Before I go totally insane I'm hoping someone can help me through trouble shooting a problem with the ignition switch not actuating the starter. First a little information, I have a late model year 1972 1.7 with the fuel injection removed and a carburetor installed. After six months of working on the car I've finally gotten to the point where I have installed the motor with a new starter The car has been apart for 12 years sitting in the garage. First the starter failed to work when I tried to turn it over. Thinking the new starter was bad I took it off and had it tested this morning at the auto parts store it works fine. I also had the battery checked and it is good as well.

I put the starter back in and it worked four or five times so I thought it was fixed. I then hooked up the fuel line and went to try and start it and the starter wouldn't work again!#@%###. I can jump it across the positive battery cable to the solenoid and it works. I have 12 volts on the yellow wire to the started solenoid when it is disconnected and 8.5 volts when it is connected when the key is turned. I have checked the relay board at pin # 6 and I have 12 volts there when the key is turned with the connector off. I ran a jumper wire to the solenoid from pin# 6 on the relay board and the voltage goes down to 8.5 when the key is turned to start so I think I have eliminated that the yellow wire is bad from the relay board to the starter solenoid.

I can't tell from the schematic my manual if there are other things in the circuit I should check. I'm wondering if my ignition switch is bad.

Anyone have any ideas or insight? Any suggestions or directions would be gratefully appreciated.

Thanks,
Jsaum

Ignition switch? that would be my guess..

Make sure the ground strap is installed between the transmission and the body on the back of the transmission.

Second the ground strap as a possible cause of a slow turning starter that does not allow a hot engine to crank and just generally wreeks havoc on the electrical stuff. Also I think I remember reading the gear box is effected by the lack of a ground strap. Myth or urban legend?

But I would say it sounds much more likely you have a bad switch. You could test the switch at the dash end to be sure you don't have a broken or shorting wire running back to your solenoid.

The ignition switch and the wire running to the rear board have always been a weak link , so these are the suspects of your problem, a voltage drop. Bosch makes a 'hot start kit" to overcome this proplem. Basicaly uses a relay to supply voltage directly from the battery using the wire from the ignition to trigger the relay. Then again check your grounds. Hope this helps.

Jsuam,
This is a common problem with these cars. Can seem to be complicated,but, step by step working through this will work to find the problem.
First, your yellow wire has 12 volts with key to start and yellow wire disconnected from starter. Good, this means your ignition switch is making contact. When you hook the yellow wire up to the starter, the voltage drops to 8.5. Some voltage drop is to be expected as you are trying to energize the solenoid, but yours seems to be too much.
There can be several causes for this and all are probably bad connections. Definately check the transmission ground strap. Then check out the connector on the yellow wire and replace it if it looks corroded at all. Remember, these connectors are subject to outside forces, and water/heat can really affect them over time.
These selonoids have two , yes two, circuit paths for the holding coil to keep the selonoid energized while the starter motor is turning over the motor. Is your starter a new bosch one? Not sure if the other non-bosch units have the second holding circuit, which places added strain on the ignition key circuit. The second holding circuit is made when the selonoid contacts at the rear of the selonoid are made internally.
If you would like some more indepth explanations, PM me your phone number and I'll give you a call.
Tom

Guys,
Thanks for the help! I checked and cleaned the ground connections at the transmission, just above the relay board, and the negetive connection for the battery. Whats curious to me is the starter runs great when jumped and after I installed it the second time it worked good a few times then quit. I was wondering it there was another relay in the system therre doesn't seem like it. The new starter is a remanufactured one from Oreilly's. Tom I'll take you up on your offer I'll PM you my number.

Jsaum

Ha, went through 4 starters from them before I got one that works right. Good luck with those things.

I have always ran a direct ground from the starter to the body. The trani ground strap just doesnt cut it...

Do you run it to the same point?

If my car did this I would opperate the starter from the solenoid, feed it with power off a battery positive source. That will narrow down some things. If it works good then its likely the major inputs and grounds are fine. If not then you need to make sure battery voltage is up and the major power inputs are good. That list would include the battery grounds on both ends and the positive cable at both ends. I would say the starter is always something to look at as well.
The most important part is you, if you can evaluate good things from bad things If not all bets are off..

So here's where I'm at on the trouble shooting. The battery is good 12 plus volts and 550 cranking amps. Checked and rechecked all of the grounding points. I also used my set of jumper cables as extra grounds from the negative post on the battery directly to the starter housing and to the engine. I ran a separate wire from pin #6 on the relay board to the starter solenoid the starter still won't crank the engine over. A jumper wire from the positive cable to the terminal connector on the solenoid will crank the starter over like it should if using the key. I don't think I have a grounding problem and I believe that I have proven that the yellow wire from the relay board to the solenoid is good. I'm still getting 12 volts with the yellow wire disconnected from the solenoid and 9.5 with it connected. The first picture is the jumper wire I placed on pin #6 on the relay board. The second picture I have attached a lead to the volt meter so I can read the voltage when I try the key in the start position. The next one shows how the voltage goes down to 9.5 volts when the key is turned. The next two pictures show how with no wire connected to the solenoid I have 12.7 volts at pin #6 on the relay board ! I think my problem must be the starter switch.

My bet is on the ignition switch.
I had the same problem with Papa Smurf. Sometimes it would start just fine, then I'd come off the track, and sometimes there was nothing (power was on, fuel pump running...no start) not even an attempt to start like a low battery. Strange though, when I would 'jump' the battey with a charger or something, it started fine.

I have since disconnected the key switch and went to a push button. Never have a problem anymore.

On Huey, we have a strange occurance. always starts, but sometimes, the car just 'shuts off' while driving. Turn the key off, back on and it starts right up and goes along fine. Again, I think it's in the key switch. Its not that uncommon, after 40 years, the little metal pieces in the switch start to wear out. Replace the switch and I'd bet it works fine.

New switch is on the way ordered it up yesterday morning! I'm going to pull the old switch out this evening and see if a little inspection and cleaning might make it work.

Thanks for all of the help!
Jsaum

Yep- the ignition module on my car had obviously been cracked for years- which may be why the car would always start with a FULLY charged battery, but anything less would not do it. This repeaed no-start/ charge battery process also helped kill my battery I think, so that when I replaced the ign module, the fix was only about 70% reliable. Got a new battery too, and now it cranks right up.

My point is that the cumulative effect of a problem can complicate the diagnosis too.

Mystery solved sanity restored! Underthetire got it right it was the crappy starter from FLAPS! Orielly's I had to take a battery in with jumper cables and remote starter switch and show the guys how even though the machine would test the new starter as good a battery wouldn't engage the solenoid I'm not crazy! I walked out with a replacement worked like a champ first time I turned the key! After a little rustling with the ignition systems I got it to start. Hearing the motor for the first time in twelve years was a great sound! Can't wait to take it around the block maybe a few days away just have a few more bugs to work out!

Thank for all the help,
Jsaum