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My '70 has thrown a couple of electrical issues in the last year or two that I have put aside until I got some motivation to investigate again! Its winter here so now I have more time to tinker.
I fitted LED daytime lights and within a few drives the LEDS started to fail, I replaced the lights with a different brand but the same thing happened, I suspected over voltage from the alternator but it measures at 14.8V. Could it be that it is spiking at times? I thought that the battery would clamp the Voltage and this would prevent spiking? At present I have no daytime lights fitted.
We were out cruising one day with the radio on and suddenly it started to act up. I tried to turn it off but the controls would not work. When we arrived home the only way I could turn it off was to disconnect the battery, when I reconnected the battery everything seemed normal except the active sub woofer was now permanently on instead of only powering up when the radio was turned on. Could this be related to the issue that affected the daytime lights?
The only other electrical issue I have had was the ammeter was showing a slight discharge when driving at night but this was remedied when I cleaned and tightened the alternator connection to the horn relay. Could the Voltage regulator in the alternator be causing an issue? I figured being electronic it was more likely to either be fine or completely dead not cause an intermittent issue. How is the birdcage grounded to the chassis? Could there be a problem with the grounds attached to the birdcage not being properly grounded to the chassis? If the birdcage is only grounded through the body bolts there could be an issue because whoever put the body one put the rubber bushes between the bolt heads and the birdcage instead of where I thought they should go - between the birdcage and the chassis.
Just thinking outside the box here. The other grounds I have cleaned and tightened the other main grounds and replaced the engine block to chassis one.
1.) Cannot help you on that one due to I have no clue on how it was wired up and anything related to it.
2.) Cannot help you for the same above reasons. No wiring schematic. It would only be guessing and wasting both of our time.
3.) AS for the ammeter. Not knowing if you have a higher amp alternator and if you stereo system takes lot of power...so hard to say. Not enough information
AS the way the birdcage gets grounded to the frame. There sis woven cooper cable strap that is screwed at the number 1 body on the drivers side...right there at the firewall area....and then the other end clips to the side off the rocker channel of your birdcage
1.) Cannot help you on that one due to I have no clue on how it was wired up and anything related to it.
LED lights were wired from fuse block so only on when key on, through an accessory switch to the lights and then to ground in the nose.
2.) Cannot help you for the same above reasons. No wiring schematic. It would only be guessing and wasting both of our time.
Radio wired from fuse block to head unit as per normal, signal wire from head unit to the active sub in the storage compartment. Power for sub fed direct from the battery via a fuse.
Stereo and sub,neither high-powered, sub unit is only a mini unit and the stereo about 40 wpc. Alternator is the original, has had bearings replaced by PO and maybe brushes but that would be about it.
3.) AS for the ammeter. Not knowing if you have a higher amp alternator and if you stereo system takes lot of power...so hard to say. Not enough information
AS the way the birdcage gets grounded to the frame. There sis woven cooper cable strap that is screwed at the number 1 body on the drivers side...right there at the firewall area....and then the other end clips to the side off the rocker channel of your birdcage
DUB
Hmm, don't ever recall seeing this strap, so I will start there, thanks DUB:-)
Last edited by Haggisbash; Jun 28, 2018 at 05:58 AM.
1.) LED LIGHTS: If I read what you wrote correctly You plugged into the Accessory port in the fuse panel. Being a 1970 Corvette with the old style glass fuses. I wonder IF that fuse BESIDE that ACCESSORY port is having problem because THAT is how the terminal is getting the power. I cannot tell you how many times I have to clean the terminals that hold in those type of fuses due to they get dirty and build up resistance when current it trying to get through it and they can cut out. Temporally re-wire it to a dedicated power supply even if it is a constant hot lead and see if they fail again.
