No Start Problem - In Process Diagnosis

[My442]

My 70 442 4 speed car did something really odd over the weekend. I was out cruising, and, as always, it ran flawlessly. I have owned this car for over 10 years, and it never left me stranded.

I parked her in the garage, and a few days later, got in to go on a cruise. I turned the key, and there was no response from the starter at all. The gauge needles pegged over, but that was it.

So, I figure it is the clutch neutral safety switch. I get out the volt meter, and test the switch - it tests fine.

Then, I figure that the starter has shorted, or possibly a bad solenoid. I have a rebuilt starter and new solenoid, so I swap them out - same result. No clicking or starter noise, just the needles pegging.

I then decide that possibly the starter switch is bad (it is original), so I drop the column and replace that with a new one - same result. No clicking or starter noise, just the needles pegging.

Hmmm......so I decide to break out the trouble light and start tracking down why the voltage is not getting to the starter. I jump the clutch neutral safety switch, and the wire bundle from the bulkhead under the hood gets hot to the touch. That means that there is:

1. A short in the wire harness to the starter from the firewall bulkhead

2. The wire harness chafed or burned on the exhaust manifold

3. There is corrosion on in or on the connector

I will be pulling the harness off the starter tomorrow and will post results.

I just love electrical problems......

All inputs and ideas welcomed.

 

[brianl703]

Disconnect the starter switch and the thin wire from the starter solenoid.

Connect a test light to the wire that you disconnected from the starter solenoid. Connect the other side of the test light to the positive battery terminal. Is it glowing? If so, you have a short to ground somewhere.

 

[Steve S]

Just bouncing some ideas, Did you load check the battery? measure the volts at the starter solenoid? at the starter? Battery cables O.K. ,Do the backyard test jack up the rear end to get the tires off the ground,make sure it is in N get a long wire from the battery + and touch the solenoid and see what happens .The hot wires seem to say it all.Just beat your head on the wall for a few seconds and chase down the problem.

 

[Steve S]

P.S. nice car.

 

[PT1]

Yeah I would always jump the starter solenoid first see if it rolls over.

BTW..great car. I got clocked doing 129 in a 70 in my buddies 442 on I-90 back when I was a youngster and that car was 5 years old.

Was not easy to explain to Mom & Dad.

 

[Anduril]

Same thing happened in the wife's Cavalier, it would randomly not start and then if you sat there and messed with the key long enough, it'd start and run like nothing ever happened. It went away for a while, then one night it would not start at all no matter what we did. Turned out a wire under the hood by the starter had gotten too close to one of the coolant pipes, melted through the insulation, and was shorting out on the metal pipe. A couple inches of new wire, a couple crimp connectors, and a zip tie fixed the problem permanently.

 

[mechtech2]

You seem to know what you are talking about, but the basic stuff like all power and ground leads being in good shape with clean connections has to be assured first.

 

[AcuraTech]

Originally Posted By: mechtech2
You seem to know what you are talking about, but the basic stuff like all power and ground leads being in good shape with clean connections has to be assured first.


Exactly. Check the basics first. Make sure you're getting good power and ground at the starter. If not, work your way backwards.

 

[Donald]

With a second person to turn the key you should be able to make a lot of progress in 10 minutes with a voltmeter.

If you measure voltage across the battery and have your helper turn the key to start and see no change, that rules out a bad battery and a stuck starter. Assuming the battery voltage was slightly over 12V to start.

Jumping the thinner wire going to the starter soleniod to the main positive one should always turn over the starter assuming you have good power and ground.

Make sure when you measure voltage at the solenoid that the key is turned to start as you could have a corroded connection and get a good reading with no load and a bad reading with key turned to start.

You have, cables, solenoid, starter, secondary relay, key switch and some type of interlock depending if auto or manual. Its got to be in one of those.

 

[eljefino]

What needles peg? And in which direction?

The newish (80s) GM cars have a mode halfway between "run" and "start" called "bulb test" that messes with the idiot lights; I wonder if this is what you are witnessing.

Had a braided solenoid-to-starter-motor wire fray through once, and ground to the starter case. Glowed red like a wick. Was pretty cool b/c it was all soaked in oil.

Yah anyhow I bet the solenoid wire is unfused on your car; there isn't too much stuff that's unfused and would allow the harness to heat up like that.

