Bad Alternator Maybe

[Ricker]

It started when the original passenger door lock would not only lock every time, just sometimes. So, I got a new controller and solenoids for both doors. Same thing happened, no change. I also noticed that when the battery was on the trickle charger and fully charged, the passenger door lock would work (the issue is only the unlocking of the passenger door). However, when the dashboard voltmeter gauge started to drop (and this happens in 10 minutes of driving or so), the door lock quit working. The passenger solenoid seemed not to get enough power/amps. I had the battery tested at the auto parts store. It checked out. It also would take a full charge from the battery trickle charger. I don't think it is the battery. It is 36 months old. It reads with the car off 12.99 VDC. With the car running 14.47 VDC. When the car has the A/C and lights on 13.85 VDC. Voltage seems fine but what about the amps?

With an amp meter clamped around the positive (red) cable connected directly to the battery with low engine RPMs it jumps around but averages 2 AMPS DC. With high RPMs it averages 1 AMP DC. Turning on the A/C and lights and low RPMs, it is still averaging 2 AMPS DC. With high RPMs and A/C and lights 2 AMPS DC.

From when the battery is fully charged and the dashboard voltage gauge reading is as high as it gets, it always continually drops and never gets back up the same reading until the battery is on the trickle charger again. Not had a problem with the car running out of alternator power yet.

Does any of this indicate an alternator going bad or is there something else going on? It is a 130 AMP aftermarket alternator.

[Bitsyncmaster]

When the battery is fully charged, it will not show much charging current. My battery will drop to less then 0.10 amps after it is on a charger set to 14.50 volts for a few days.

When you add loads the car voltage drops so you may get a little more charge current into the battery. If you want to test it, put your headlights on for about 15 or 20 minuets with the engine not running. That should drain some charge and you should see over 10 amps of charging when you run the engine.

[Ricker]

When the battery is fully charged, it will not show much charging current. My battery will drop to less then 0.10 amps after it is on a charger set to 14.50 volts for a few days.

When you add loads the car voltage drops so you may get a little more charge current into the battery. If you want to test it, put your headlights on for about 15 or 20 minuets with the engine not running. That should drain some charge and you should see over 10 amps of charging when you run the engine.

I ran the low and high beam halogen lights for 20 minutes with the car off. Started the car with the amp meter on the battery positive wire. Got a reading jumping between 4 and 2 amps. Gunned the engine, no change.

[Bitsyncmaster]

I ran the low and high beam halogen lights for 20 minutes with the car off. Started the car with the amp meter on the battery positive wire. Got a reading jumping between 4 and 2 amps. Gunned the engine, no change.

Sounds like you have a problem but if your voltage with engine running is 14.5 volts then the alternator is working. Is your current meter set to read DC current? Sounds like it is reading AC current.

[Ricker]

Sounds like you have a problem but if your voltage with engine running is 14.5 volts then the alternator is working. Is your current meter set to read DC current? Sounds like it is reading AC current.

Yes, I'm sure it was on DC Amps. Can the alternator have the correct voltage but not produce the amps? Does the fact the amp reading jumping around mean anything? Should I run down the battery some more and get another reading?

[Bitsyncmaster]

Yes, I'm sure it was on DC Amps. Can the alternator have the correct voltage but not produce the amps? Does the fact the amp reading jumping around mean anything? Should I run down the battery some more and get another reading?

If your reading 14.5 volts on the battery with engine running then your alternator is good as are the connections. Try reading current again making sure your meter is on DC amps. You can test your meter clamping it over another load wire like headlights or cooling fans. The alternator puts out a 3 phase rectified AC current.

[Patrick C]

It started when the original passenger door lock would not only lock every time, just sometimes. So, I got a new controller and solenoids for both doors. Same thing happened, no change. I also noticed that when the battery was on the trickle charger and fully charged, the passenger door lock would work (the issue is only the unlocking of the passenger door). However, when the dashboard voltmeter gauge started to drop (and this happens in 10 minutes of driving or so), the door lock quit working. The passenger solenoid seemed not to get enough power/amps. I had the battery tested at the auto parts store. It checked out. It also would take a full charge from the battery trickle charger. I don't think it is the battery. It is 36 months old. It reads with the car off 12.99 VDC. With the car running 14.47 VDC. When the car has the A/C and lights on 13.85 VDC. Voltage seems fine but what about the amps?

When is the last time you went around the car and cleaned all of the ground points? I think that would be worth a shot.

[Timeless]

When is the last time you went around the car and cleaned all of the ground points? I think that would be worth a shot.
Great advice. I cleaned/improved grounds on my car that sat 20 years and it has rock sold voltage all the time. Hot, cold, all lights/stereo on, A/C blasting in S.FL summers.

[Ricker]

I went out just now and turned the high and low beams on for another 20 minutes. With the lights on and engine not running battery voltage was 11.85 VDC. Lights on and engine running voltage was 14.1 VDC. Lights on and engine running battery reading was jumping around but all over 20 AMPS DC. All seems fine.

I have cleaned the ground inside on the fire wall. Not sure where the others are, specifically for the door locks.

The passenger door will lock only 3 times then that is it. I even by-passed the thermal and nothing changed. Unlock every time. No idea where to check from here.

