No crank, power good throughout

[testerdahl]

Hey guys,

I’ve been racking my head on the problem I’ve been having on my ‘62 C10. Recently, I’ve been having a hit or miss when turning over the ignition. It is either dead completely or fires right up. Lately, the “hit” has gone away and all I have now is a dead truck.

I took my Power Probe and started checking out the wiring. Initially I was having a problem with power going from starter to the ignition. I took the starter back and got a new one under warranty. Remounted it and still have the same problem.

I’ve checked grounds on the starter, ignition switch and even the alternator. I got good grounds on all according to the probe. I then checked the power at the ignition with the key turned. I initially thought I had some rusted out electrical connectors, so I tore it apart and put new connectors on it where needed. With the key turned, I got 12 volts on 3 of the 4 wires - battery, starter and ground. There is a white wire that I have nothing. It could be the issue.

Lastly, I checked the fuses and they are all in good shape. TBC, I have no click, no turning of the starter and I have a good battery (had local parts shop check it out). Any ideas?

[testerdahl]

Thought I'd try my hand at hot wiring the truck and made up these jumpers. I got spark from the purple wiring being connected, but nothing happened at all. No starter turning at all. The battery gauge did pop on to let me know I'm draining the batter a bit. I put a battery tender on it.

[Jferrante]

sounds like a bad switch if you are getting power there. You could bypass the switch and directly power the starter. I would just buy a new switch anyway.

[testerdahl]

Originally Posted by Jferrante

sounds like a bad switch if you are getting power there. You could bypass the switch and directly power the starter. I would just buy a new switch anyway.

I basically did just that, but I used jumper cable to check the starter once again at the battery. It spun. I then spliced the wire heading to the switch and did the same truck. Nothing. Has to be the wire.

Yeah, I bought a new switch anyway. I figure it is 60+ years old and I have it all taken apart. Now is as good a time as any.

[Jferrante]

starter then..go to auto zone and put a new one in, if it works keep it if not return it.

[testerdahl]

After reading a bunch of forum posts and taking a break for a while, I think I finally found the culprit - a bad wire.

Here’s why I suspect it. I made a hot switch setup with some wires and noticed I had nothing still. I then worked back to the starter.

I connected a jumper cable from the switched side of the starter and touched the to the positive battery post. The starter spun! I then cut the wire running to the ignition switch and did the same trick. Nothing, nada. It has to either be that wire or the way the end is connected to the starter.

There is a snow storm moving in and the next chance I get, I’m rewiring that connection to the switch.

[Jferrante]

good to hear

[testerdahl]

New switch bought and still the same problems. Ugh.

To recap: trucks sometimes starts when jumped. I can take wire from starter and touch positive on battery, it will turn over. If I take same wire into the cabin and attach it to new switch, I get nothing ... often.

For example, I put new switch on and it turned over while being jumped. Ran it for a little bit and then turned it off. Tried to turn it back over and got nothing. Jumped the truck and tried to turn it over, again nothing.

Grabbed my power probe and checked all the wiring I could. I'm about ready to call the tow truck to take it to area shop. Running out of ideas. I want to believe it is a bad ground, but I can't find it.

[testerdahl]

FYI - I put alligator clip on ground connection and attached it to a known ground on the firewall. The old switch didn't have a ground, I just figured it wouldn't hurt having one more ground.

[Jferrante]

take a deep breath I have been in this situation more times that I would like to admit in my short years of a home wrencher....
if the engine isn't cranking at all its electrical.If it is but not firing you need to look for fuel/spark.

I think you mentioned no crank so work backwards from the engine. Start with your main ground wires. I am guessing they are on the drivers side frame rail somewhere. Back them out clean and retighten.

Next is starter. I am leaning that you have a faulty starter but make sure all connections are tight and wires aren't exposed. I would run to auto zone and get a new one. Its a quick and easy way to test it - they take returns no problem.

I think your problem lies there - you already did the switch.

Download the wiring diagram here this is my friend Mikes wiring company and the schematic is close to stock:
https://www.americanautowire.com/sho...66-chevy-truck

[testerdahl]

Originally Posted by Jferrante

take a deep breath I have been in this situation more times that I would like to admit in my short years of a home wrencher....
if the engine isn't cranking at all its electrical.If it is but not firing you need to look for fuel/spark.

I think you mentioned no crank so work backwards from the engine. Start with your main ground wires. I am guessing they are on the drivers side frame rail somewhere. Back them out clean and retighten.

Next is starter. I am leaning that you have a faulty starter but make sure all connections are tight and wires aren't exposed. I would run to auto zone and get a new one. Its a quick and easy way to test it - they take returns no problem.

I think your problem lies there - you already did the switch.

