Latched relay explained
- Thread starter mikefamig
- Start date
That is the same symptom that I had when the problem began and it's very very common to the old gm cars. Just google chevy won't start when hot. The solenoid wouldn't activate when the car was hot but would start when the car cooled off. Eventually the car would not start at all.
The wiring harness between the battery and the solenoid had some design problems that caused corrosion over time which in turn caused voltage drop to the solenoid. When the solenoid gets hot it requires more power to activate it than when it is cool. This is because the resistance in copper wire increases with temperature and the solenoid is a large winding of copper wire. The combination of these two things causes the failure.
I spent days cleaning connections and replacing brittle wires and the problem lessened but still occurred when the car was hot. In the end the solution was to use a lighter return spring in the solenoid. The car has been good for about a year now.
If your friend has troubles with the new starter I can give him some tips on where problems occur in the wiring and they should be cleaned up but the real solution was to use a lighter spring in the solenoid.
Mike.
The wiring harness between the battery and the solenoid had some design problems that caused corrosion over time which in turn caused voltage drop to the solenoid. When the solenoid gets hot it requires more power to activate it than when it is cool. This is because the resistance in copper wire increases with temperature and the solenoid is a large winding of copper wire. The combination of these two things causes the failure.
I spent days cleaning connections and replacing brittle wires and the problem lessened but still occurred when the car was hot. In the end the solution was to use a lighter return spring in the solenoid. The car has been good for about a year now.
If your friend has troubles with the new starter I can give him some tips on where problems occur in the wiring and they should be cleaned up but the real solution was to use a lighter spring in the solenoid.
Mike.
pete_c
Guru
He is stubborn. I told him about your starter issues and why.
He just bought a new starter (refurbished) from an automotive big box store. I doubt very much that they fixed the design of the starter.
I have purchased automotive products from same big box store and they typically come up with some reason to change your warranty on their product after a month or two (willy nilly business practices)...I went to on line...(still had one issue with one product...)
When helping me last year and the car not starting he said it was relating to his new battery not getting a charge from his new alternator as the car was idling for 20 minutes, then he shut it off, then it didn't start until it cooled off. We didn't jump the car. He is older (just about 70 now) and prefers these day just to drive the car and not to do anything to it...
He just bought a new starter (refurbished) from an automotive big box store. I doubt very much that they fixed the design of the starter.
I have purchased automotive products from same big box store and they typically come up with some reason to change your warranty on their product after a month or two (willy nilly business practices)...I went to on line...(still had one issue with one product...)
When helping me last year and the car not starting he said it was relating to his new battery not getting a charge from his new alternator as the car was idling for 20 minutes, then he shut it off, then it didn't start until it cooled off. We didn't jump the car. He is older (just about 70 now) and prefers these day just to drive the car and not to do anything to it...
I'm 62 now and know the feeling. When I lay on the ground it's not so easy to get back up again.
There is a permanent and inexpensive fix if he is not worried about keeping the car all original. A lot of guys just install a Ford type starter relay switch which switches with much less power than the GM solenoid. It works like a charm and probably wouldn't cost too much to have a mechanic do it for him if he can find one that knows how to do it.
There is a permanent and inexpensive fix if he is not worried about keeping the car all original. A lot of guys just install a Ford type starter relay switch which switches with much less power than the GM solenoid. It works like a charm and probably wouldn't cost too much to have a mechanic do it for him if he can find one that knows how to do it.
That was going to be what I was going to say.....the remote solenoid solution, couldn't remember which of the big 3 parts were used and the relocation off the starter motor.mikefamig said:
Also not a great location for the solenoid, especially if headers were installed on a GM small block. Same reason why a lot of guys use the smaller high torque starters (think they're off foreign cars then rebuilt/remanufactured for the smallblocks.
Pete
Here is a link to a GM Delco starter.
https://www.amazon.com/ACDelco-337-1016-Professional-Starter/dp/B007QBSYHC/ref=sr_1_3?s=automotive&ie=UTF8&qid=1468154808&sr=1-3&keywords=delco+starter
The large unit on the bottom is the starter motor and the smaller cylinder sitting on top is the solenoid switch. The solenoid is a combination relay and electromagnetic switch. When you turn the ignition key current is supplied to the relay which switches closed and energizes the starter motor and an electro-magnet that mechanically compresses a spring engaging the motor drive gear with the flywheel on the engine. When you release the key switch the relay opens which de-energizes the starter motor and the magnet and the drive gear disengages from the flywheel by means of a spring that pushes it back towards the relay..
