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1956 ground issue? RESOLVED

Started by Lexi, August 23, 2017, 04:52:07 PM

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Lexi

I have had a dreadful intermittent no-crank, no-start issue for 5 years with my 1956 Caddy. It comes and goes and can even lie dormant for months, so tough to troubleshoot. I had found a lot of issues, any one of which could have caused this starting problem grief. Had starter rebuilt, then re-checked with a bench test, swapped out ignition switch at least twice, changed terminal ends there, put on a replacement used ground strap (the old one was falling apart), replaced neutral safety switch...to name a few. I had issues with them all. I believe that sometimes more than one would manifest at the same time. Hope I am nearing the end of this journey but the car Gods refuse to shine on me.

Today after adjusting the carburetor, dwell etc., car died while idling. That is a first. Then no-crank, no-start, no lights no nothing. By the time I got the car jacked up with volt meter for troubleshooting etc it started. Always the same, after about a 20 minute cool down, it starts. As nothing worked I suspect a bad negative ground, (again), perhaps adding to a resistance problem somewhere. The flat braided ground strap first bolts to the frame then carries on to the starter motor. All of these connections are clean. I do suspect the connection at the frame which is a screw into the top portion of the frame (impossible to see area), and as I recall not possible to put a bolt with a nut on the other end to ensure a secure ground. Is this the way they came from the factory? Just a screw for the frame ground?

Anybody run into this with their Caddy and if so any suggestions? I think I would like to add an extra ground just to be sure as today I had 2 power failures and both were cured when I jacked the car up (passenger side so where the neg strap is). Seems some frame twist may have temporarily fixed the problem. Any suggestions as to how and where to run any extra grounds and what gauge of wire is recommended? Would like to keep the braided strap as is original equipment but only if I can properly ground the car even if that means augmenting what is there with some new ground wires. Thanks for any assistance. Clay/Lexi

Caddy Wizard

#1
Is you car air conditioned?  Does it seem more prone to this issue after running the car with the AC on?  Is the problem more likely to rear its very ugly head after the engine runs for quite a while, or can it pop up after only a few minutes?

I have some ideas...feel free to call me after dinner.

Art Gardner
Art Gardner


1955 S60 Fleetwood sedan (now under resto -- has been in paint shop since June 2022!)
1955 S62 Coupe (future show car? 2/3 done)
1958 Eldo Seville (2/3 done)

Lexi

Hello Art. Great seeing you at the GN. Today it did it after warmed up. I have had a lot of issues with other problems that also impacted starting the car, but this time I suspect it is the negative ground strap. Jacking the car on that side where the strap is bolted fixed it as if frame twist gave me a better ground. Will give you a shout for some better insight. Thanks, Clay

Jeff Rosansky CLC #28373

#3
Does it stumble and die or just die?
All you need is enough of a ground to run the ignition.
May I suggest you try the following--
Next time it completely dies and the car is dead, and before you touch/move anything take a meter and see if there is any continuity between the battery ground and the engine. That will tell you if what you are suspecting is true.
Then, you can just run a temporary ground from the battery to the engine and drive it to see if she will keep running. Turn off all other electricity so you dont over tax your little ground.
If it stumbles and dies then just stand there with a jumper wire. When it stumbles connect your jumper from battery negative to the block and see if she continues to run.
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

bcroe

Seems like you had multiple problems.  My starters have a couple terminals on
the fender for the starter main bat and ign start wires.  If all else fails, I can
put a screwdriver across and it should crank.  Or bump it a few times. 

My rules.  First note if all the lights (overhead, whatever) stay on; if yes, the
problem is not a lack of battery or its post connections.  Next, hold the crank
position 15 sec and then jump out, see if any of the battery-starter wire
connections are hot.  The hot one is a poor connection.  Bruce Roe

Lexi

All great suggestions from this Forum and email from member Jose Gomez as well, and Art. Gonna dig into it tomorrow but it looks like someone has moved the original battery ground on the frame, by-passing the 'nut and bolt' approach to using a large sheet metal screw for the main ground. Not a sure way of obtaining the best ground. I am also missing one of the 2 engine bay ground straps. Gonna use all that I learned here. Great forum and thank you all! In answer to Jeff's question it just died. Twice, but got it started both times only after I floor jacked it (on the side where the ground strap is fastened to the frame).

Good idea Jeff, I will try your suggestion. Never thought of that. Will check out Bruce's ideas on this to. Clay/Lexi

Steve Passmore

If it's completely dead without lights even, this means no power at all and can only mean a failure in the battery circuit.  I have seen this many times and it's always been the battery safety switch. There are a lot of cheap import types out there and they fail for no reason.  Many friends of mine have changed them on a regular basis. One friend had his fail within days of fitting, the second one only lasted a month.
Next time it dies undo the terminals and bolt both wires to the same terminal to bypass the switch. This will at least eliminate that possibility.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

Caddy Wizard

Clay,


Here is a photo showing the general location for the main ground strap on the frame of a 55 FW.  Yes, I know, this ground strap is not correct -- it should be one strap, not 2 jumpered together at the frame.  But the photo does show where the ground strap is supposed to connect to the frame...

