Please help me diagnose a starting issue/drain/batt going dead...

If unpluging the radio doesn't work try unpluging the small wire going to the starter. Are you familiar with voltage drop testing?

 

Also if you have a solid ground to the frame from the battery then you should be fine with a couple GOOD grounds from the engine to the frame. The frame is basically REALLY heavy guage wire.

 

You really should check battery voltage not running when the problem happens. If you have 12.6v ish a draw is not the problem.

 

I had the same problem. I even disconnected the battery when the car sat for a week. It still would lose a charge. Turns out, I had a dead cell in a relatively new battery.I took the battery back to Kragen and they gave me another. Within a couple of months, the problem started over. Took the battery back and got another (under warranty) which finally cured the problem.

 

I laid on my back in blowing 20 degree weather and changed the starter motor and the solenoid only to find out the top post battery terminals needed to be cleaned. I start with the cheap stuff and clean all connections first. We always cleaned the battery terminal as part of a tune up. It is not a waste of time.

 

OK, so this morning, engine was totally cold, would not turn over, ruh ruh a couple of times, batt tested at 13.9 volts.

terminals and cables look like brand new.

 

I think your meter is off. No way you would actually have 13.9 volts at the battery after trying to start. Need a known good meter. The next time it won't start take a jumper cable and connect from the negative post on the battery to the engine block and try it again and see what happens. Just because wiring and connections look good does not mean that it is good electrically.

 

Get a partner and test the amperage coming out of solenoid or just replace the solenoid - you said it was the old one still if I read that correctly.

There's plenty of evidence that the solenoid does in fact work, it will click and light a bulb - but it does not make enough contact to pass the required amperage to spin the engine. You can rebuild these also

A test on the battery amperage take 30 seconds if you have the tester and even though it shows proper voltage it may not be delivering the proper rated amps.

It think its narrowed down to those two things. If it were mine I'd have a ground directly to the block and then from block to frame and cab. It's just good practice since the starter draws THE MOST give it the best ground

 

This is the right answer. Your meter is not reading the voltage correctly. If the voltage at the battery is the same, running or not, you have a charging issue.

 

If I have one of those problems, I'll swap in a known-to-be-good battery and see what happens.

If that doesn't do it, clean all the grounds, look up under the wire insulation behind the battery cable ends to see if it looks green. That can attract moisture very easily.

Bob

 

Check the ground to the engine. My dad had a simmilar problem. Turned out the the only ground to engine was the manual choke that finnaly burrned thru and would not start at all. Replaced ground to engine and problem solved.

 

If you are going round and round, pull the starter and check it out.
Also do you have electric door openers.Make sure those new cables are good and big enought to trun that 390.

 

I go along with what he said. After sitting all night the voltage across the top of the battery should be right at 12.5 and prime charging voltage is 14.2 but 13.9 would charge the battery if it was actually charging 13.9.

Get a different test meter or take the truck to someone who has a battery/charging system tester.

I'm pretty sure that what you are going to find is that the generator isn't putting out enough power to keep the battery sufficiently charged with your put putting around town. Or it isn't charging at all.

I'd also get a good cable to run the ground from the battery to the block and then run a ground strap from the block to the cab. That will lower the resistance though the ground circuit some.

I honestly don't care if you just carried the battery out of the store, if it' a day,week, month or six months old. If it hasn't actually had a real load test put on it with good equipment it is still suspect.

If you haven't do as others suggested and check each and every connection in the charging and starting circuits. There may be one that isn't making good contact. Usually it's where the ground cable connects to the block or in this case it may be where one of the ground cables connects to the frame. That is three possible bad connections rather than one plus the cable connection at the battery.

I'm still thinking that that cute old generator just isn't up to the challenge and needs to be repaired or replaced.

 

The ground cables from batt to frame, engine to frame, and engine to cab are all good/tight/to bare metal/no corrosion.

The generator was rebuilt by a pro a year ago and bench tested with the voltage regulator then and six months ago when this problem first popped up.

The battery was load tested good today at a local parts place.

I'm thinking it's the starter solenoid or a wire grounding out somewhere. I need to get the truck to the shop to get it in the air to pull the starter and check all wiring. I'll report what I find...

