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Discussion Starter · #221 · (Edited)
Before I do anymore tests I am going to do something I have never done. I am going to take off the alternator heat shield and shove a ground in the full field hole. If the alternator suddenly works, then yes, the regulator is fucked which will be un-fuckin-believable given I have replaced the alternator twice. I will shoot someone.
 

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Discussion Starter · #222 · (Edited)
I am now absolutely positive I know what is going on. A component within the ignition circuit is not grounding and its finding ground through the alternator or coolant temperature gauge sender, both of which are in the ignition circuit but ground to the engine and not G401, G402 and G471. That's why one or the other works at a given time and why I found massive voltage leaking in a voltage drop test in the alternator ignition circuit in post #185 despite correct voltage. I dont understand enough about how its affecting the regulator but I do know that the coolant temperature gauge sender works by resistance and is very sensitive. So I now need to start pulling fuses and or disconnecting individual components within the ignition circuit to find the culprit.

Yeeeah who's awesome!
 

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Discussion Starter · #223 · (Edited)
Pulled every dash fuse except fuse 12, it made no difference.

Going back to post #185. I got a voltage drop of 0.4 volts at the ignition circuit on the alternator plug where the voltage was 12.23 volts, and yet the battery was only putting out 12.32 volts.

12.23 volts + 0.4 volts is 12.63 volts which is higher than the battery. How can that be?

The voltage at my under-hood relay box:

WHT/GRN (alternator sense): 12.32 volts
BLK/YEL (alternator ignition): 12.23 volts
BLK/WHT (Starter): 1.04 volts
YEL/RED (engine oil pressure switch): 12.20 volts
WHT/BLK: 11.67 volts
WHT/RED: 10.27 volts
WHT/BLU (charging system warning light): 12.23 volts
RED (coolant temperature gauge sender): 10.53 volts


Why is the starter circuit showing 1.04 volts? Isn't that circuit suppose to only be enegised when the key is on start? Its like something within the ignition circuit has a bad ground and is bleeding out to other components within the circuit. This would explain the gauge going up, but I don't know about the alternator regulator. This theory is kind of out the window though as I pulled the gauge fuse and the problem persisted.

Perhaps there is higher current in the ignition circuit going to the regulator and its computer is overclocking and crashing.

Is there any smart people around or just new age sensitive males who are easily offended over the internet?
 

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Try checking the grounds by checking if there is a voltage flowing in the ground circuit.
If you check from the negative terminal of the battery (with the battery still connected normally) to various grounded metal surfaces you want to check, (engine, frame/chassis etc.) there should almost 0v flowing, there may be a few millivolts in older vehicles, but if its higher than that, you have found the poor ground.
 

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Discussion Starter · #225 · (Edited)
Cleaning G401 and G402 didn't help. The alternator dropped in and out of charging and then eventually just stopped charging.

I now know what the problem is. I have a short to power. That's why I am getting a voltage drop of 0.4 volts on the ignition wire at the alternator plug despite the voltage being good, and why I am also getting voltage in places I shouldn't, such as 1.04 volts on the starter wire in the engine wire harness.

Voltage drop test:

BLK/YEL (IG) at alternator plug (unplugged) to battery positive post: 400
WHT/BLU (L) at alternator plug (unplugged) to battery positive post: 363
WHT/GRN (S) at alternator plug (unplugged) to battery positive post: 037
Alternator B post to battery positive post: 038


Voltage test at under-hood relay box plug:

WHT/GRN (alternator sense): 12.32 volts
BLK/YEL (alternator ignition): 12.23 volts
WHT/BLU (alternator warning light): 12.23 volts
YEL/RED (engine oil pressure switch): 12.20 volts

BLK/WHT (starter motor): 1.04 volts
WHT/RED ((unknown)): 10.27 volts
RED (coolant temperature gauge sender): 10.53 volts
WHT/BLK (ALB control unit): 11.67 volts


The alternator and temperature gauge run through separate circuits after the dash fuse box which rules the fault being past the dash fuse box, and the starter motor BLK/WHT wire is independent from the ignition switch BAT-A IG-1 as it runs through BAT-A ST, and I believe the start motor wire is only suppose to be energised when the key is turned to start, so this suggests to me that there is a short to power from the wires beyond the ignition switch to, and including the dash fuse box.

What do others reckon?

I have no idea how to tackle a short to power so if anyone knows, please help!

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Try checking the grounds by checking if there is a voltage flowing in the ground circuit.
If you check from the negative terminal of the battery (with the battery still connected normally) to various grounded metal surfaces you want to check, (engine, frame/chassis etc.) there should almost 0v flowing, there may be a few millivolts in older vehicles, but if its higher than that, you have found the poor ground.
Oops I forgot the most important thing, there needs to be current flow the higher the better, for body ground turn on headlights fan motor etc. For engine ground testing crank engine while checking for voltage between battery negative and engine block. Should be almost 0v in both cases.
 

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Discussion Starter · #227 ·
I found the problem. It ended up being the ignition switch. One of the little springs on the inside has lost its resistance and isn't pushing the inner piece into the ignition contact properly and is off shooting, shorting the ignition circuit with the starter motor circuit. When I push the key into the cylinder, the charging system problem goes away.

I win


This is a throw away account I never really cared about so this is my last post. For once I will make a post I'm not going to edit! lol

Thanks everyone who gave me their time.
 

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Discussion Starter · #228 ·
I am back. The problem wasn't the ignition switch. It WAS the fucking regulator. Faulcun was right. He told me he had a string on 7 alternators bad in a row. I didn't believe him.

