Fuse box grounding out, HELP!

[hondaaccorddrew]

So, I am getting ready to install a new alternator. The plugs arent even attached yet. My choke heater was shorted, getting a new one. No big deal. Thought I would trace the white alternator wire to the fuse box for shorts. Low and behold, it is shorting. Not enough to make the meter beep, but to make it read 400 ohms or less. Almost enough to make it beep. The fun begins!:confused: so I started unplugging thins. Removed the alternator wire from the fuse box and it goes away, leading the short into the fuse box. I unplug the battery wire, it doesn't go away. I start pulling fuses and eventually the 70 amp battery fuse makes it go away. :sigh: so I start removing plugs from under the fuse box. The two largest plugs on each side of under the fuse box are causing the ground trace into the fuse box. They both cause the short to pop back up. Even if only either one is plugged in. So they are connected somehow. Where do they lead? I don't wanna burn another alternator! Sorry for the long post. Just providing as much info as possible.

[POS carb]

Probably the charge warning lamp
400 ohms is not really a short

[POS carb]

if you mean white wire as in the main charge wire, that feeds the ENTIRE electrical system of the vehicle. that 400 ohms could be the clock and radio memory.
How many amps of draw is it?
At 400 ohms 12v is only equal to a 30 milliamp draw. Your phone charger will use more than that.

[hondaaccorddrew]

if you mean white wire as in the main charge wire, that feeds the ENTIRE electrical system of the vehicle. that 400 ohms could be the clock and radio memory.
How many amps of draw is it?
At 400 ohms 12v is only equal to a 30 milliamp draw. Your phone charger will use more than that.

This meter cannot measure current unfortunately, the ones that could were way over my budget when I bought this unit. I was doing this check without an alternator and battery in the car also. I found the wire that was reading the short to ground and it was a thick blue wire that has a black stripe. Instead of reading 400 ohms, it went straight to beeping on continuity test. This wire goes many places including the fan under the dash and into the spaghetti under the steering wheel. I kept unplugging the plugs that had this wire but it never did stop beeping. Are there any wires that are supposed to go to ground in this box? I would thjnk it's positive only... I just don't wanna blow another alternator or worse. If I shouldn't worry, I won't.

[Dr_Snooz]

I'm completely confused by this thread. What happened to the last alternator? What are your symptoms that you are going to all this troubleshooting effort?

[hondaaccorddrew]

I'm completely confused by this thread. What happened to the last alternator? What are your symptoms that you are going to all this troubleshooting effort?

I am sorry, my bad for not describing the alternator situation. I have gone through 3 alternators since I got this car in March of 2009. First one randomly went out one day while warming up in June of 09. Second one went out right after the two year warrany expired in July of 11. It wouldn't power the choke heater and it would give me a battery light, even though it charged. It lasted me until two weeks ago when I installed a replacement myself. Lifetime warranty on this one. Ran for a half hour and started on fire on the inside. Failed all tests and got a new one. Determined that the choke heater was grounding out and that it was trashing the alternators. Before hooking up the replacement, I decided to check for more shorts just in case, and that's where this post comes in. I hope this sheds more light onto the subject...

[hondaaccorddrew]

if you mean white wire as in the main charge wire, that feeds the ENTIRE electrical system of the vehicle. that 400 ohms could be the clock and radio memory.
How many amps of draw is it?
At 400 ohms 12v is only equal to a 30 milliamp draw. Your phone charger will use more than that.

If I may clarify, I am not doing a current draw test. I was doing the test without the alternator and battery in place. I was doing a continuity test on my mulit-meter and I was touching everything that was positive to ground to find shorts. Which led me to the thick blue wire with a black stripe that is plugged in under the fuse box. When connected to the fuse box, it has 400 ohms resistance. When I run the blue wire to ground during a test, the meter beeps and has little resistance. I am trying to find out what all is connected to this wire. It leads into the fan under the dash but the beeping doesn't stop when it's unplugged. Is this wire suppose to be grounding? It wouldn't make sense to have a ground in a positive voltage fuse.

