won't start!

[tonyk72]

As my intake manifold & distributor project came to a close (ya, right!) I discovered my car won't start!! I have plenty of battery juice..I turn the key & nothing happens...no clicks, no nothing. I'm pretty sure I put everything back the way it was...I was down by the starter (had to remove the heat shield) to get to the drain plug...but that looks OK.
Help!

 

[GWHITE75]

You are a little vague. Did you check to see if your horn or lights worked or did other items associated with turning on the ignition switch, like the radio or wipers work?

You say that all you did was replace the intake manifold and distributor, did you disconnect the positive or negative battery cable? You probably moved the alternator out of the way. Did you re-check all the connections going to the alternator and starter motor? Old wires will break or separate. Some starter wires have fused links in line as well.

Do you have a multimeter?

 

[tonyk72]

I had a mechanic take a look at it just now...he found that there is no juice coming to the starter...
The battery is fully charged with 12.33 volts...
ideas?

 

[Stallion]

So what do you need to change then? Just some wiring? Or the actual starter? Did you short something out? How did you do that? What would be the preventive to something like this happening?

 

[tonyk72]

No clue right now...he's gotta come back to do some more diagnostics...but he's booked up, so that won't be till next week!

Where would I find my starter interrupt relay?

 

[GWHITE75]

I believe you might want to wait for the mechanic to look at the situation.

As you might or might not know, the positive terminal from the battery bolts directly to the starter solenoid on the starter. There is a relay built into the solenoid, which the ignition controls for starting. When your mechanic said there is no juice to the starter, where did he check? Did he check for voltage at the relay on a smaller wire or did he check at the large terminal, where the large cable from the battery is bolted?

Also, you never answered if other electrical equipment works on your car. You need to help us out a little if you want an accurate answer.

 

[GWHITE75]

One other thing I failed to mention, you need to make sure your neutral safety switch is working properly. Meaning if you have an automatic, it needs to be in park or neutral. If a standard, it needs to be in reverse.

Also, I would not suggest you do this, but rather someone who has had to "jump" a starter before while on the road. I had to do this on my 80 Vette years ago with a screwdriver between the large terminal on the starter solenoid and the relay. If you have juice from the large wire and the grounds are in tact, and the starter is good, it will turn over.

Again, someone with experience and possibly a remote starter switch or screwdriver can do this. Doing this will override the neutral switch and ignition and manually turn the motor over. Make sure your car is in park and secured so it won't move.

 

[tonyk72]

GWHITE, I must have edited the reply to your 1st response about 3 times...I forgot to include some of the info on my reedits...

The pos. battery terminal was disconnected for the entire project.

All power accessories work, lights come on, but don't pop up (mechanic said it's normal for vacuum accesories)...same with windshieldwipers...the heater blows....I have no radio in the car so I can't test that.

Not sure where the mechanic checked for voltage, he was working around the starter underneath...

While he was under there, he had me try strarting it a few times. My car is a stick. I had it in neutral with the cluch depressed.
I think he was trying the "screwdriver between the large terminal on the starter solenoid and the relay" trick...but not 100% sure thats what he was doing...he did have a screwdriver in hand..

He wanted to run jumpers or a wire of some sort to the starter from the battery to see if he could get it to start that way...but I didn't have my cables with me...and he was at my house.

Where would I find my neutral safety switch?

Thanks for all your help so far!

 

[GWHITE75]

Good information. Because your vehicle is manual, depressing the clutch closes the safety switch, located under the dash mounted to the clutch pedal assembly.

You corrected me about the need to have the tranny in reverse. As I remember how my 75 used to be, you had to put it in reverse to allow activation of the ignition switch. Yours might not have that feature but you still have to depress the clutch in order to start it correct?

If your mechanic tried to jump accross the battery terminal post on the starter solenoid and the small starter terminal on the starter solenoid and it did not work, although other accessories worked, then you have power to the starter via the large cable. Also, you have grounding, because these other circuits work. I would suspect the solenoid on the starter.

Shorting or jumping across the terminals on the starter solenoid eliminates the ignition switch, wires and safety swtiches. It purely checks the starter for operation. If this did not work, then it looks like the solenoid on the starter motor is shotor the battery is extremely low on current.

Did you try to see if the lights dimmed when you attempted to start the car? If they don't, AND the starter circuit is good, again I suspect the starter solenoid is malfunctioning. If they do, then you might need a battery charge or replacement, eventhough you said it has voltage. Amperage is what makes things happen.