 

[Gary Allan]

I questioned the "needles pegged" thing when I read it. I was going to ask for qualification. The only time I saw my needles peg for no good reason was when I had a shorted battery. It was just an anomaly in my Tempo. But in this case, if truly pegged, it could point to some other issue. Since he didn't seem to think anything was wrong with it ..

 

[My442]

UPDATE:

I disconnected the wires to the starter solenoid. There is power to the thin wire with the key at "start", and power to the thick wire on "run".

The cables are good, the grounds are good, the nuetral safety switch tests good.

Still - the starter will not turn over or even make a noise.

Keep the ideas coming.

 

[brianl703]

So what happens if you take a fused jumper wire and, with the transmission in park or neutral, connect it between the battery positive post and the terminal on the starter solenoid where the thin wire connects? (After disconnecting the thin wire).

Possibilities are:

1)The fuse blows
2)The starter turns over
3)The solenoid clicks
4)Nothing happens

(For a fuse I'd use a 10 amp fuse).

 

[My442]

Originally Posted By: brianl703
So what happens if you take a fused jumper wire and, with the transmission in park or neutral, connect it between the battery positive post and the terminal on the starter solenoid where the thin wire connects? (After disconnecting the thin wire).

Possibilities are:

1)The fuse blows
2)The starter turns over
3)The solenoid clicks
4)Nothing happens

(For a fuse I'd use a 10 amp fuse).


Thanks

There is power to both wires when there is supposed to be.

It makes no sense that the starter does not even click.

 

[brianl703]

The only possibilities I can think of, if you feed 12V to the small terminal of the solenoid and nothing happens (the solenoid doesn't even click) are:

The starter solenoid is defective
The starter solenoid does not have a good ground (you can test this by jumpering the metal base of the solenoid to the battery negative terminal, if this makes things work then it has a bad ground)

The starter solenoid has more than one small terminal and you have used the wrong one (the replacement for my 1988 Mustang has two small terminals, the original only had one. It came with a sheet of paper saying which terminal to use if your original solenoid only had one small terminal).

 

[Donald]

So what wires are hooked to your starter solenoid? Do you have a manual? At a minimum you have a small positive wire that energizes the solenoid, a large positive direct from the battery and a large positive wire going to the starter. The solenoid probably received ground from its frame connection. The starter also gets is ground from the frame.

If when the key is turned to start you get power to a small wire on the solenoid then it should try to click in and you should hear it. If you hear nothing and the power to this small wire goes on and off as you turn the key to start and let go, then it would seem the problem is either in the solenoid or a bad ground at the solenoid.

All this assumes you have slightly above 12V when measuring.

Try measuring the voltage at the solenoid to a known good ground and to the frame of the solenoid. (Best to do this when key is turned to start.)

You are close. Keep plugging along.

Get a jumper cable and clamp it from the negative of the battery to the frame of the starter solenoid and see what happens.

 

[andyd]

how is the ground between the chassis and the engine block?

 

[Donald]

So what wires are hooked to your starter solenoid? Do you have a manual? At a minimum you have a small positive wire that energizes the solenoid, a large positive direct from the battery and a large positive wire going to the starter. The solenoid probably received ground from its frame connection. The starter also gets is ground from the frame.

If when the key is turned to start you get power to a small wire on the solenoid then it should try to click in and you should hear it. If you hear nothing and the power to this small wire goes on and off as you turn the key to start and let go, then it would seem the problem is either in the solenoid or a bad ground at the solenoid.

All this assumes you have slightly above 12V when measuring.

Try measuring the voltage at the solenoid to a known good ground and to the frame of the solenoid. (Best to do this when key is turned to start.)

You are close. Keep plugging along.

Get a jumper cable and clamp it from the negative of the battery to the frame of the starter solenoid and see what happens.

 

[My442]

UPDATE:

I bench tested the starter by jumping the S terminal with the large stud, and it kicked over.

The last 2 things it could be is the positive cable (new from M&H about 3 years ago) or the Optima battery (about 6 years old).

I think the voltage drop thru the entire starting curcuit may me too low to kick the solenoid over.

Will advise.......:laugh:

 

[brianl703]

You can connect a jumper cable from the battery positive terminal to the terminal on the starter solenoid where the battery cable is connected. This will bypass the battery cable and allow the engine to start if it's bad.

Or you could try jump-starting it to rule out the Optima battery.

Hey, how about checking the voltage at the battery when you try to start it? How low does it drop?