[Dr_Snooz]

I would guess that you were buying cheap Autozone/O'Reilly/Pep Boys alternators. They like to fail for any old reason, especially when a big tow bill will be involved. Lifetime warranty alternators are the worst of all. If you are not experiencing any other wiring issues (smelling burnt wires, blowing bulbs and fuses, random lights turning on and off or any other assorted gremlins) then I would stop digging into the wiring and buy a good alternator first. Napa is a good start, but I've been getting a lot of garbage from them lately. If it were me, I'd buy a Denso or Beck/Arnley rebuilt from RockAuto.com. Failing that, O'Reilly sells a Beck/Arnley rebuilt, but it's a special order (at least at my local store it is). Don't take the cheap one they quote you over the phone. It will be the same as what you have been getting. You can also call around to local alternator shops to see if you can get parts for the one you have. Rebuild it yourself, if you're up to it, and you'll know it was done right.

If you continue blowing good alternators, then we can dig deeper.

[POS carb]

The heavy BLU/BLK feeds the fan relay and then both fans on the carbed cars.
Step 1 is unplug engine fuse #9. Check which pin has 12v, this is the "hot" pin. Check for short/continuity to ground on the other pin. If you have continuity, unplug the fan relay, check again. If you still have continuity to ground, the short is in the fuse box. If continuity disappears, swap the fan relay with the window relay and check again, you may just need a relay.

[POS carb]

if there is no continuity to ground between the fuse pin and ground at all, the problem is in the fans or the wire feeding them. just because a fan spins doesn't mean it's good. it could have a few windings cooked in it and use way too much power.

[lostforawhile]

if you had a short to ground through the alternator the alternator wire would have melted, or the 70 amp battery fuse would have blown from the battery trying to ground through it. You are reading phantom shorts from a digital meter, thats an issue with the type of meter. There are a number of circuits in the car that could fool you into thinking you have a short. This is why I like the old analog meters for working on 12 volt stuff

[hondaaccorddrew]

The heavy BLU/BLK feeds the fan relay and then both fans on the carbed cars.
Step 1 is unplug engine fuse #9. Check which pin has 12v, this is the "hot" pin. Check for short/continuity to ground on the other pin. If you have continuity, unplug the fan relay, check again. If you still have continuity to ground, the short is in the fuse box. If continuity disappears, swap the fan relay with the window relay and check again, you may just need a relay.


if there is no continuity to ground between the fuse pin and ground at all, the problem is in the fans or the wire feeding them. just because a fan spins doesn't mean it's good. it could have a few windings cooked in it and use way too much power.

Thank you so much for this info. I will look into it. Yeah both the fans work. But they draw the whole car down, is that normal? They take a lot of current when on :D do I just unplug them and test the positive wire to ground? If they fail the test, what all is required to remove them? I don't wanna tear a whole front end off, can they just slip out? It's raining here for a whole week so it could be a while before I can test.

[hondaaccorddrew]

if you had a short to ground through the alternator the alternator wire would have melted, or the 70 amp battery fuse would have blown from the battery trying to ground through it. You are reading phantom shorts from a digital meter, thats an issue with the type of meter. There are a number of circuits in the car that could fool you into thinking you have a short. This is why I like the old analog meters for working on 12 volt stuff

Lol I wasn't trained in using analog in electronics class, just the digital ones. Can you still buy them?

[hondaaccorddrew]

I would guess that you were buying cheap Autozone/O'Reilly/Pep Boys alternators. They like to fail for any old reason, especially when a big tow bill will be involved. Lifetime warranty alternators are the worst of all. If you are not experiencing any other wiring issues (smelling burnt wires, blowing bulbs and fuses, random lights turning on and off or any other assorted gremlins) then I would stop digging into the wiring and buy a good alternator first. Napa is a good start, but I've been getting a lot of garbage from them lately. If it were me, I'd buy a Denso or Beck/Arnley rebuilt from RockAuto.com. Failing that, O'Reilly sells a Beck/Arnley rebuilt, but it's a special order (at least at my local store it is). Don't take the cheap one they quote you over the phone. It will be the same as what you have been getting. You can also call around to local alternator shops to see if you can get parts for the one you have. Rebuild it yourself, if you're up to it, and you'll know it was done right.

