Need help - 56 Buick Super cuts out unexpectedly

[Guest gksullivan]

I'll be driving down the street and all of a sudden everything goes completely dead. But, if I immediately shift into neutral, it will start immediately and run as if nothing happened. By dead I mean engine stops, radio goes off, brake lights/turn signals go off, etc. It's like someone unhooked the battery. This started only recently but now happens maybe twice in a half hour trip. The battery is fully charged, engine runs strong. I do not have to juggle the ignition switch or the neutral safety switch to get it working again but I guess it could be one of those? I recently upgraded to xenon bulbs but this happens day or night. The only thing I can figure is that the added amps from the new xenon lights have made the thermal breaker in the headlight switch weaker. That would explain the headlights, tail lights, parking lights, license and instrument lights going out but not the radio or the ignition. Any ideas? Thanks Gael

[old-tank]

I hate intermittent problems. Unless it dies an stays dead it is hard to find. In the meantime check all connections (especially at the battery, voltage regulator, terminal block, etc) and grounds (there should be a ground from the engine to body...my 55 has one at the transmission filler to the firewall). It could be a completely open connection or a a dead short. The last one of mine that did this died mostly on right hand turns...the problem was the starter splash pan shorting to the largest cable on the solenoid.

Willie

[Smartin]

I would look at the starter area for a loose connection on one of the wires. There aren't too many things that can completely kill the entire car...should be related to ignition power somehow...possibly a fusible link?

[trp3141592]

Hi,

I would look at the starter area for a loose connection on one of the wires.

Your symptoms are exactly what the symptoms were with my '37. I found that the primary cable from the battery was loose at the starter terminal. Tightened the nut, problem was gone.

--Tom

[buick man]

But if it then starts right up in neutral it would not be your battery to starter cable as being loose unless the linkage is pushing on the cable so when you shift up to neutral it moves the arm up and binds against the cable which serves to tighten the connection enough for a successful start. Then when back in drive the cable is free to vibrate loose just enough to prevent starting. With this said, I am assuming you have a direct cable run from the battery positive terminal straight down to your starter solenoid with no resistor or terminal blocks in between. But if you do have terminal blocks in between, then your problem is at that point where any and all current can be routed before the starter and switch runs. If you have a positive or negative post disconnect shut-off switch mounted at near the battery, this can also cause these types of problems as well. So get under there and check all cables. Block your tires and have someone move the shifter from drive to neutral and back to see what gives.

[Guest gksullivan]

Thanks for the replies, much appreciated! Before I posted I went through the electrical system using the circuit diagram in the manual and everything is tight but didn't get underneath to check the starter cables and dynaflow control arms. Will do that this afternoon. David may have id'd the problem - I do have one of those "screw down" disconnect switches on the negative side of the battery. Will remove that for sure! One thing that I have noticed is that this does not happen when the car is jarred as it hits something rough on the road... It has happened while on smooth road going maybe 35 or 40 and once about 5 seconds after taking off from a start. It's like there was a thermal circuit breaker in the battery cable that senses a brief over-current situation, shuts down which alleviates the problem and immediately resets so I can start the car. It takes me about five seconds to realize everything has shut down, to shift into neutral, push the accelerator to the floor to start it, shift back into drive and continue on as if nothing had happened. Any other ideas let me know. Could this be an ignition or neutral safety switch problem?

[bhambulldog]

I agree with the other's ideas

But, it also occurred to me that it could a problem inside the column. A problem with the wiring of the safety switch

[Guest gksullivan]

So yesterday I checked the starter/solenoid wiring, solid as a rock, no dynaflow linkage interaction problems. Took off the quick disconnect from the battery, started the car and pulled on every cable I could see -- battery, those to starter/solenoid, one wire alternator, headlights, etc. Got in the car and jiggled the ignition switch and moved the gear selector in every way I could think of. Reached behind the dash and moved the wires behind the ignition switch and the steering column. Car did not shut off. Then I noticed the ammeter - was not charging. Odd as it had been charging the week before. Went over that wiring carefully, unhooked the alternator and tested it - no 12v (I did rev the engine enough to energize it so it should have come on). So I'll pick up a new alternator (this time a 3 wire so I won't have to rev to energize anymore) and will wire it in tomorrow. Rebuilt 63 amp Delco 10SI for $45. Anyone have tips about wiring in a 3 wire alternator? From what I can see on the web I need to add a feed from the ignition switch with a diode (and a resistor?) also one of the connectors needs to be hooked to the BAT terminal on the back. Maybe the old 1 wire alternator was causing the 'car dieing problem' but I can't imagine why....

[old-tank]

Alternator?! Now he tells us! There are threads on using a 3 wire alternator in early Buicks to work with the carb switch start feature...I'll search tomorrow if you cannot find. (Unless you have added a lot of high drain items, the stock charging system is more than adequate.)

Willie

[Guest gksullivan]

I am hopeful I've got all this sorted out. Thanks Willie for the heads up on the "keep the push gas to start feature." I found it and learned a lot about the unusual way the starter relay works. http://www.rowand.net/Shop/Tech/PushGasToStartWithAlternator.htm

I was surprised that the alternator had toasted at the same time as I was pushing and pulling on everything to try to make the entire electrical system shut down.

So I went ahead and replaced the one wire alternator with a three wire one, for many reasons especially that I do not need to rev the engine above about 1500 rpm to keep it active. The same website that discusses the "keep push gas to start" had lots of info as to how all this works and is a really good site. Go here: http://www.rowand.net/Shop/Tech/AlternatorConversions.htm Probably the best site is: http://www.madelectrical.com/electricaltech/delcoremy.shtml

So I got the alternator in, hooked up the battery and fired the engine. Everything worked fine.

But as I was reinstalling the ground cable from the battery I noticed something odd. The stud to which the cable had been hooked was loose. That was odd as it seemed to be an engine head bolt with a threaded stud to which the power steering pump bracket and the cable was hooked. It should have not been loose. I took the bracket off of the pump and found that what seemed to be a head bolt with a stud was actually a standard head bolt but someone had put another bolt through the hole in the bracket from behind. The battery was grounded through this bolt, the head of which was pushed against the head bolt as the upper end of the pump bracket was tightened. It was extremely corroded and obviously not creating a good ground path. I suspect that the car died as I was driving because what little was left of the bolt would mechanically lift off the head bolt, disconnecting the battery for an instant. I am hopeful that this has been the problem.... only time will tell.

Thanks for everyone's help! Gael

[JohnD1956]

That ground cable should go down to the drivers side engine mount, and attached with a nut and bolt in the extra hole in the engine mount. I will try to get a picture of mine tomorrow or the next day, if I can.

[buick5563]

JD is correct. Power steering cars had the ground clamp go to one of the bracket bolts.

[JohnD1956]

Here's the pictures: