sredmyer Posted October 7, 2017 Share Posted October 7, 2017 So I had one of my cars out for what is likely the last time this year. After driving some beautiful country roads for about an hour I stopped at a convenience store to get a drink. When I got out of the store and went to start the car and leave, it would not start. I turn the key but nothing happened and by nothing, I mean nothing...no click no nothing. It was like the car was not in park so I shifted into gear then back to Park but still nothing. I turned on the lights and had my wife watch them while I turned the key and they did not dim at all so the starter is obviously not being energized. Sounds like the neutral safety switch but wait... This actually happened once before. The car was hot after some long country road (read slowish) driving and I stopped at a friends house. When I went to show him the car and start it up, same thing, no start. I was planning to visit with my friend so I didn't worry much about it at the moment and figured we could look at it later when I was ready to leave. When I came out some time later to leave the car started right up. I ended up having the same luck this most recent time, after waiting a bit for the car to cool it started right up. So the car acts like the neutral safety switch is bad when it is hot, but give it time to cool down and it starts right up. Can anyone suggest what might be going on? Can the neutral safety switch be going bad in this way...affected by heat? Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted October 7, 2017 Share Posted October 7, 2017 Voltage drop is key. I have found that if you measure voltage at the violet color wire in the engine bay, while your fault is present. The wire going straight to the solenoid, after the NSS. You'll find out two things the voltage and wether it's originating after the neutral safety switch. If you have a strong 12v and the start sequence is not present, I'd say solenoid or stater related. Assuming good ground..if no or little voltage at wire, ign switch, NSS, or the old fusible link in engine bay. The key here once again is voltage drop. Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted October 7, 2017 Share Posted October 7, 2017 The most common condition I have ever found is a lack of 12v to the ignition switch, guess where that wire originates from, that poorly designed link coming across the radiator support from the battery to the horn relay, via fuseable link to ign switch. Speaking here on '70 year related. Quote Link to comment Share on other sites More sharing options...
sredmyer Posted October 7, 2017 Author Share Posted October 7, 2017 Ok, what is NSS Quote Link to comment Share on other sites More sharing options...
72-CLASSIC_RIDE Posted October 7, 2017 Share Posted October 7, 2017 Ok, what is NSS Neutral Safety Switch.................. Plus I had an ongoing issue with weak engine cranking when engine got hot. I shielded the Starter but still turned over like the battery was weak but eventually would always start. This was after addition of a new Delco heavy duty Starter. What ultimately happened was I gave the problem to a Shop who replaced the Ground Battery Cable and Battery Post with a more robust cable/connector. He also fine tuned my timing. He claimed that the cable did not have the ability to transfer the power needed from the battery (when engine hot) to the Starter. A simple explanation for a more complex problem. But never had another issue since. Doug Quote Link to comment Share on other sites More sharing options...
1970mcss Posted October 8, 2017 Share Posted October 8, 2017 I had the exact same thing happen last weekend. When I jumped the car it started right up. The prior owner had put on a fuse in place of the fusible linkIand the wire connection ant the cable was a bit flakey. I replaced the positive cable, fusible link and have ordered a new negative cable. I hope that fixes my problem. One question I have is what should the amp guage read when running? Quote Link to comment Share on other sites More sharing options...
sredmyer Posted October 8, 2017 Author Share Posted October 8, 2017 Voltage drop is key. I have found that if you measure voltage at the violet color wire in the engine bay, while your fault is present. The wire going straight to the solenoid, after the NSS. You'll find out two things the voltage and wether it's originating after the neutral safety switch. If you have a strong 12v and the start sequence is not present, I'd say solenoid or stater related. Assuming good ground..if no or little voltage at wire, ign switch, NSS, or the old fusible link in engine bay. The key here once again is voltage drop. Doesn't the test I did of turning on the lights and attempting to start accomplish the voltage drop test you are talking about? The idea is that if the starter/solenoid are getting power there should be a significant dimming of the lights when the ignition switch is turned to the start position. If there is no dimming (which there was not) then there is no voltage drop. Since there was no voltage drop I think it has to be either the ignition switch, NSS or the fusible link you mentioned but it just doesn't makes sense to me that any of those would be affected by the temperature of the car. Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted October 8, 2017 Share Posted October 8, 2017 Voltage in fact is affected by temperature. Though your test of looking at the headlights to dim is a valid one. Yet the lights could also dim and still no crank condition. I believe the field in the starter solenoid requires a minimum voltage to pull the plunger. Quote Link to comment Share on other sites More sharing options...
