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I'm not sure if I'm having a battery issue or if there is something else with the charging system on my '86 Monte Carlo. I normally get six years or so on a new battery ( AC Delco ), last April, I replace it. During the winter months / storage , I remove the battery cables...when I'm ready to start it, I'll hook up the cables and place the Battery Tender on it. Once I have the steady green light on the Battery Tender, the car would always start right up - but not this time. So I hooked up my old Diehard Battery charger, switch it over to the 50amp starter mode.... nothing. I switched the mode over the 10amp and let the battery sit for the day and let it charge...still nothing. The under hood light comes on, interior lights come on... is there something else that I should be looking at? 

 

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We need a bit more info. When you say "nothing", exactly what do you mean?  You say you have under hood and interior lights, so not absolutely nothing.  I assume you mean nothing when you turn the key. Is there anything on the dash when you turn the key on? Idiot lights, gauge movement etc....  Assuming just no starter action, the most likely areas are rodent damage to wiring, ignition switch (key) and if automatic transmission, the neutral safety switch, if manual transmission possibly a clutch safety switch.  Let us know...

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6 minutes ago, 37_Roadmaster_C said:

I assume you mean nothing when you turn the key.

Exactly. Nothing on the dash regarding idiot lights / gauge movement....It's a HO 305 V8 with the automatic transmission... it's a low mileage car that's been covered and stored correctly since I purchased it back in 1986. I'll check the wiring tomorrow before heading off to work if I have time.

Thanks !

 

 

047.JPG

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Battery needs a load test to best check it.  Sometimes they can power low draw bulbs etc and die when big amps are needed.  If the battery checks good then it’s off to other things.

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Ok, with no dash indication you can forget the safety switches. The wiring is still a possibility. The ignition switch is a high point, but now a fuse seems like the first thing to check. It seems strange that a fuse would blow after proper storage, but who knows.  With the hood and interior lights working there is power to the fuse block, so main wiring is clear. Check fuses and let us know...

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Troubleshooting 101.

 

First question is, what is working?  Underhood and interior lights mean that you have SOME batter power on SOME circuits. What else works? Headlights? Horn? Brake lights when you step on the pedal? That will start to narrow it down. My money says that the battery is fine.

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19 minutes ago, joe_padavano said:

What else works? Headlights? Horn? Brake lights when you step on the pedal?

Joe - just checked the horn, brake lights and headlights.... all work.  Just strange... after 35 years of ownership, never had this happen...

 

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So you're getting power to the fuse box. There's a red power wire with a fusible link running from the starter to the fuse panel. This wire feeds both the "always hot" fuses like the dome and stop lights and also feeds the ignition switch. There's a splice in the harness where this splits off. If that splice has gone bad, that's one potential cause. Start by testing for power on the two red wires in the ignition switch connector. They should be hot at all times. If not, suspect that splice. If they are hot, it sounds like the ignition switch.

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Assuming you have power on the red wire to the ignition switch, check for power on the pink wire in that same connector when the switch is in the RUN position. That's the wire that powers the ignition and gauges. Similarly, the purple wire in the ignition switch connector should have power with the key in the START position. This is what powers the starter solenoid.

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2 hours ago, 37_Roadmaster_C said:

Ok, with no dash indication you can forget the safety switches.

 

You can forget the neutral safety switch in any case - there isn't one on this car. GM did away with an electric NSS in the late 70s. There's a mechanical blocking system in the steering column that physically prevents the key from turning to START unless the trans is in PARK or NEUTRAL. The switch at the base of the steering column that looks like an NSS is only for the backup lights (and to signal the ECU for PARK/NEUTRAL on computer controlled cars). It is not wired into the starting curcuit in any way.

Edited by joe_padavano (see edit history)
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1 hour ago, joe_padavano said:

 

You can forget the neutral safety switch in any case - there isn't one on this car. GM did away with an electric NSS in the late 70s. There's a mechanical blocking system in the steering column that physically prevents the key from turning to START unless the trans is in PARK or NEUTRAL. The switch at the base of the steering column that looks like an NSS is only for the backup lights (and to signal the ECU for PARK/NEUTRAL on computer controlled cars). It is not wired into the starting curcuit in any way.

 

Thanks for the education @joe_padavano.  I have never had to dig into that area of my 1980 and newer GM products. My 97 GMC still has a clutch safety so I just ... well that assume thing 😂.

 

@STEVE POLLARD, I am going to step back, but not out!  Joe has much more knowledge about your vintage and model of car than I do.  I will chime in if I see somewhere I may help. Good Luck and keep us posted!!!!

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2 minutes ago, misterc9 said:

Did you try tapping the starter while someone holds the key in the start position?

That was always my dad’s first response, I even think he had special a ball peen hammer he liked best for tapping it.