Art
Art Gardner


1955 S60 Fleetwood sedan (now under resto -- has been in paint shop since June 2022!)
1955 S62 Coupe (future show car? 2/3 done)
1958 Eldo Seville (2/3 done)

cadman56

Clay,
If you have lights you have a ground on the frame or the one engine to cowl ground braid strap. 

Power for everything in the car comes from the battery post on the starter solenoid and with only one wire.  The connection on the terminal could be weak or almost broken.
 
Have you overlooked an inspection of the positive cable and the terminal connections at the battery post on the starter solenoid?

Every 56 I have disassembled to bare frame had a very heavy self-trhreading bolt on the frame ground, never a bolt and not combination.

Do get both engine to body braided ground straps installed.

Are you using a 3EE or 3ET battery?  Check posts for looseness/battery corrosion at the posts.  Check for corrosion inside the battery cables.

God knows I have been wrong many times but I have a humch you will find the issue on the + side of the system.

Do let us know what you find.  So many queries for help never reply to what had been found.
Good luck,  Larry
1956 Cadillac Coupe deVille (sold)
1956 Cadillac Convertible (sold)
1956 Cadillac Eldorado Seville (sold)
1967 Cadillac Eldorado (sold)
1968 Cadillac Convertible (Sold)
1991 Cadillac Fleetwood Brougham dElegance
Larry Blanchard CLC #5820

Lexi

#9
Hey Larry/Art. My positive cable is a new 1 gauge type. All connections super clean via a dremel tool. Battery is still OK to good, an Exide 3EE.

Some swear the negative ground connection is a nut and bolt through the ground strap to the frame, though Larry's experience is what I have on my car, a self threading large bolt (and no nut). I spent time last night re-reading older related posts on the Mid Century Cadillac Forum of the CLC and there was a lively debate about where the 1956 ground strap even ended; starter motor or bell housing into engine? There was also another discussion about where on the frame the ground strap should be fastened, with a picture. Seems there is still some confusion on these matters as even the Forum Administrator  exclaimed humorously that he was now 'confused'.

There was some rain today so I did not get much done to the car but will try again tomorrow. I did some looking around and I did note that one of the wires from the solenoid creeps up between the firewall and the engine, and I see that it is butt connected to another (different colored) wire. With grime not sure of that color and it is not possible to service in that location. I will try and pull the solenoid wire cluster up top to examine, tomorrow. Correct me if i am wrong, but I believe one of the solenoid wires that is attached to the constant hot solenoid terminal, (positive battery connection), actually runs to the headlight switch 'Bat' connection. Have not studied the chassis wiring diagram yet, but as these old cars have many components that will 'run' without the key on such as power windows, lights etc., that is probably the feed. Larry may be correct in that there could be a problem on the + side, though I don't think that would also prevent the starter from working, (unless ignition switch bad, but I have swapped that out at least twice). Wiggling the Neutral Safety Switch did nothing, but that is also swapped out with what looks like a near NOS one. Starter is rebuilt and serviced a few weeks back for preventative maintenance. So that aspect of the car has been a 'dog's breakfast', but I am hoping to finally put this nightmare to rest!

I keep going back to why the car failed twice with no power but floor jacking it on the passenger side twice 'corrected' the problem immediately-hence my suspicion with the frame ground, (as located also on that side). As the problem is fugitive it is difficult to troubleshoot. I also have only one braided firewall strap, (driver side missing), and will be correcting that soon. I will keep all posted so hopefully anyone else who runs into similar problems can benefit from these posts. Thanks for all your input and please post any new ideas that you may have on this. Clay/Lexi

cadman56

Clay,
I know you and everyone else knows this but I will repeat it here.  The old vinyl/plastic wiring may look good but always suspect the wire because the insulation gets very brittle.
If memory serves me correctly, can't read anymore w/bad eyes, you should have a small black wire (to blower motor), heavy purple wire ( to NS switch), a small yellow wire,( to coil side of ballast resistor), and a larger red wire ( carrys all power to IGN switch) in that bundle between the engine and firewall.  That red wire goes to the BAT side of the IGN switch or to the headlight switch then to the IGN switch.  All other non-switched power feed goes from the IGN switch to the power circuit breakers inside the right side kick panel.
One braided ground braided wire from engine to cowl blister should be sufficient enough to carry ignition and lighting current requirements but do add the second one.
The negative cable should be under one of the starter mounting bolts, I believe the top one.
Wish your car were here in my shop so I could help you.
Keep us posted,
Larry
1956 Cadillac Coupe deVille (sold)
1956 Cadillac Convertible (sold)
1956 Cadillac Eldorado Seville (sold)
1967 Cadillac Eldorado (sold)
1968 Cadillac Convertible (Sold)
1991 Cadillac Fleetwood Brougham dElegance
Larry Blanchard CLC #5820