[Bitsyncmaster]

I went out just now and turned the high and low beams on for another 20 minutes. With the lights on and engine not running battery voltage was 11.85 VDC. Lights on and engine running voltage was 14.1 VDC. Lights on and engine running battery reading was jumping around but all over 20 AMPS DC. All seems fine.

I have cleaned the ground inside on the fire wall. Not sure where the others are, specifically for the door locks.

The passenger door will lock only 3 times then that is it. I even by-passed the thermal and nothing changed. Unlock every time. No idea where to check from here.

Door locks take quite a bit of getting them correct. Both door switches need to be solid working together. The problem is they are wired in parallel. If they were separate inputs the ECU could accept some miss alignment.

[Ricker]

Door locks take quite a bit of getting them correct. Both door switches need to be solid working together. The problem is they are wired in parallel. If they were separate inputs the ECU could accept some miss alignment.

What gets me is that after each time when only the passenger door lock quits working it doesn't just not work. Each time the solenoid just doesn't go the full distance less and less as though there is not enough power/amps. I tried by bypassing the thermal trip. No change. Is there a different source easily for the 12 VDC I can try to see if the power is the issue? I don't believe this is the issue. But I'm at a loss because I have adjusted the solenoid for days.

The other thing is for the 12 years I have owned the car the locks were never an issue. Never touched anything to do with them. Then slowly this started happening.

After fighting this for months, I may just disconnect the power and do everything manually. Grrrr.

[Bitsyncmaster]

What gets me is that after each time when only the passenger door lock quits working it doesn't just not work. Each time the solenoid just doesn't go the full distance less and less as though there is not enough power/amps. I tried by bypassing the thermal trip. No change. Is there a different source easily for the 12 VDC I can try to see if the power is the issue? I don't believe this is the issue. But I'm at a loss because I have adjusted the solenoid for days.

The other thing is for the 12 years I have owned the car the locks were never an issue. Never touched anything to do with them. Then slowly this started happening.

After fighting this for months, I may just disconnect the power and do everything manually. Grrrr.

Does it work when the engine is running. That would give you an idea if it needs more power or that door has some binding with the latches. Are you running OEM solenoids or actuators? The solenoids use about 25 amps when both operate. So a bad connection would be more of a problem with solenoids. The actuators take less then 10 amps for both.

[Ricker]

Does it work when the engine is running. That would give you an idea if it needs more power or that door has some binding with the latches. Are you running OEM solenoids or actuators? The solenoids use about 25 amps when both operate. So a bad connection would be more of a problem with solenoids. The actuators take less then 10 amps for both.

Doesn't seem to matter if the engine is running or not. Also, whether the engine is at idle or high RPM.

I have the DeloreanGo controller and solenoids. The solenoids are the 2-wire type as opposed to the 3-wire originals. I guess I could try the actuators (from DMC Industries I guess) but not sure the DeloreanGo controller would work with them. I choose DeloreanGo because DMC Industries did not have the controller in stock.

[Bitsyncmaster]

Doesn't seem to matter if the engine is running or not. Also, whether the engine is at idle or high RPM.

I have the DeloreanGo controller and solenoids. The solenoids are the 2-wire type as opposed to the 3-wire originals. I guess I could try the actuators (from DMC Industries I guess) but not sure the DeloreanGo controller would work with them. I choose DeloreanGo because DMC Industries did not have the controller in stock.

All the actuators I've seen are two wire. The ECU reverses the polarity to lock or unlock. I've not tested the Dgo ECU for timing. I've set my timing on my ECU to 150 ms. The OEM ECU was about 100 ms but the solenoids are faster. I have Toby's actuators in my car.

[Ricker]

All the actuators I've seen are two wire. The ECU reverses the polarity to lock or unlock. I've not tested the Dgo ECU for timing. I've set my timing on my ECU to 150 ms. The OEM ECU was about 100 ms but the solenoids are faster. I have Toby's actuators in my car.

When I ran the battery down the second time I measured the amps from the alternator to the battery. It was 20 amps or slightly above. I tried the passenger door lock. This popped the 20 AMP fuse as part of the DoGo input to the controller. So, this means the solenoid was drawing plus 20 amps. What does that mean? This is so crazy.

[Bitsyncmaster]

When I ran the battery down the second time I measured the amps from the alternator to the battery. It was 20 amps or slightly above. I tried the passenger door lock. This popped the 20 AMP fuse as part of the DoGo input to the controller. So, this means the solenoid was drawing plus 20 amps. What does that mean? This is so crazy.

Maybe you do have a bad solenoid or a shorted wire somewhere.

[Ricker]

Maybe you do have a bad solenoid or a shorted wire somewhere.

I think I am going to get the actuators and get rid of the new solenoids. Not sure if I continue to use the DeloreanGo Controller, get a different one, or (not sure this is even possible) use the original look controller. I'll be getting in contact with DMC Northwest and see.

[Bitsyncmaster]

I think I am going to get the actuators and get rid of the new solenoids. Not sure if I continue to use the DeloreanGo Controller, get a different one, or (not sure this is even possible) use the original look controller. I'll be getting in contact with DMC Northwest and see.

Original lock ECU will not work with actuators unless you install a bank of relays. But even then the timing is a little short for actuators.

[Ricker]

Original lock ECU will not work with actuators unless you install a bank of relays. But even then the timing is a little short for actuators.

I did get the actuators from Delorean Northwest to operate with the original door lock controller. They did come with two relays. Everything is operating as it should so far. Time will tell.