g body not cranking????'s

[dickeymoore]

My 1980 Monte Carlo will not crank sometimes, I traced all the starter wires and ignition wires and replaced them.,and sometimes when I try to start car it clicks and will start but sometimes i have to jump the starter and it cranks, ground wire is grounded to the engine block and the battery is 3 years old new alternator any help?Thanks

 

[383_StealthRam]

Starter, or starter solenoid needs replacing? I don't think you mentioned you replaced that, which would have been the most likely cause imho?

What is the condition of the battery cables, and terminals for both the hot to starter solenoid and ground to block/frame.

 

[dickeymoore]

Starter is a fairly new Powermaster starter, cables are fairly new also.

 

[Ernest]

The 3yr old battery could be on its way out, have it checked out at a local parts store with their tester if none of your own, or a possible problem with the ignition switch and/or connection.

I have one one of these and its very informative...

 

[dickeymoore]

ok Thanks

 

[383_StealthRam]

Is the problem more when hot soaked, is there headers maybe you need a heat shield or the solenoid on the power master is on fritz. You have to troubleshoot when the problem occurs to check if there's power on solenoid wire from IGN switch. It's tough unless you have two people though.

The fact that you put a jump on it gets it to go would kinda point to low battery condition, or bad connection/ corrosion that the extra boost voltage helps overcome so definitely double check those. Also make sure there's no paint on the block where the starter bolts up to.

Hope you find the issue.

 

[CopperNick]

Shift lever on the column or on the floor? On the column and the Neutral switch is located down on the mast below the ignition socket. On the floor and it ought to be attached to the floor shifter inside the console.

Check the neutral switch to make sure that the vehicle is going completely into park at the switch. If the little finger on the bottom of the switch that indexes into the slot on the steering column is worn or bent or damaged then the switch will not consistently fall into park and you will be unable to start it.

If the culprit, then with a column the switch is held in place by two screws that are metric headed, I think, You can both see it and get your hands on it if under the dash but getting it out usually means that you have to drop the column to get more room for the job. Yes it can be done with the column still resident but lots more finagling and cussing involved.

With the console shifter, you have to partially dismantle the console to get at the shifter mechanism. Beware the screws as they are small and love to try to escape and hide.



nick

 

[spongbob]

Checking neutral switch might be accomplished by touching a jumper wire to the purple wire going through the firewall at the connector or going inside to the switch if car starts with a jump wire from the positive side of battery ( in park / neutral please) you might deduce one of 3 things 1 poor connection through ign switch, 2 poor connection through park neutral switch ,3 or poor connection out past firewall 4 suspect + battery v wire 5 if nun of this works it has to be your ground or starter/ solnoid ...sometimes usefull to know' some solonoids will not work below 10 volts ( pull in volts)some for some reason will...gm uses a purple wire to solonoid that can turn a murky pink or fusia color in 40 years...is not entirely impossible that your body ground is disconnected or needs connection cleaned I'm going to mention a hack tip here" for working, ( in the feild) putting old motor oil on some 12 switches will improve there connectivity ( in some cases)...things to try 1 start in neutral ? 2 change solonoid 3 test car for parasitic battery drain/s ( see you tube?)...get an idea of voltages on starting circuit wire befor after mentioned switches or use 12v jump wire to illiminate connection areas ....putting a new starter on people used to run the starter on the ground ( off car )useing jumper cables running it for about 1 minet was supposed to seat new brushes ect. Rarely on old starters you could encounter a dead spot on the comutator and the dead spot would cause a no start worth a thought, didn't some f body cars have a clutch cutout relay or something a voltage meter might help but you may be going back over wire connections sanding surfaces looking for thin,corroded / rusted or burnt spots... last any old chevy gen 2 starters came with 1 tab and 2 tab motors the 2 tab starter motors had more torque ( normally) the tabs being a copper band sticking out of the starter motor that screwed to the bottom connection on the solonoid ( if this connection wasn't tight it would act like the timing was high) eventually frying the tab end thanks for...considering

 

[383_StealthRam]

Voltage drop testing is usually the most accurate way to test for corrosion, or bad cables, connections for a given segment of a circuit.

Sometimes there not easy to do because of physical location of either end of wire/cable, such as the positive battery cable down to starter.

In essence you put a voltmeter leads (on low scale) across the wire. Red lead at battery terminal/post the Black lead at the starter solenoid stud/terminal.

Now while (or attempting to) crank the vehicle, watch the voltage reading on the voltmeter. If there's any more than .2 volts (200 millivolts) showing up, you have a poor connection or there too much resistance/corrosion in the cable.

Electricity will take the path of least resistance, any voltage read on the volt meter is volts being lost across that wire/cable because it's easier to flow through the meter. If it's enough, like maybe 1-2 volts, on an already weak battery (12v or less) it might not engage solenoid or spin starter. At rest, fully charged battery without surface charge should be at about 12.6v +/- approx .1

All of the above assumes the problem is not in that (usually) purple wire that spongbob is talking about. Ergo, you have to confirm that when the problem actually happens.

So, get yourself some length of wire and hook up a little light bulb on it. Like an old turn signal bulb and socket. Connect one side to ground, the other side over to the S (purple wire) terminal on your starter. Run that wire and bulb carefully inside car where you can visually see it.

You've effectively added a "test light" to your starter control circuit and now every time to attempt to crank the starter that bulb should light up telling you that purple wire from IGN switch through firewall and down to starter solenoid is good.

If you go to crank starter, and it doesn't crank but the light is on when you turn key then your problem is the starter, solenoid, battery condition or one of cables/connections.

If you go to crank and no crank, but light doesn't light up either then you need to trace and find the open, problem in that purple wire.

Hope this all makes sense and helps.

 

[383_StealthRam]

I should clarify on the voltage drop testing, you can use it to check connections by putting the leads on (for example) the battery post, then the other on the battery cable terminal checking if they're connected well electrically. Top terminal batteries are easiest to do this, not so much for side terminal.

But the point is you could put VM lead on the ring terminal of a ground cable end, and the other lead to the body metal or engine block adjacent to (but not touching) the ring terminal and check it while cranking.

The idea is to try and flow current through the connection/cable thereby stressing it with an electrical load, to see if any shows up on meter. If you see it on meter it's not going through cable/connection.

Typical problems are paint that wasn't scraped off, loose/stripped fasteners and as already mentioned corrosion. Note of corrosion can be inside the actual cable, if it's old or inferior copper it can corrode inside insulation and you'd never see it but for a voltage drop test. Ask me how I know....

Some might say measure resistance of cable in ohms like a spark plug wire but that's not really stressing the wire like cranking would in case of a battery cable. Or having the headlights on, in case of maybe wire from headlight switch to headlights as another example.

Sorry for the long winded post, but I seem to rarely see anyone mention the importance of voltage drop testing. I think the reason is most times the problem is solved with replacing parts, batteries, switches etc and unseen corrosion or connection issues are less common.

Or they get fixed in the course of the repair, like loose cable at battery/starter while already replacing it anyway.

Good luck!!