The problem arises when you turn the ign key and there is a voltage drop to the solenoid/relay and the magnet does not energize. If you look at the solenoid you'll see that it is a pretty large cylinder. In the end of that cylinder is a winding of copper wire. When the engine heats up the impedance in that winding increases and in turn requires more electric power to energize it than when it is cold. So the end result is that there is just enough power for the solenoid to work cold but not enough when hot.
There are three things that you can do to make the system work again.
1 Make sure that you have a good fully charged battery
2 reduce the voltage drop by cleaning and repairing all electrical connections between the battery and the solenoid.
3 Install a solenoid that requires less power to energize
4 Install a lighter return spring so that the solenoid can overcome it's resistance easier.
Here is a link to a GM Delco starter.
https://www.amazon.com/ACDelco-337-1016-Professional-Starter/dp/B007QBSYHC/ref=sr_1_3?s=automotive&ie=UTF8&qid=1468154808&sr=1-3&keywords=delco+starter
The large unit on the bottom is the starter motor and the smaller cylinder sitting on top is the solenoid switch. The solenoid is a combination relay and electromagnetic switch. When you turn the ignition key current is supplied to the relay which switches closed and energizes the starter motor and an electro-magnet that mechanically compresses a spring engaging the motor drive gear with the flywheel on the engine. When you release the key switch the relay opens which de-energizes the starter motor and the magnet and the drive gear disengages from the flywheel by means of a spring that pushes it back towards the relay..
The problem arises when you turn the ign key and there is a voltage drop to the solenoid/relay and the magnet does not energize. If you look at the solenoid you'll see that it is a pretty large cylinder. In the end of that cylinder is a winding of copper wire. When the engine heats up the impedance in that winding increases and in turn requires more electric power to energize it than when it is cold. So the end result is that there is just enough power for the solenoid to work cold but not enough when hot.
There are three things that you can do to make the system work again.
1 Make sure that you have a good fully charged battery
2 reduce the voltage drop by cleaning and repairing all electrical connections between the battery and the solenoid.
3 Install a solenoid that requires less power to energize
4 Install a lighter return spring so that the solenoid can overcome it's resistance easier.
The added Ford type relay that I mentioned earlier replaces the circuit between the battery and the solenoid with a more direct route. You take a wire from the battery to the relay and then directly to the solenoid in a very direct route with very little voltage drop. That new relay is then triggered by the original key switch circuit that was not powerful enough to trigger the original solenoid but is more tha n powerful enough to trigger the new relay.
On my old Camaro with V8 engine it is hard to see the starter because it is on the right side of the engine hidden by the exhaust manifold.
On my old Camaro with V8 engine it is hard to see the starter because it is on the right side of the engine hidden by the exhaust manifold.
pete_c
Guru
I will ask and take pictures of the engine.
A couple of weeks back he stopped by and we talked a bit about getting the Spitfire running in the next few weeks.
The car came from his family's car collection. His family had built a facility to house and display his collection of cars. Family owned an indoor golf course in downtown Chicago.
Friend was given the vehicle in the 1990's. It had sat for a while in the facility and it was redone a bit. (painted from scratch et al).
Well one day his brother in law was testing a new (old) acquisition (youngest brother in law) GM Corvette and overestimated what it could do and destroyed the vehicle and himself sometime in the middle 2000's.
A couple of weeks back he stopped by and we talked a bit about getting the Spitfire running in the next few weeks.
The car came from his family's car collection. His family had built a facility to house and display his collection of cars. Family owned an indoor golf course in downtown Chicago.
Friend was given the vehicle in the 1990's. It had sat for a while in the facility and it was redone a bit. (painted from scratch et al).
Well one day his brother in law was testing a new (old) acquisition (youngest brother in law) GM Corvette and overestimated what it could do and destroyed the vehicle and himself sometime in the middle 2000's.