If you continue blowing good alternators, then we can dig deeper.

Well i put in a replacement. Yeah it's an O'Reilly. I didn't buy it, so I have. I choice. When I can buy a new one though I will. New ones are hard to come by for these cars. Only store I can find that sells new ones is Napa. Anyhow, the replacement has not caused any issue so far and is charging at the correct voltage. For now...

[lostforawhile]

Lol I wasn't trained in using analog in electronics class, just the digital ones. Can you still buy them?

Yes they still make them digital meters are great,but they can cause oddball readings in. Car electrical systems,both have a place,test lamps also have a place,a digital meter will show a circuit is good even with a corroded connection that wont allow current flow

[POS carb]

Thank you so much for this info. I will look into it. Yeah both the fans work. But they draw the whole car down, is that normal? They take a lot of current when on :D do I just unplug them and test the positive wire to ground? If they fail the test, what all is required to remove them? I don't wanna tear a whole front end off, can they just slip out? It's raining here for a whole week so it could be a while before I can test.

You can test the wire to ground but I am not sure what the reading should be.
I made a ghetto amp "meter" with a headlight once.
What you do is wire it in line with the positive wire.

(+)----bulb-----fan-----(-)
Plug this into one fan's + and note the brightness
try the same on the other fan
The fan that makes the bulb burn brightest is drawing the most current
Keep in mind that they may both be bad...
The fuse is 30 amps so the combined draw of the fans should never exceed 25 amps. If current = voltage/resistance then each fan should be no less than 1 ohm......... You won't be able to measure anything with the bulb, it just helps you choose where to start.

The fans can be removed without disassembling anything else. Just unplug and unbolt them. The main fan has 4 bolts, the condenser fan has 3

[hondaaccorddrew]

Yes they still make them digital meters are great,but they can cause oddball readings in. Car electrical systems,both have a place,test lamps also have a place,a digital meter will show a circuit is good even with a corroded connection that wont allow current flow

Too bad they don't make a meter you can hook to the battery and hook something (fans, moter, etc) to test and see how much current it takes or limit it to a certain amount. Alas, I am not a rich person so such a device is out of my price range.

[hondaaccorddrew]

You can test the wire to ground but I am not sure what the reading should be.
I made a ghetto amp "meter" with a headlight once.
What you do is wire it in line with the positive wire.

(+)----bulb-----fan-----(-)
Plug this into one fan's + and note the brightness
try the same on the other fan
The fan that makes the bulb burn brightest is drawing the most current
Keep in mind that they may both be bad...
The fuse is 30 amps so the combined draw of the fans should never exceed 25 amps. If current = voltage/resistance then each fan should be no less than 1 ohm......... You won't be able to measure anything with the bulb, it just helps you choose where to start.

The fans can be removed without disassembling anything else. Just unplug and unbolt them. The main fan has 4 bolts, the condenser fan has 3

I'll give it a shot, I'll also look in the manual to see if they list something on testing with a meter. I know it says something about the fans, but not entirely sure on what. Dont have any spare bulbs laying around.

[lostforawhile]

Too bad they don't make a meter you can hook to the battery and hook something (fans, moter, etc) to test and see how much current it takes or limit it to a certain amount. Alas, I am not a rich person so such a device is out of my price range.
they do make one it's just an ammeter

[Dr_Snooz]

they do make one it's just an ammeter

And they can be had for as little and $9.99.

http://www.harborfreight.com/digital-clamp-on-multimeter-95652.html

[hondaaccorddrew]

they do make one it's just an ammeter

Lol, I was being sarcastic on that. Last time I looked they were so much money, but Dr_Snooz has found a great one from Harbor Freight. SO I think I will get it. P.S. The replacement Choke Coil has arrived, any tips on replacement? I have a cold start issue also, so I know I will be adjusting the choke tabs. Any tips on correct adjustment? Unfortunately the manuals' ways of adjustment is too complicated sounding. And needs special tools. Gah!