cbolt Posted October 8, 2017 Share Posted October 8, 2017 Just to clarify, voltage in and of itself is not affected by temperature, however the conductor material is affected by temperature. I'm an electronics nerd, sorry. Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted October 8, 2017 Share Posted October 8, 2017 I guess to put in better terms, I suppose. Similarly when a battery is exposed to low temperatures, it behaves much better warm. Quote Link to comment Share on other sites More sharing options...
MCfan Posted October 9, 2017 Share Posted October 9, 2017 Steve, As I understand the symptoms you have encountered more than once, it surely sounds like you have adequate voltage (V) in the starter circuit so I suggest you focus on the other side of Ohm's Law (V=I*R), especially since your battery is obviously strong enough (sufficient voltage and amperage) to start the engine under specific temperature conditions. The starting circuit is not delivering electrical power (P=V*I or P=I*I*R) at the starter. It sure sounds to me like you are dealing with a circuit conductivity issue affected by high temperature. Simply put, either the starting circuit is intermittently opened by high temperature (allowing no current flow) or resistance ® in the circuit is so high (possibly due to corrosion, damaged wire or loose connection) that current (I) is too low to engage the starter solenoid. Since the wire sizes in the circuit are obviously adequate to start the engine when it the circuit is cool enough, the NSS is working and the fuses are good, it almost has to be a loose or corroded connection in the circuit or a damaged conductor. I have experienced the exact symptoms on both a Jeep and a Lexus and both times it was as simple as removing the battery cables from the battery, cleaning the corrosion off and tightening them securely to the battery posts. A loose connection elsewhere in the circuit (i.e. at the solenoid or starter), especially one that is down by the exhaust header, is also a prime suspect. A linear starter solenoid requires a threshold current to create enough electromagnetic force to overcome the force of the bendix return spring but your starting circuit is apparently not seeing that at high temperature because you are hearing nothing during failure. I suggest you clean and tighten all of the connections at the battery, solenoid and starter. I also suggest you inspect every inch of the wiring in the circuit for crimps, cut wires in the braided cable and/or missing/burned insulation. If any of the wiring is laying against surfaces that get really hot during operation, tie them back, reroute them and/or apply some thermal insulation. Sorry I can't give you any "whack it here" advice but those failure symptoms would cause me to look beyond low voltage as the probable root cause. Good luck. 1 Quote Link to comment Share on other sites More sharing options...
LS5 Posted October 9, 2017 Share Posted October 9, 2017 Just to clarify, voltage in and of itself is not affected by temperature, however the conductor material is affected by temperature. I'm an electronics nerd, sorry. The resistance of a wire also increases with the temperature of the wire because as temperature increases, the electrons begin to move faster and collide with each other more, thereby causing resistance to increase. basically.......... Darren Quote Link to comment Share on other sites More sharing options...
MCfan Posted October 9, 2017 Share Posted October 9, 2017 The resistance of a wire also increases with the temperature of the wire because as temperature increases, the electrons begin to move faster and collide with each other more, thereby causing resistance to increase. basically.......... Darren Right on, Darren. And the opposite is also true, lower temperatures reduce resistance even to the point where superconductors have zero electrical resistance. Ohm's law says Current (I) = Voltage (V) divided by Resistance ®. Even if +12V is present, in a circuit with high resistance ®, the available current (I) will be reduced, possibly below the level needed to energize the starter solenoid. Not possible to disobey the laws of physics ... When I replaced the long tube headers that ran very close to the starter on my 402 with a set of 3/4 length headers last spring, it completely eliminated the sluggish starter action when the car was hot. A wire in the starting circuit that is laying against a hot manifold or header pipe will greatly reduce the current available to the starter. Quote Link to comment Share on other sites More sharing options...
sredmyer Posted October 10, 2017 Author Share Posted October 10, 2017 While this physics lesson is very interesting I seriously doubt it has anything to do with my problem. I seriously doubt the resistance change due to temperature would be significant enough in just a few minutes (less than 15) to go from absolutely nothing when turning the key to starting fine. Quote Link to comment Share on other sites More sharing options...
