages should add up:
Let
Vsol= the voltage between the solenoid and ground
Vtran= the voltage between the transmission switch and ground
Vrel= the voltage between the start enable relay (the yellow & green wire) and ground
Vbat= the battery voltage
then
Vbat=Vsol + (Vtrans - Vsol) + (Vrel-Vtrans) + (Vbat-Vrel)
Right now, you know (Vbat-Vrel)=12.5-11.6=0.9v which is the voltage drop due to the ignition switch and wiring.
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
I had the same symptoms with my 87 and finally found the ignition switch was bad on the starter contacts inside the switch. My switch was the original unit so I replaced it with a new one and the problem went away. I have had no startup problem since replacing the ignition switch. Should you decide to replace the ignition switch, take your time and pay attention to the details coming apart and back together.
Gary
Gary
thank you for the sugestion
Melting Slicks
Joined: Feb 2011
Posts: 2,322
Likes: 6
From: Los Altos CA
If the voltage drop is largest between the battery and relay then the ignition switch is suspect.
As an experiment you could try a wire (and switch) from the battery to the green wire. If that starts your car every time and the normal connection (yellow wire to green wire) doesn't then, again, your ignition switch or wiring is suspect.
As an experiment you could try a wire (and switch) from the battery to the green wire. If that starts your car every time and the normal connection (yellow wire to green wire) doesn't then, again, your ignition switch or wiring is suspect.
Team Owner
Joined: Jan 2003
Posts: 20,254
Likes: 221
From: Summerland B.C. Canada
No. Before the gear selection swich i get a drop. Where the yellow wire meet with the green and white wire
Yellow wire coming from the ignition swicth. Meet with green and white wire before going to GEar selector switch. When i connect this 2 wire is when the voltage drop. Dont know why i get a drop. In voltage. Just by conectin 2 wire
Yellow wire coming from the ignition swicth. Meet with green and white wire before going to GEar selector switch. When i connect this 2 wire is when the voltage drop. Dont know why i get a drop. In voltage. Just by conectin 2 wire
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
If the voltage drop is largest between the battery and relay then the ignition switch is suspect.
As an experiment you could try a wire (and switch) from the battery to the green wire. If that starts your car every time and the normal connection (yellow wire to green wire) doesn't then, again, your ignition switch or wiring is suspect.
As an experiment you could try a wire (and switch) from the battery to the green wire. If that starts your car every time and the normal connection (yellow wire to green wire) doesn't then, again, your ignition switch or wiring is suspect.
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
also just when out I got my self a cable. to try to connect battery to green and white wire.
here is a link of some of the test I will do. in case someone need to do some test also.
http://www.aa1car.com/library/voltage_drop_testing.htm
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
but not me. I will finish this the right way.