 

[tonyk72]

GWHITE, thanks for the leads! I'll doublecheck to see if the lights go dim when trying to start, but I don't think they did.

Yes, I do have to press the clutch to get it to start.

As far as the solenoid/starter..as far as I know, they are 30 years old. One other thing I should mention. The wiring in that area looks really "beat", its oily and the fabric like insulation is frayed...

Where is the starter relay located? Would that be down by the starter & solenoid?

I also posted this question on the NCRS forum and somebody suggested I look for a purple wire that leads fron the ignition to the relay to the starter...

Thanks!

 

[GWHITE75]

The starter relay is located on the solenoid, mounted atop the starter. It's common for the wires to look like yours do, if they have been subjected to oil and years of operation.

I doubt the starter is 30 years old, but I bet it's old enough to warrant replacement. I don't want you to have to replace it, if it's not the culprit, but it sure is up on the list for suspect operations.

I would first borrow another battery or have yours tested. That's free.

If it were me, I would remove the starter and have it tested. At the same time you can clean and inspect the wires going to the starter. It's not that hard to remove and good preventative maintenance. Especially if the starter has some age on it.

You should be able to have both the battery and starter tested at a auto parts store like O'Rilleys or Pep Boys.

 

[tonyk72]

good advice

I think I'll drop the starter to and take it to AutoZone tonight. I'll doublecheck the battery first, but I just had the same batt. checked at AutoZone last month...and it tested fine.

http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/in_our_stores/free_testing.jsp

I do have a Pepboys in the area as well, but couldn't find anything on their website about FREE testing...

GWHITE, thanks for all your help so far, it feels like I'm actually going to make some progress tracking down the problem...I'll let you know what AutoZone finds tonight...

 

[tonyk72]

the results

AutoZone tested the starter...it spins like crazy. The solenoid puts out 110 amps, they said it should be at 145...

 

[JohnZ]

There is no "starter relay" on a '72 Corvette. The starter solenoid is activated by a purple wire from the ignition switch, which passes through the clutch pedal safety switch on the way to the starter. If you don't show 12 volts at the "S" terminal on the starter (where the purple wire attaches) with the clutch pedal depressed and the key in the "start" position, either the clutch pedal safety switch is shot, or there's an open circuit in that wire between the ignition switch and the starter solenoid. Check first at the solenoid, then where the purple wire goes in and out of the safety switch, and if neither of them show power, probe the cavity containing the purple wire at the ignition switch.

 

[tonyk72]

John, which terminal would the purple wire attach to? All my cables have like a nylon type insulation, so I can't tell the color. Actually, the wire that attaches to the left terminal is red, the insualtion is hacked and I can see the color.
Or am I totally looking at the wrong thing here?
Thanks!

 

[GWHITE75]

Good news about the starter, bad news that you still have the problem.

Not to "harp" on termonology, but the starter solenoid also works as a "relay". What are the terminals indentified as on your solenoid? Are they labeled with an S terminal and an R terminal?

If your mechanic put a screwdriver between the battery terminal and the S terminal, it should have turned over. I don't promote this type of test, but it does work.

You could also attach a remote starter switch between the two, which accomplishes the same goal of turning over the starter without any other outside influence. I have a remote starter button on my firewall and if pushed, it will turn the motor over, regardless of what gear the transmission is in or even if the key is in the car.

Here's what you know. The key won't turn the starter over, with the clutch pushed in. You also think the mechanic tested to see if there was voltage down at the starter, but you are not sure if he tried to short accross the battery terminal and the S terminal on the starter solenoid to see if it would turn over. You have tested the starter and solenoid, which works. You tested the battery a while back and it appears to be charged and capable of turning the starter over, because it works the lights, horn etc.

The mistery is why the starter won't turn over, when installed in the car, utilizing all the cables and wires in the car. It's imperative that you see if it will turn over by connecting a remote starter switch between the battery terminal and the S terminal. This will tell you that the cable from the battery is delivering voltage to the solenoid and it will tell you that the engine is grounded to the chassis, if it does turn the starter over.

You did not disconnect any grounding wires from the chassis to the engine, correct? My grounding wire is located on the passenger side motor mount. This is a heavy wire and it grounds the engine to the chassis.

