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Hey guys. I've been trying to fix an out of the blue no crank condition with my 89 iroc 350tpi for years. I've owned it now for 25 years and its done it ever since I bought it off a chevrolet dealership lot back in 1996. It would crank and start most of the time. I would shut off the engine and come back out later and the engine wouldnt crank, not even click. The igniton and dash would power up but wouldnt crank. Let the car sit for a little, could be 5 minutes or a half hour or more and then it would crank like nothing was wrong. Took it back to the dealer several times at that time I bought the car and they never did fix the issue. They did replace the starter, starter relay, ignition switch and even replaced and reprogrammed the keys. Basically threw parts at it. Replacing the keys seemed to make it better but still got the no crank condition from time to time over the years. Fast forward to the present and having more knowledge on electrical diag, I've been trying to fix the issue myself. I know its in the circuit for the solenoid wire. Starts as a yellow wire from the ignition switch to the relay in the kick panel and then goes to the shifter switch which turns into a purple wire going to the c100 connector and then to the starter solenoid. I did find a crap repair of the purple wire at the c100 connector on the interior side of the connector causing high resistance. Did a proper repair there and it seemed to be fixed. Didnt have any issues from there on. Almost 2 years later, my phantom no crank is back. So, further diag, I found the purple wire at the starter solenoid cooked/black. Possibly another high resistance issue. Cut it back to get to good wire and spliced in a new piece and crimped on a new ring lug. At the same time, I also replaced the ignition switch with an acdelco unit, replaced both ignition switch connectors, replaced the starter relay with a standard brand relay, replaced the shifter switch with an acdelco unit, and replaced the starter with a new acdelco starter. The battery is also brand new. Now, sometimes, the starter will just click. Try again, it might click or it might crank. Thought the new starter was bad so I got it exchanged for another new one and get the same results. So more diag, checked voltage on the purple wire at the starter solenoid terminal and when the starter just clicks, I'm getting 7.5 volts. Let off the key and try again and it usually cranks the second try and I get 9.5 volts upwards to 10 volts. I've inspected as much of the solenoid wire as I can under the dash and under the hood and havent found anything. I was thinking maybe something with the c100 connector. Has anyone seen issues with the c100 connector. I've never had the connector apart since I've owned the car and as far as I know, its never been apart since the car came from the factory.
Re: Starter clicks when trying to crank, sometimes.
Try cleaning the grounds on the back of the heads and inspect the main ground cable from the battery to the engine block for insulation that may have rubbed off and damaged the cable. Also clean its connection to the block and make sure it's tight on the battery.
Re: Starter clicks when trying to crank, sometimes.
This is likely a major part of the problem (voltage drop);
This is likely a reliable solution
See this issue on many different vehicles. Often the wires are too small, grounding is poor, and heat contributes to high resistance, as well as crappy OEM ignition switch in the column. This is my work around to protect the flimsy ignition switch and give superior voltage to the solenoid. very cheap to implement.
Re: Starter clicks when trying to crank, sometimes.
Sounds like you may be on the right track, for peace of mind you could tighten up the connection in the c100.
leave the factory grease in it unless its rock hard.
has anyone checked the battery to engine block ground? another easy thing to check and clean
Re: Starter clicks when trying to crank, sometimes.
If the Starter Motor Solenoid makes "contact" and holds (meaning one "Click") but the Starter Motor does NOT turn...
There are several possibilities, including a Starter Motor Armature "dead-spot".
If several "Clicks" can be heard, then the Starter Motor Solenoid is making and breaking "contact".
This can be a Voltage or Amperage issue... also with multiple possibilities.
Note: if you guys ever experience the "multiple Clicking sound". and have normal Voltage while attempting to crank the Engine...
Often the Battery is NO longer able to provide the needed Amperage (and will need to be replaced).
I could not see that as the issue here.
The implementation of a Starter Motor Solenoid Relay, where none originally existed...
Just like Posted above (it cuts out a significant amount of Wire length... replacing all that Wire with 4AWG would essentially have the same affect).
Is always a good idea (NOT always needed... but good none the less).
Sometimes installing a Relay this way, will create enough of a "Band-Aid" Effect to correct a minor issue.
Hot/ heat-soak NO Crank conditions can often occur from poor Grounding (THE MOST IMPORTANT SECTION OF THE POWER WIRING).
A lose/ or undersized/ or incorrectly wired Main Ground Cable can do this.
The smaller Ground Straps and Connections would still power anything that does not have a huge Amperage demand.
Re: Starter clicks when trying to crank, sometimes.
The main reason I started adding the aux relay to most older vehicles was the factory ignition switch in most older vehicles is a flimsy delicate piece, often easy to deform and gets burnt up over time from the current draw of the starter solenoid. Remember you turn the key but the physical contact is made by the switch as it passes current through those tiny surfaces to wires leading to the starter, there is some momentary overlap condition where the contact is just barely made as the unit is turned, high current for such a small area of contact.
The issue is compounded by low voltage which creates a higher amperage current flow exacerbating the issue of already delicate flimsy contacts in the ignition switch.
The relay thus protects OEM ignition switch from being burnt or abused by starter solenoid amps, whether there is voltage drop or not it remains safely detached. Will last much longer this way. Yes adding a larger cable will help where the cable exists but the ignition switch itself cannot be upgraded to a larger cable and will still suffer some deterioration and difficulty with contact area and burning up over time.
09-07-2022, 10:06 PM