BIRDCAGEGROUND: You will see a hole drilled in where a screw went on the mounting perch for the body mount where I described. If you look a t the ground strap kits for your car. You will see that strap because it is the ONLY one in the kit that has a clip on the end of it.
my '70 has thrown a couple of electrical issues in the last year or two that i have put aside until i got some motivation to investigate again! Its winter here so now i have more time to tinker.
i fitted led daytime lights and within a few drives the leds started to fail, i replaced the lights with a different brand but the same thing happened, i suspected over voltage from the alternator but it measures at 14.8v. Could it be that it is spiking at times? I thought that the battery would clamp the voltage and this would prevent spiking? At present i have no daytime lights fitted.
i would guess that you are getting voltage spikes. Leds like to be run at lower voltage and constant. You could get a voltage regulator/filter at a car audio store that you could try
we were out cruising one day with the radio on and suddenly it started to act up. I tried to turn it off but the controls would not work. When we arrived home the only way i could turn it off was to disconnect the battery, when i reconnected the battery everything seemed normal except the active sub woofer was now permanently on instead of only powering up when the radio was turned on. Could this be related to the issue that affected the daytime lights?
you probably have a aftermarket radio. The radio locked up so it would be your problem. If you are running the sub on switched power it can not change to steady power on its own unless it is a radio connection that has gone bad internally. If it does it again i would look at or replace radio
the only other electrical issue i have had was the ammeter was showing a slight discharge when driving at night but this was remedied when i cleaned and tightened the alternator connection to the horn relay. Could the voltage regulator in the alternator be causing an issue? I figured being electronic it was more likely to either be fine or completely dead not cause an intermittent issue. How is the birdcage grounded to the chassis? Could there be a problem with the grounds attached to the birdcage not being properly grounded to the chassis? If the birdcage is only grounded through the body bolts there could be an issue because whoever put the body one put the rubber bushes between the bolt heads and the birdcage instead of where i thought they should go - between the birdcage and the chassis.
just thinking outside the box here. The other grounds i have cleaned and tightened the other main grounds and replaced the engine block to chassis one.
1.) LED LIGHTS: If I read what you wrote correctly You plugged into the Accessory port in the fuse panel. Being a 1970 Corvette with the old style glass fuses. I wonder IF that fuse BESIDE that ACCESSORY port is having problem because THAT is how the terminal is getting the power. I cannot tell you how many times I have to clean the terminals that hold in those type of fuses due to they get dirty and build up resistance when current it trying to get through it and they can cut out. Temporally re-wire it to a dedicated power supply even if it is a constant hot lead and see if they fail again.
BIRDCAGEGROUND: You will see a hole drilled in where a screw went on the mounting perch for the body mount where I described. If you look a t the ground strap kits for your car. You will see that strap because it is the ONLY one in the kit that has a clip on the end of it.
DUB
Thanks DUB
I have some multi stranded welding cable and lugs left over from when I made a new engine ground strap, so I'll make up one for the birdcage to chassis:-)
I've been through cleaned the fuses and terminals before so I'm confident there is not an issue there.
You asked for help from those who are the 'gurus' as you called it. And I will just say this again that running a temporary by-pass to dedicated GOOD sources of power and ground to what you have as the set-up for your LED driving lights is something I would do to make sure I am not chasing my tail.
I have cleaned and cleaned fuses terminals and what appears to be GOOD still fails and will need to be cleaned again and again due to there is no way in being able to see how well the fuse actually is being griped to the terminal and how much of it is actually making contact.
Lastly...not knowing how many amps these LED's are pulling when on...I do not know what gauge of wire you used. Knowing that LED's generally do not draw a lot of amps...but...it also may be something to consider.
I thought that the battery would clamp the Voltage and this would prevent spiking? At present I have no daytime lights fitted.
If your alternator is over voltage due to a bad regulator the battery may bring down the voltage but it definitely won't cap/clamp the over voltage.
Originally Posted by Haggisbash
Could the Voltage regulator in the alternator be causing an issue? I figured being electronic it was more likely to either be fine or completely dead not cause an intermittent issue.
Bad regulators can cause low, high or fluctuating voltage (in addition to being completely dead.)
You asked for help from those who are the 'gurus' as you called it. And I will just say this again that running a temporary by-pass to dedicated GOOD sources of power and ground to what you have as the set-up for your LED driving lights is something I would do to make sure I am not chasing my tail.
I have cleaned and cleaned fuses terminals and what appears to be GOOD still fails and will need to be cleaned again and again due to there is no way in being able to see how well the fuse actually is being griped to the terminal and how much of it is actually making contact.
Lastly...not knowing how many amps these LED's are pulling when on...I do not know what gauge of wire you used. Knowing that LED's generally do not draw a lot of amps...but...it also may be something to consider.