I got my 'new' (remanufactured) alternator, it didn't work. I got a replacement alternator sent out, that didn't work either. I thought no way two alternators bad in a row, the problem must be elsewhere, so never full field tested the second replacement alternator. Well I did a full field test on my alternator tonight and what do you fucking know?! The regulator is bad!

These fuckin dumb cunts in Mexico who remanufacture these alternators are using fucking Chinese regulators which are absolute junk. It seems their 'bench testing' results are either fake or their bench testing is just spinning up the alternators with a drill and full field testing them, bypassing the regulator instead of actually creating the ignition and sense circuits and testing if the regulator works.

Here is a video of the full field test I did: https://filebin.net/5agad223i1dyfeu2/Trash_regulator.mp4
 

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Discussion Starter · #230 ·
No, Faulcun was right. You said it was a charge harness problem and told me to jump the alternator B post to the battery, and you only said that after you saw me say on the HONDA PRELUDE Facebook group that it looks like a wiring issue. You rushed over here to post one minute after to try and look smart. You think I didn't notice?! LOL

https://www.preludepower.com/thread...ix-this-problem.463963/page-7#post-1986665209
 

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No, Faulcun was right. You said it was a charge harness problem and told me to jump the alternator B post to the battery, and you only said that after you saw me say on the HONDA PRELUDE Facebook group that it looks like a wiring issue. You rushed over here to post it in just 1 minute to try and look smart. You think I didn't notice?! LOL

https://www.preludepower.com/thread...ix-this-problem.463963/page-7#post-1986665209
I told you to test the charge harness but you refused to even try.
And you did not even try to get another replacement alternator when it was said that it could be bad part.

You were being too stubborn in your testing because it was too hard, so now we are back to what could have been resolved with one thread.
 

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Discussion Starter · #232 · (Edited)
I did test the harness. I pulled the entire engine wire harness out of the car, stripped it down, cleaned it, put it back together and then back in the car. I still have the cuts on my hands from that ordeal. Previously I also chopped off the alternator plug and attached a new one. I've tried everything except jumping B to the battery, as that made no sense as the regulator was not functioning.

I am on my second replacement alternator, I didn't think two alternators could be bad in a row. I forgot how dumb used car people are.

I had mental health issues when this problem started, that's why the road has been a disaster and I walked away from the car and let it sit for a year while I worked on getting my life back together.
 

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I did test the harness. I pulled the entire engine wire harness out of the car, stripped it down, cleaned it, put it back together and then back in the car. I still have the cuts on my hands from that ordeal. Previously I also chopped off the alternator plug and attached a new one. I've tried everything except jumping B to the battery, as that made no sense as the regulator was not functioning.
Well from now on, just keep it simple when triaging these cars.
They are not complicated.
 

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No, Faulcun was right. You said it was a charge harness problem and told me to jump the alternator B post to the battery, and you rushed to post it after you saw me already stating the problem looked like a wiring on the HONDA PRELUDE Facebook group.

https://www.preludepower.com/thread...ix-this-problem.463963/page-7#post-1986665209

LOL
I also said the biggest problem with diagnosing over the internet is relying on one persons information that nobody can verify is done correctly. 90% of the time, going in circles is the result of a improper diagnosis.

Everybody was going down this path with you because we were relying on the information given. What he was suggesting was correct in diagnosis. IF there was a question about a bad wire, you can substitute the wires one by one and see if your problems go away. It was just the next step down a path after it was insisted that the alternator wasnt bad.

And I get it. I do. Ive been in your shoes on multiple vehicles, questioned myself as a qualified, capable technician with 20 years of professional automotive experience, ASE certified master technician, and a honda specialist.... all because of an alternator on a chevy mailbu. At the end of the day, its just another learning experience. I appreciate the shout-out, but i hope this has been a humbling experience for you.
 

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Discussion Starter · #236 · (Edited)
I am still using the same second replacement alternator. The hardware is actually brand spanking new, apart from the case which looks acid washed as it too looks brand new.


Well I bought a new aftermarket regulator off eBay. Its different than the aftermarket piece of shit that came in my replacement alternators. It has completely fixed the problem!

This is the piece of shit that I put my faith in. Look at how its been stuck together with white silicon. That manufacturing technique is China 2005! I have pulled it apart but there was also two red spray painted metal wires coming out of the back part which went back inside the compartment. They connected from the two solder points at the bottom of the PCB. What the fuck?! And their is some sticky shit all over the circuit board, dialectic grease? But its sealed, why the fuck would you do that?!

These people are clueless, seriously. Peasant mentality manufacturing. Mao would have been proud.

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Discussion Starter · #237 ·
I am still in the Prelude club! Fuck! I survived! And it felt so good driving this low-to-the-road car around all these modern day plastic pieces of crap and hipsters in their hatchbacks thinking their cool telling Siri to change the song. I'm gonna look after this car so well now. Tomorrow I am changing the valve cover gasket and I ordered the distributor internal oil seal.
 

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Discussion Starter · #238 ·
This is a trick I do when I get lazy and CBF disconnecting the battery. I put a balloon over the B wire and wrapped a rubber band around it, but its also a legitimate trick for sealing coolant and fuel hoses to stop fluid going everywhere. People might wanna copy.

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Discussion Starter · #240 · (Edited)
Who wants to hear a funny story? That new 'high quality parts from China' regulator I bought off eBay is failing. The battery charge light won't come on during cluster test but then it flares constantly while driving, even though the alternator is charging.

These people are pathetic, seriously.

I'm going to buy a second hand OEM regulator.
 
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