Lexi

Larry you are correct, and I did have wiring problems at the solenoid that I since corrected. I changed all the ring connectors and cut the wires back a bit and soldered new wire in then applied heat shrink. Did the same at the ignition switch as well. Some of the wires were brittle and under the plastic the wires were breaking internally at their connectors. Going back at it today. I told Art Gardner that at least my car is 'house broken', meaning that when it breaks down it almost always happens in the driveway! Wish me luck! Clay/Lexi

walt chomosh #23510

clay,
  I've had battery cables corrode at their mid point under the insulation!.....just a thought....walt....tulsa,ok

Jeff Rosansky CLC #28373

#13
Ok, so the car is completely dead and no wires get hot (no dead short killing everything). Then after jossiling the car it wakes up again. This leads me to think of 7 possibilities.
1-4 are the terminal ends on each battery cable.
5 and 6 are the cables themselves as Walt just suggested.
And then #7 would be the battery itself. There could be a broken plate in there causing a dead short or simply disconnecting one of the terminals internally.
At your next dead cycle, measure the voltage across the battery at the battery. Then check continuity between battery positive and the starter and then from negative to a good frame ground....... all without jostling the car at all.
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

Lexi

#14
Put in a 10 hour day today, but think I finally chased the last of these gremlins away. Larry was apparently correct in that the problem was on the + side of the system. Those 2 mysterious butt-connected wires half way up the firewall proved faulty. One was the ballast resistor coil side wire which was moving inside the connector. Not good. Jacking car caused wire movement in the right direction to temporarily 'correct' the problem. Other wire I believe was the NSS one which was also a little loose. A (replaced) ring connector then fell off at the respective solenoid terminal. All connectors changed and soldered and sealed with heat shrink. Someone has changed all these wires colors, but I believe these 2 were the culprits, with a 3rd suspect wire (changed that as well). I also added the 2nd firewall ground strap as it was missing.

Last time this starting/running problem happened it was my frame ground but seems I did fix that properly 2 years ago. I now have some research to do as it appears my Series 75 may have a different frame configuration; and that large sheet metal screw in that impossible place on top of the frame rail may be the correct spot for it after all, (as Larry also indicated). Afterall, how could anyone even drill a hole there (or want to)? Indeed, a stupid place for the ground strap frame connection.

A word of advice for those looking for tips on wire repair in this solenoid/firewall bundle area: 1) Pull them all up to the engine bay area to work on them. For those wires that need replacing you can do a lot of the work on the bench. MUCH easier that way. 2) Always refer to the various CLC Forums for tips and great advice. 3) Don't assume the wiring diagram is accurate; as I earlier reported in the Mid Century Forum that the '56 diagram showed a wrong color for a wire running from the NSS to ignition switch for example, (yellow wire proved to be a violet one). Later confirmed by two senior members. Thanks to all and now that my car is no longer 'house broken' , it is now 'house trained' (at least for now)! Keeping my fingers crossed. Clay/Lexi

Jeff Rosansky CLC #28373

Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

Lexi

Jeff thanks for your input, (have tucked your suggestions away for future reference). Transient problems such as this can be tough to troubleshoot. Nice to know there is a 'life line' on this Forum. Now it looks like I can do this Caddy show this weekend. Thanks again to all. Clay/Lexi

cadman56

Awesome news Clay.  Yeah, that is a bad place.  Lots of heat and oil vapors.
Now to figure out what is wrong with my car.  I might start a thread if I can't get it tomorrow, want to check out a couple of educated guesses first.
Great news.  Now get out there and blow the cobwebs out of it.  :-)
Larry
1956 Cadillac Coupe deVille (sold)
1956 Cadillac Convertible (sold)
1956 Cadillac Eldorado Seville (sold)
1967 Cadillac Eldorado (sold)
1968 Cadillac Convertible (Sold)
1991 Cadillac Fleetwood Brougham dElegance
Larry Blanchard CLC #5820

Jeff Rosansky CLC #28373

You're absolutely right. This forum is a lifeline. I have had help solving some doozies. And, I admit when I am dumb because I bet (hope) somebody has done the same and/or may learn from my mistakes.
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

Lexi

#19
Jeff that is so right on. And yep I was wrong about the ground issue. I should have had more confidence in the repairs I made to that a couple of years ago. I agree that there is a wealth of information on this Forum. Usually members point me in the right direction or even flat out solve a riddle for me. Best of all I always find their advice inspiring as it encourages me to resolve such issues usually on my own. It is a rewarding and educational experience. Now, if Larry still has problems hopefully he will start a post tomorrow! Good luck there Larry and do drop us all a line if you are stuck! Clay/Lexi