Download the wiring diagram here this is my friend Mikes wiring company and the schematic is close to stock:
https://www.americanautowire.com/sho...66-chevy-truck

Good advice. I already put myself in time out. LOL.

I put a new starter on last week since I thought that was the problem as well. I feel like my connection is good since I can touch that wire to the battery and it will crank.

I'll take a look at the wiring diagram. It has to be a ground somewhere right? I just can't imagine it is anything else - new battery, new starter, new switch, etc...

[ray_mcavoy]

Originally Posted by testerdahl

I'll take a look at the wiring diagram. It has to be a ground somewhere right? I just can't imagine it is anything else - new battery, new starter, new switch, etc...

From reading through your posts, I'm going to say that you're most likely looking for a bad connection somewhere in the red wire that feeds battery power to the ignition switch or in the purple wire that runs from the switch down to the starter.

I know you have done some testing and have voltage present on these wires. However, a bad (high resistance) connection will still show voltage present on the wire when there is no (or very little) current flowing through the circuit. But once placed under load (such as trying to engage the starter), the additional current flow across the bad (high resistance) connection creates a large voltage drop that prevents things from working.

To see if that is the case, start by re-checking the voltage on the red wire that feeds battery power to the ignition switch. But this time, also turn the key to the start position while checking the voltage. If the voltage drops way down on the red wire when trying to crank the engine, that is a good sign that the bad connection is somewhere in that wire. With the help of a wiring diagram, you should be able to trace it all the way back to the battery and check for bad connections along the way.

If the red feed wire checks out okay (no / minimal voltage drop), move on to checking the purple wire that runs from the switch to the starter. Note that if your truck has an automatic transmission, there might be a neutral safety switch in the circuit. If so, be sure to check that too.

As far as grounds are concerned, there is only one ground wire that is necessary to make the starter operate. And that is the negative battery cable that should have a good connection to the engine block.

The body of the ignition switch is grounded to the truck's metal dash. And when the key is turned to the start position, it temporarily grounds the white wire which runs to the "hot" light on the dash. That completes the circuit to ground for that light, making it illuminate while cranking the engine. It's a "bulb test" feature so the driver will know the bulb isn't burned out. But it has absolutely nothing to do with making the starter operate.

[testerdahl]

Originally Posted by ray_mcavoy

From reading through your posts, I'm going to say that you're most likely looking for a bad connection somewhere in the red wire that feeds battery power to the ignition switch or in the purple wire that runs from the switch down to the starter.

I know you have done some testing and have voltage present on these wires. However, a bad (high resistance) connection will still show voltage present on the wire when there is no (or very little) current flowing through the circuit. But once placed under load (such as trying to engage the starter), the additional current flow across the bad (high resistance) connection creates a large voltage drop that prevents things from working.

To see if that is the case, start by re-checking the voltage on the red wire that feeds battery power to the ignition switch. But this time, also turn the key to the start position while checking the voltage. If the voltage drops way down on the red wire when trying to crank the engine, that is a good sign that the bad connection is somewhere in that wire. With the help of a wiring diagram, you should be able to trace it all the way back to the battery and check for bad connections along the way.

If the red feed wire checks out okay (no / minimal voltage drop), move on to checking the purple wire that runs from the switch to the starter. Note that if your truck has an automatic transmission, there might be a neutral safety switch in the circuit. If so, be sure to check that too.

As far as grounds are concerned, there is only one ground wire that is necessary to make the starter operate. And that is the negative battery cable that should have a good connection to the engine block.

The body of the ignition switch is grounded to the truck's metal dash. And when the key is turned to the start position, it temporarily grounds the white wire which runs to the "hot" light on the dash. That completes the circuit to ground for that light, making it illuminate while cranking the engine. It's a "bulb test" feature so the driver will know the bulb isn't burned out. But it has absolutely nothing to do with making the starter operate.

Thanks! That is a very thorough response. Supposed to be nearly 60 here tomorrow, I'm going to spend most of my day working on it. There are only 3 parts and like 4 wires. I have to be able to figure that out.

BTW, if you have a minute, any thoughts on what I'm doing wrong with the key? https://www.youtube.com/watch?v=dMlCHFoUndg

Oddest thing I've experienced trying to get it out.

[ray_mcavoy]

Originally Posted by testerdahl

Thanks! That is a very thorough response. Supposed to be nearly 60 here tomorrow, I'm going to spend most of my day working on it. There are only 3 parts and like 4 wires. I have to be able to figure that out.

BTW, if you have a minute, any thoughts on what I'm doing wrong with the key? https://www.youtube.com/watch?v=dMlCHFoUndg

Oddest thing I've experienced trying to get it out.