MCfan Posted October 10, 2017 Share Posted October 10, 2017 While this physics lesson is very interesting I seriously doubt it has anything to do with my problem. I seriously doubt the resistance change due to temperature would be significant enough in just a few minutes (less than 15) to go from absolutely nothing when turning the key to starting fine. Possibly a loose or corroded connection ... or maybe your Monte's just messin' with ya! Good luck. Quote Link to comment Share on other sites More sharing options...
stangeba Posted October 11, 2017 Share Posted October 11, 2017 I remember one time when my 71 wouldn't crank. I hit the starter mtr with a hammer and it cranked and started fine. Went home and pulled the original starter, brushes were worn out, replaced them $5.00, good to go for 15+ years. Next time it happened I removed the original starter and took it to a shop that repairs starters and alternators, they replaced the solenoid but said the only thing wrong was a part inside that looks like a big thick washer, was burnt at the contact areas. He said he could just rotate this washer and it would be fine. Again, I really don't like "rebuild starters" fix what you have if possible and NEVER turn in the core. Bruce Quote Link to comment Share on other sites More sharing options...
Dito707 Posted November 13, 2017 Share Posted November 13, 2017 Hey I had almost the same problem drove my 70' Monte to the store then it wouldn't start, but it started to crank then stoped cranking and u could hear the starter humming like "vvveeeeeevvv" noise, is my my starter bad or is it the solenoid? Thanx for any help, also what's the easiest way to remove the starter? I've never takin one out before Quote Link to comment Share on other sites More sharing options...
cbolt Posted November 13, 2017 Share Posted November 13, 2017 Disconnect the negative battery terminal. Raise the passenger side of the vehicle and support it on either jack stands or ramps. From under the passenger side remove the two starter bolts, I think they are 1/2" but could be 9/16", I don't remember top of my head. Slide the starter forward until the drive gear housing clears the transmission cover (You may have to remove the cover) Slide the starter out the bottom far enough to get access to the wires on the solenoid, and then remove the nuts holding the wires to the solenoid paying attention to the location of the wires. Viola! The starter is out. Installation is the reverse of removal. Quote Link to comment Share on other sites More sharing options...
Dito707 Posted November 13, 2017 Share Posted November 13, 2017 Cbolt thanx alot! Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted November 16, 2017 Share Posted November 16, 2017 My Monte has has giving me starting issues this year though it's 99% due to an old battery. Pulled the battery from a wrecked car back in 2010 or 11. No idea how old it was then. This year it's been starting very hard and as the cold started coming in failing to start at all. Put my charger on it and even when it reads full, nothing more than maybe half a revolution. Tried boosting off my truck with no effect. Ultimately I disconnected the battery and cleaned the terminals and tried again. Nothing. What actually worked was removing the side posts from the cables and using jumpers right to the cables, boosting off my truck. Fired up really strong. Let it run for a minute while I moved my truck out of the way and when I went to leave the driveway in the car I stalled at the end. Wouldn't start! Time for a new battery? Quote Link to comment Share on other sites More sharing options...
72-CLASSIC_RIDE Posted November 17, 2017 Share Posted November 17, 2017 Time for a new Battery............................. Doug Quote Link to comment Share on other sites More sharing options...
71MonteCarloMD Posted December 16, 2017 Share Posted December 16, 2017 Was wondering about this as I had this issue after driving on hot day, now I know what to do - replace my cables Quote Link to comment Share on other sites More sharing options...
Steve B Posted March 22, 2021 Share Posted March 22, 2021 I’m having the same issues as the gentleman submitted below ( exactly the same issue). Can anyone tell me what the problem maybe on my 70? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.