 

Are the Engine and battery connected to the same frame rail? If not it could be an intermittent ground. You can test by running a jumper from the engine to the battery. Easy test.

 

Battery is grounded to passenger side frame rail. Engine is grounded to front cross member.

This problem was not present for months of daily driving after the engine swap/new wiring/cab off frame/painting frame/repairing rust in cab. It started all of a sudden, killed one battery totally, got a replacement, found an issue with the voltage regulator points sticking, replaced that, killed another battery, replaced that under warranty, found an issue with the horn relay wiring and connections that wouldn't tighten up, fixed that with new relay and better wiring connections, still having the issue.

 

Flexing of frame may cause the ground to change. There many not be a good electrical connection between the frame and crossmember. Bad electrical connections can be a bitch to find.

 

Considering I never had a bit of trouble with the old 261 inline that only had the battery grounded to the firewall and no other grounds, I think it's something else.

 

Don't assume anything. Find a local HAMBER or an automotive electrical shop to help you. Some troubleshooting with a good meter will find your problem.

 

xx2

 

Replace the battery in your meter, then test the battery you took out of the meter. Happened to me more than once. Gives you crazy readings.
Starter might need brushes or rebuild. Brushes are cheap and are simple to r&r.

 

Personally I hate batteries in the trunk or in the bed. I mounted mine under the seat in my first 34 P/U it had a hot start problem that I fought for about a year. I was told to mount the ground cable to the block. I was dumb and said but it starts well when cool??? I moved the ground cable from the frame to the trans case and the problem finally disappeared. your problem may not be heat related but it sure sounds to me like it's a connection problem.

I have no idea how the current flowed through the truck before moving the ground cable but I know it was not good enough for the current load of a hot starter motor in the summer.

You can not look at the outside of a battery terminal and assume it will carry enough current to start a car. The starter system is a complete loop from the battery to the starter and back again. Longer loops can and sometimes do create problems. The shorter the loop with the least amount of connections gives the best performance.

The more connections in the chain, the more the chances of a poor connection that can cause your problem. Any link in that chain can cause your problem and you can not know which one by looking at it. I had a 41 woody that would not start intermittently. One day a friend tried to start it while I had my head under the hood. I noticed a spark at the solenoid on the leaving terminal. It looked fine until I grabbed the cable and it moved. The PO had left it loose and I was lucky to find it. Cleaned and tightened the connection and it started every time. Intermittent problems can be a bitch. You can't fix anything that is not broken when you are trying to find it. Any ground wire from the chassis to the engine must be large enough to carry the current of a hot starter motor. A smaller ground cable made to carry the current of the head lights, horn, heater, etc, etc, mounted on the firewall is not enough for starting the motor especially when it's warm and more current is needed.

Wasn't the battery originally mounted in the engine compartment? Much shorter of a chain that could contain a bad link. Originally batteries were moved to the trunk/bed for racing weight transfer. I sure hope you up sized the cable for the extra resistance of the longer cable . We had a start problem with a battery mounted in the trunk of a 31 Roadster. We replaced the cable with welding cable and the problem disappeared.

I've learned and I will never mount a battery in the back again. I want the battery as close to the starter as possible. My current 34 P/U has the battery under the seat with the ground cable running directly to the engine.

Sorry if I ran on but this is a complicated subject.

I was so embarrassed when my first 34 would not start when I stopped for a coffee in a 7-11. I'll never go through that again!!!

 

Tommy,
A big ass chunk of steel that looks like a frame rail will pass current but it sure doesn't work like a #2 copper cable does it ? Usually that chunk of steel works fine for light bulbs , senders, pumps, and other low amp gadgets.

 

It might be something else no doubt .
But do you think a fresh 390 caddy engine might need more Amps and better cables to spin vs the old inline 6 ? Without question it would need more.

 

Today, I put the truck up in the air to inspect the wiring. I couldn't find any issue anywhere with fraying or loose connections.

I pulled the starter and put the new solenoid on. Before changing, it would try to spin slow, ruh.....ruh.........ruh. After changing, it wouldn't spin, ruh...click.click.click..