You're welcome. Yeah, luckily there aren't a whole lot of different parts & wires to deal with. One thing I forgot to mention earlier is the bulkhead connectors. These are the connectors on the firewall where the wiring passes through from the engine compartment to the cab. Both the red feed wire from the battery and the purple starter solenoid wire pass through these connectors. So those are definitely a place you'll want to check for potential poor connections.

Unless I'm missing something, what you're seeing with the key switch might be normal. These older switches are a bit different than the ones found in newer vehicles when it comes to the positions where you can & can not remove the key.

I just checked a spare one I had handy to refresh my memory. On this one, the key can be removed in the "lock", "run", and "start" positions. It can not be removed in the "accessory" or "off" positions. And if you remove the key while it's in the "run" position, the switch can still be turned (without the key) between the "off", "run", and "start" positions. It won't go back to "lock" or "accessory" without re-inserting the key.

[Ken Cook]

I had a 1973 Chevy that nothing would come on. Not even the headlights. It was the main hot wire going to the alternator. It had a bad connector. I don't know if this will help.

[testerdahl]

Originally Posted by Ken Cook

I had a 1973 Chevy that nothing would come on. Not even the headlights. It was the main hot wire going to the alternator. It had a bad connector. I don't know if this will help.

Thanks. Seems like I'm heading down that road too. Hopefully it is just that and I can call it a day on this mystery.

[62chevy302]

I agree with what ray said but you really need a test light with an actual bulb. If the test light lights up on red power feed wire at the back of the switch then you need to check your purple wire to starter. Voltmeters have burned me too much in the past. I always like to use a test light unless im using both in a voltage drop test

[61K10]

Pull the connectors that go through the firewall (that was already mentioned) and clean all of the connectors. Is this all stock wiring or cut up? stock eng or modified? How is the fuse block fed? Don,t see a + wire to the horn relay and regulator. something simple here.

[testerdahl]

Originally Posted by 61K10

Pull the connectors that go through the firewall (that was already mentioned) and clean all of the connectors. Is this all stock wiring or cut up? stock eng or modified? How is the fuse block fed? Don,t see a + wire to the horn relay and regulator. something simple here.

Pulled those connectors off. Good thought. It is all stock.

Engine is a 283 V8 and not the original. I drove to Denver (200 miles each way) and back twice in December. This is a new problem.

Not sure how the fuse block is fed. I'll look at the wiring diagram.

I have a + to all of that. I just took it all apart to see if that was it. It seems to all be working fine.

[61K10]

the pic of your starter you have it,s grounded to the eng (jumper cables) and + from battery to + on the sol and jumper on the s terminal. Take the s term wire and touch it to the + batt and the starter will spin. starter is tested.

sorry if you know all this already.

here is a 61 wiring diagram

[testerdahl]

Originally Posted by 61K10

the pic of your starter you have it,s grounded to the eng (jumper cables) and + from battery to + on the sol and jumper on the s terminal. Take the s term wire and touch it to the + batt and the starter will spin. starter is tested.

sorry if you know all this already.

here is a 61 wiring diagram

Starter is fine IMO. It turns over and the truck will run when jumped. It will also turn over on its own right after being jumped and when the cables are off. It is when I let it sit, it doesn't have any power.

I just replaced the starter as well last week with a new one from the store. It may be a noob assumption, but I'm thinking the starter is good.

[62chevy302]

You need a good hot battery to start your testing. Low or dead batteries will give you inaccurate results

[testerdahl]

Originally Posted by 62chevy302

You need a good hot battery to start your testing. Low or dead batteries will give you inaccurate results

Ok. I just put my charger on it and I'm at 12.5 volts. Time to test connections.

[testerdahl]

Here is my lunch time update:

I started with the red battery cable at the firewall terminal and unplugged it as well as cleaned it. I then put a jumper on it and ran it straight to the switch. As I turned the switch it dropped the same amount on the multi-meter as it did when it came from the firewall.

I then went to the connection before the alternator and did the same test. It dropped the same then the battery died, again. Or so I thought.

I tested the battery and it was done to 8 volts. Barely enough to turn the starter. It occurred to me that maybe the battery wasn't getting recharged as after I jumped the truck. I then jumped the truck again and pulled off the negative terminal. The truck died immediately. Yippee! Alternator then.

Took the alternator back to the parts store and had them test it. They tested it twice and it came back with nothing wrong with it. "Perfect shape," said the parts guy.

Damn. Eating lunch and I'll get back at it.

I'll read through these posts as well and see what else I can trace down.

As it stands, the truck only starts when jumped. Won't turn over again on its own after a I wait a few minutes and dies when I pull off the negative battery cable. I've had the battery tested, starter replaced, alternator checked. I've run continuity checks on the grounds with my Power Probe. I'm taking a test light next and see if I get the same results.

[61K10]

could have a bad cell in the batt.