DUB
Hi Dub, I appreciate your advice very much and will try your suggestion but,I have to get more lights first as the others are toast, I sent them back to the supplier (an auto electrician) for comment he stated that they were very reliable and he had not seen a failure like this before with them (he did refund my money also).
I may be overthinking this but a rapid failure of two sets of LEDs leads me to thinking that it could be a problem such as this?
Reverse bias: Although the LED is based on a diode junction and is nominally a rectifier, the reverse-breakdown mode for some types can occur at very low voltages and essentially any excess reverse bias can cause immediate degradation, and may lead to vastly accelerated failure. 5 V is a typical maximum reverse bias voltage specification for ordinary LEDs; some special types may have lower limits.
If your alternator is over voltage due to a bad regulator the battery may bring down the voltage but it definitely won't cap/clamp the over voltage.
Bad regulators can cause low, high or fluctuating voltage (in addition to being completely dead.)
Thanks Black04Vert. Given the low cost of a regulator I'm considering replacing it as a precaution, just because the Voltage was within tolerance when I checked it of course it could be fluctuating at other times.
1.) LED LIGHTS: If I read what you wrote correctly You plugged into the Accessory port in the fuse panel. Being a 1970 Corvette with the old style glass fuses. I wonder IF that fuse BESIDE that ACCESSORY port is having problem because THAT is how the terminal is getting the power. I cannot tell you how many times I have to clean the terminals that hold in those type of fuses due to they get dirty and build up resistance when current it trying to get through it and they can cut out. Temporally re-wire it to a dedicated power supply even if it is a constant hot lead and see if they fail again.
BIRDCAGEGROUND: You will see a hole drilled in where a screw went on the mounting perch for the body mount where I described. If you look a t the ground strap kits for your car. You will see that strap because it is the ONLY one in the kit that has a clip on the end of it.
DUB
Made a bonding strap and fitted it tonight, couldn't find one on the car so looks like it was never fitted when the body was put back on the chassis some time in the past, I know the body has been off because the through bolts in the transmission cross member were fitted the wrong way round and you can't do that with the body on!
From what I can tell. That cable is NOT grounding the birdcage. It appears to be going from the body mount to the frame. SO..in essence..it is doing nothing at all.
The cable needs to go from the body mount to where the yellow arrow is pointing.
The red arrow is pointing to where it is connected correctly...or any other place you know it is on the frame itself.
Reverse bias: Although the LED is based on a diode junction and is nominally a rectifier, the reverse-breakdown mode for some types can occur at very low voltages and essentially any excess reverse bias can cause immediate degradation, and may lead to vastly accelerated failure. 5 V is a typical maximum reverse bias voltage specification for ordinary LEDs; some special types may have lower limits.
AC voltage in your system will cause the LEDs to fail.... EVERY car with an alternator will have some AC in the system that gets through unfiltered. More than .5 volts will crate havoc on electronics. LEDs and electronics like nice clean DC...Have you checked for AC ripple? Really easy to do- and will keep you from chasing your tail.
AC voltage in your system will cause the LEDs to fail.... EVERY car with an alternator will have some AC in the system that gets through unfiltered. More than .5 volts will crate havoc on electronics. LEDs and electronics like nice clean DC...Have you checked for AC ripple? Really easy to do- and will keep you from chasing your tail.
Thanks Richard454 this is next on my list to check. So if ripple is present, can the alternator be saved by replacing the diodes? I'm assuming yes because part from them and the regulator theres not a lot else in there?
AC voltage in your system will cause the LEDs to fail.... EVERY car with an alternator will have some AC in the system that gets through unfiltered. More than .5 volts will crate havoc on electronics. LEDs and electronics like nice clean DC...Have you checked for AC ripple? Really easy to do- and will keep you from chasing your tail.
Okay, so I metered the system tonight, dc Voltage at the battery or the alternator with the engine idling is 15.2V. Testing using the meters ac scale at the battery gives 33.2 Volts. so it looks like I have problem here?
I would say so. DC battery should be 13.8 - 14-2 max running and 12.2-12-6 when not running. What kind of meter do you have. 33 ac volts seems high but I would have to check a good one. Bridge diode in regulator should filter better than that so probably open diode, I would change alternator or take it in and have repaired. Could be stator as well
Electrical oddities, need suggestions from gurus.