Before changing the solenoid, I could jump it off. After changing and trying to jump it off, it would spin slow, ruh.....ruh....ruh....ruuuhhh and not start. Before, it would immediately start up with a jump, I didn't have time to see if it would start after charging for a while.


Volt meter on wife's brand new nissan battery running showed 14.6 volts. On the truck battery running, it showed 13.7-13.8 volts. With jumper cables between wife's car and truck, the truck battery showed 14.6 volts before changing the solenoid. With jumper cables between the wife's car and truck, the truck battery showed 13.7-13.8 volts after changing the solenoid.


I'm a little confused, but I'm going to pull the generator and take it to my local pro and have him bench test it again with the voltage regulator. I'm also going to take him the starter and new and old solenoid for testing.

I will report back after Monday...

 

"Battery is grounded to passenger side frame rail. Engine is grounded to front cross member. "

Make a jumper wire here to connect the frame rail to the front crossmember or move the engine ground to the pass frame rail.

 

If the old selonode worked maybe put it back on.
I think you have to fix one thing at a time.
Remove all wires from sel except the big cable from battery,neg cable ground to block.Hot wire to starter, wire from pos to small post on sel.
This should turn starter.
If the bushing is worn on end of shaft.
The nose cone bushing is worn it will turn slow.
Things that could cause short,dis connect horn,radio,anything you wired up.
I think all your power comes off sel post,how many wires on post.

 

OK, it just got wierder. If you recall, the first parts place (advance auto where it was purchased) tested the battery and said it was good. The battery is rated at 1,000cca. I didn't get the readout, just took their word for it.

I went up to the shop today and pulled the battery, starter, and generator. I took them to an Oriellys. The kid behind the counter had never seen a generator and couldn't test it, lol. The starter tested good. The battery showed 0% charge, his volt meter read 12.9 volts. His machine said "bad battery".

So I went to a different advance auto and had them test the battery. Their machine said 11.83 volts, 100cca, "good battery, charge required". The battery had a warranty, so they gave me another one anyway. I had him test the brand new battery for comparison and it showed 12.6 volts, 1024 cca, "good battery". The new battery has not been cycled yet. Their machine wouldn't test a generator.

So, I've got another brand new battery, I think this is the third one.

I'm taking the starter and both the old and new solenoid along with the generator to the pro who rebuilt them tomorrow for bench testing. I'll report back with what he says.

If both the generator and starter check out good by the pro, I've got to be looking for a draw somewhere. It shouldn't be hard, I only have headlights, tail lights, turn signals, and a simple radio. A voltage regulator and horn relay are the only other things that power goes through. All stock mechanical gauges besides the stock ammeter and the fuel gaue.

The generator was polarized and I'll do it again before installing it. Can the generator or starter cause a parasitic draw? Can the voltage regulator or horn relay cause a draw? I assume the lights aren't causing a draw since they are not on when the engine is off, is this correct? Can the ammeter or fuel gauge cause a draw?

 

If both the generator and starter check out good by the pro, I've got to be looking for a draw somewhere. It shouldn't be hard, I only have headlights, tail lights, turn signals, and a simple radio. A voltage regulator and horn relay are the only other things that power goes through. All stock mechanical gauges besides the stock ammeter and the fuel gaue.

The generator was polarized and I'll do it again before installing it. Can the generator or starter cause a parasitic draw? Can the voltage regulator or horn relay cause a draw? I assume the lights aren't causing a draw since they are not on when the engine is off, is this correct? Can the ammeter or fuel gauge cause a draw?



Almost anything can cause a draw- yes. This low draw will generally cause some heat or component warmth, feel for that. high draw and shorts well it's enough to cause a fire.
I understand you don't have a fuse box - but there must be some junction. Put the test light in between the battery ground post and cable and disconnect stuff until it goes out . If it had fuses, you'd just pull the fuses one at a time. You'll have to improvise because there really is no other way to do this with a complete car and everything installed.

 

TF, You seem like a well meaning guy. You are chasing your tail and not getting anywhere. Stop and take some time and go back and read what the people say that are trying to help you. Get a book on basic automotive electrical and learn how an electrical system works. This issue could have diagnosed in a short time by someone with the know how and the right equipment. With all due respect, I think you are over your head, and will spend more time and money than if you paid someone that knows what their doing.