How many wires did you disconnect from the starter and what terminals were they on, identifying them by color. The battery cable wire is the biggest, then the red wire should be next biggest (10 gauge) and possibly going to the S terminal. This red wire will possibly have an inline thermal fuse in it and was put in by the builder to prevent overheating of the wire due to excessive starting attempts, thus preventing an electrical fire. You also might have a third wire, which connects to the R terminal and goes to the coil up on top of the engine and you might have a ground wire that is attached to one of the two starter mount bolts. The purple wires are inside the car and are part of the clutch safety switch circuit.

 

[tonyk72]

Hmmm, grounding wire on the pass. side...
I did replace one of the heater hoses the same time I did all this work...and it does run on the pass. side. Maybe I did losen a ground? I had to stick my arms inside all over the pass. side engine compartment to route the hose. Could there be hope? I'll check when I get home for lunch...

The purple wire I assumed was routed all the way to the solenoid. I did see a purple wire up by the clutch pedal inside the car...I had to twist my body/head in all sorts of new ways to get a look up inside there...but it looked fine...seemed to be connected to whatever it was connected to...

I had to disconnet a total of 4 wires from the solenoid.
One was a big fat cable which I assume comes from the pos. batt. teminal.
Then there were 3 other cables (looked to all be the same gage, really thin cables) one on each terminal of the solenoid.
I didn't notice any S or R marks on the solenoid.

GWHITE, when you say there might be "a third wire, which connects to the R terminal and goes to the coil up on top of the engine "...I did move the coil around when I pulled off the intake...is this 100% necessary to start the engine? I will double check the connections to that...will a bad coil or connection to it not allow the starter to engage?

 

[GWHITE75]

No, the wire going to the coil would not stop the starter from working.

You would know if you removed or disconnected a grounding wire or strap, when installing the heater hose, I hope. I doubt you did.

I hate to say this, but you really need some local experienced help to solve this. There has to be a friend who can at least help you check to see if the starter will "manually" turn over bolted back up in your car with all the wires hooked back up.

If I were there, I would do the screwdrive trick which would take only a couple of seconds. (I don't recommend you do the screwdriver thing) IF the starter turned over, then I would start looking at the ignition, safety switch, etc. that John Z was talking about.

IF the starter did not turn over, then I would suspect the starter, battery or grounding path from the motor to the chassis. To systematiclly eliminate my suspected parts/circuits, I would have the battery tested, have the starter tested. If thye were good, I would then take jumper cables long enough to run from both battery terminals on the battery, behind the seat, to the starter. Make sure the tranny is in neutral and parking brake is on. Then, clamp the negative cable to a clean starter mount bolt on the starter and touch the positive cable to the small S terminal of the starter. The starter should then manually turn over.

If not, then the battery is indeed bad or the starter needs a new solenoid or rebuilding. Basically, I have replicated what the guy at the auto store did, just with your battery as a power source. It worked at his place but not at yours with your battery.

IF it does turn over, then disconnect just the negative battery cable from the starter mount bolt and touch the positive cable to the S terminal again. If it turns over, then back to checking out the ignition, safety etc. If it does not, then you have to inspect your grounding path for the starter back to the negative battery terminal. This path goes from the starter bolted to the motor, then the motor with a cable or strap to the chassis. Your negative battery cable is also bolted to the chassis in the back, which completes the ground circuit for the starter.

You already know the positive cable to the starter is good, because other items work, like the lights and wipers. Neither of these items depend on grounding from the motor so they will work, even if your starter doesn't.

This is going to probably be something real simple that I managed to make look hard to impossible. Good luck. I have had starter problems in the past and have always been able to fix them. Good luck.

 

[tonyk72]

IT'S ALIVE!!!

It must have been a connection to the starter solenoid. After I had it tested yesterday, I just re-installed it and made sure all the connections were tight. I didn't bother trying to restart it until today (had no coolant yesterday...in the process of draining/refilling). So when I got home from work today, I filled her up and said I might as well try it again...Bingo! She started!

I just hope that this was the case, loose connection...I would hate to get stranded for some other funky problem that could have cause my no starts...
I tried starting a couple times and it fired every time...
Too bad it's freakin' rainin' today!

Anyways, thanks guys for all your help!!!

:s :J :Twist :dance

 

[JohnZ]

Glad you got her up and running - it's amazing how many weird electrical problems disappear when you clean up all the exposed connections so they make good contact (especially all the grounds on Corvettes, where you can't just ground to the body like you can on a steel-bodied car). Anywhere you have a poor connection, you increase resistance at that point and reduce voltage and current-carrying capacity.