[hondaaccorddrew]

And they can be had for as little and $9.99.

http://www.harborfreight.com/digital-clamp-on-multimeter-95652.html

Thank you so much! I will go purchase this device! I have been looking for some, the ones that could do it at the parts and home supply stores were over $50!

[hondaaccorddrew]

And they can be had for as little and $9.99.

http://www.harborfreight.com/digital-clamp-on-multimeter-95652.html

Sadly, this one only measures current in AC, and those found in Harbor Freight's site are only capable of measuing up to 20 amps DC. Ones valuable for car use (up to 600 amps DC) are upwards of $70.

[lostforawhile]

Sadly, this one only measures current in AC, and those found in Harbor Freight's site are only capable of measuing up to 20 amps DC. Ones valuable for car use (up to 600 amps DC) are upwards of $70.

most of what you need to measure in a car is going to be 20 amps or less anyway,anything bigger you need one of the big ones for measuring starter draw etc

[Oldblueaccord]

Remember also you are always checking continuity with the power OFF and on a car the battery unhooked.

With continuity the meter is sending voltage out to check SO even if you have a say10 gauge wire only one strand needs to be making contact for it to test continuity but it wont be able to carry much current.

wp

[hondaaccorddrew]

Remember also you are always checking continuity with the power OFF and on a car the battery unhooked.

With continuity the meter is sending voltage out to check SO even if you have a say10 gauge wire only one strand needs to be making contact for it to test continuity but it wont be able to carry much current.

wp

Yeah, I did all my testing with the battery off and I hadn't even installed my alternator yet. I was tracing with no power to the car. And it does make sense on the one strand making contact part. Learned the hard way on something like that :D

[hondaaccorddrew]

most of what you need to measure in a car is going to be 20 amps or less anyway,anything bigger you need one of the big ones for measuring starter draw etc

I have an amplifier for my speakers in here though. Takes up to 80 amps on full load, have never turned it up that high however.

[lostforawhile]

I have an amplifier for my speakers in here though. Takes up to 80 amps on full load, have never turned it up that high however.

there isn't much point in trying to measure current for an amp as it changes all the time, it might not be a good idea to run an amp that pulls more current them the alternator anyway,

[hondaaccorddrew]

there isn't much point in trying to measure current for an amp as it changes all the time, it might not be a good idea to run an amp that pulls more current them the alternator anyway,

So a good idea is to remove the amp or get a high powered alternator?

[lostforawhile]

So a good idea is to remove the amp or get a high powered alternator?
if you search the site, I'm not exactly sure where, there is a how to in installing the legend alternator, it's a higher output alternator, you will need to run a heavier gauge alternator output wire though, I would just run it to the starter lug. If you are really pulling a lot of current all the time and draining the battery down, your alternator is going to suffer. The entire electrical system runs on the alternator when the car is running, if you pull more current then the alternator can produce or close to it's output, it's going to run hot and put a lot of strain on it. If you drain the battery way down and then the alternator has to charge it back up, it's going to possibly damage the alternator, the alternator is designed to run the electrical system and top the battery back up after starting. it's not designed to charge a mostly drained battery back up or run near it's rated output all the time. This is why you should always charge your battery back up with an external charger after a jump start

[hondaaccorddrew]

if you search the site, I'm not exactly sure where, there is a how to in installing the legend alternator, it's a higher output alternator, you will need to run a heavier gauge alternator output wire though, I would just run it to the starter lug. If you are really pulling a lot of current all the time and draining the battery down, your alternator is going to suffer. The entire electrical system runs on the alternator when the car is running, if you pull more current then the alternator can produce or close to it's output, it's going to run hot and put a lot of strain on it. If you drain the battery way down and then the alternator has to charge it back up, it's going to possibly damage the alternator, the alternator is designed to run the electrical system and top the battery back up after starting. it's not designed to charge a mostly drained battery back up or run near it's rated output all the time. This is why you should always charge your battery back up with an external charger after a jump start

Sounds like a plan! Thanks :D