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Most or all of the underdash wiring (non-computer) passes through the firewall by way of the bulkhead connector. On your 1986 Monte Carlo, this big square connector is probably located below the brake booster. One small bolt in the center (engine side) holds the male & female halves together. After 35 years, a small amount of oxidation may have formed on the brass terminals. It may be just enough to cause a voltage drop at the starter solenoid. There will be dried out dielectric grease covering the inside of the connector. 

 

I would suggest that you disconnect the negative battery cable, loosen the bolt, separate the halves, and then carefully reconnect. Disconnect and reconnect a few times and attempt to start the engine.

 

After 24 years, the headlights on my 1984 Toronado (owned since new), wouldn't turn on. After some testing, I decided to look into the bulkhead connector. "Breaking and making" those connections solved the problem. While I had the connector open, I cleaned out the old dried dielectric grease and reapplied new grease.

 

There isn't lots of room in that firewall area so be prepared to cuss a lot...!

 

I kept my Toronado for several more years and the headlight issue never returned. 

 

Please keep us posted.

 

Paul

Edited by pfloro (see edit history)
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Steve,

   Did you do the headlight test?  Turn on the headlights and try to start the car.  If the headlights go dim, it is your battery.  If the headlights stay bright it is your starter.  This is a pretty common GM car, do you have another good battery to try?  I would start by cleaning the battery cables, this happens to me annually.  My money is on the battery connections.  I do like the checking the sandwiched wire connectors and cleaning them also.  You did not tell us if you drove the car into the storage area, or was the battery new after you parked it?  

 

I think is it something simple, neutral control switches usually die slowly.  You might try disconnecting the battery and cycling the ignition switch a few dozen times, sounds stupid but sometimes the contacts gum up, just fixed one last year by doing this, it was not a GM car.

 

Good luck

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I'll keep you guys posted.... I work a 12hr over night schedule, my rotation will be done Wednesday morning, so I'll look into it again Wednesday afternoon..... 

 

Thanks for all the input !

 

Steve

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Steve,

Start with Joes suggestions about checking for power on the wires to the ignition switch. The fact that you do not get any dash response, idiot lights and/or gauge bumps, while the lights work clearly points to a power problem in the switch circuit. There are very few things that can cause this and Joes troubleshooting procedure is right on.

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On 3/7/2021 at 11:31 PM, Graham Man said:

This is a pretty common GM car, do you have another good battery to try?

So before I did anything, I went ahead and took the battery from my everyday driver ( 2007 GMC passenger van ) and installed it in the Monte Carlo.  The car started right up !  I don't understand how a brand new battery ( 11   mos. old ) would have the charging issue ? 

 

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The battery may have been stuck somewhere in the supply chain and was damaged by sitting without being charged. Lots of other possibilities but I would bet on that one.

 

Dave

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Over the years I had two that did that. They would run small loads but died when the starter draw kicked in.  At least it’s not a big trouble shooting episode (this time).  Good news!

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Occam's razor..............Occam's razor is the principle that, of two explanations that account for all the facts, the simpler one is more likely to be correct.............Bob

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Maybe. Battery warrantees aren't worth a hoot any more.

 

There should be a stamp or sticker on the battery that shows date of manufacture. The battery may have been a year or more old when you bought it. 

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If you bought another ACDelco they have a good free replacement period depending on the battery series. You could get a free replacement.

 

Dave

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On 3/10/2021 at 7:32 PM, Dave39MD said:

If you bought another ACDelco they have a good free replacement period depending on the battery series. You could get a free replacement.

Just returned from the Dealership.....new battery, no charge !

 

 

Steve

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On 3/7/2021 at 9:17 AM, STEVE POLLARD said:

During the winter months / storage , I remove the battery cables...when I'm ready to start it, I'll hook up the cables and place the Battery Tender on it. Once I have the steady green light on the Battery Tender, the car would always start right up - but not this time. 


Steve, was the battery tender hooked up to the battery over winter/storage or only when you proceeded to wake it from its slumber?

 

Interested in your answer, given that I have had great results using battery tenders 24/7 while the two Buick’s are idle.
 

One has a battery isolator, the other I disconnect the positive cable. Sure, a little mucking around to remove the leads whenever you want to use them, but so far the batteries have not been a problem. Before installing the new correct size battery in the Skylark, it went on the tender overnight to fully charge before use.

 

From what I read on these forums, new batteries like to be fully charged all the time and seem to fail earlier when allowed to remain discharged or not used. 
 

As mentioned, interested in your answer.

Rodney 😀😀😀😀😀😀

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2 minutes ago, rodneybeauchamp said:

Steve, was the battery tender hooked up to the battery over winter/storage or only when you proceeded to wake it from its slumber?

Rodney - the battery tender was not hooked up during winter storage...I've never had an issue over the last 35 years, always disconnected everything.... this was the first time I had an issue with a new battery.

 

Steve

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