Will it never end?
#1
![Default](/forum/images/icons/icon1.gif)
As soon as I got my fuel pump check valve fixed another problem showed up. Now my battery drains overnight. When I try to start it the next day either it barely cranks, or I just get a click. I took it to the parts store today to have them load test the battery, and it's fine. In fact, it was supposed to have 850 cold cranking amps but it tested out at 897.
So now I need to track down whatever is draining my battery. I'm going to use the ammeter/fuse pulling method. This might take a while.
So now I need to track down whatever is draining my battery. I'm going to use the ammeter/fuse pulling method. This might take a while.
#2
![Default](/forum/images/icons/icon1.gif)
As soon as I got my fuel pump check valve fixed another problem showed up. Now my battery drains overnight. When I try to start it the next day either it barely cranks, or I just get a click. I took it to the parts store today to have them load test the battery, and it's fine. In fact, it was supposed to have 850 cold cranking amps but it tested out at 897.
So now I need to track down whatever is draining my battery. I'm going to use the ammeter/fuse pulling method. This might take a while.
So now I need to track down whatever is draining my battery. I'm going to use the ammeter/fuse pulling method. This might take a while.
![Icon Doh](https://www.jaguarforums.com/forum/images/smilies/icon_doh.gif)
Last edited by Paul Pavlik; 11-16-2011 at 05:52 PM.
#3
![Default](/forum/images/icons/icon1.gif)
What other things did you do to the car other than pulling the tank? If I recall you had a problem pulling that tank out, do you think a wire could have been pinched? I found this tool to be useful 30 Amp Automotive Fuse Circuit Tester I hope it helps!
Also in 20A http://www.harborfreight.com/catalog...Circuit+Tester
Also in 20A http://www.harborfreight.com/catalog...Circuit+Tester
Last edited by Gus; 11-16-2011 at 06:23 PM. Reason: Add 20A tester
The following users liked this post:
WhiteXKR (11-23-2011)
#5
Join Date: Nov 2006
Location: Glasgow, Scotland UK
Posts: 47,302
Received 9,011 Likes
on
4,114 Posts
#6
![Default](/forum/images/icons/icon1.gif)
Howdy Rev:
I could not tell if you were going to check every fuse or not.
What I did was to disconnect the 12v cable from one fuse block(EDIT:take care as to not let this live cable touch any metal since welding / arching could occur) , and then check the total battery drain current at full sleep. If the total battery drain read more than ~35ma I would reconnect the cable and go to the next fuse block and check it in similar fashion. Otherwise reconnect that block and pull each fuse one at a time, checking total sleep current, then replace that fuse before going to the next one till the culprit circuit is found. (I saved the passenger fascia (LHD) block for last since I could not easily diconnect that 12v cable and did have to go one fuse at a time.)
My drain turned out to be fuse #15 on pass fascia box. As of lately, it seems to have fixed itself on its own. I used a cheap digital multimeter set on the 10 amp scale.(lower scales required care as to not wake up the sleep mode which in turn would blow the 300ma fuse in my tester)
Since we are looking for a target current ~25ma, I am not seeing the Harbor Freight fuse tester to be benefical if it has a resolution of 100ma.
If your findings do appear to be a module circuit, I have since read, (but have not checked mine yet) to compare the B+ voltage at the module to the voltage at the battery terminals as a small voltage drop could prevent the module from going into full sleep mode.
I could not tell if you were going to check every fuse or not.
What I did was to disconnect the 12v cable from one fuse block(EDIT:take care as to not let this live cable touch any metal since welding / arching could occur) , and then check the total battery drain current at full sleep. If the total battery drain read more than ~35ma I would reconnect the cable and go to the next fuse block and check it in similar fashion. Otherwise reconnect that block and pull each fuse one at a time, checking total sleep current, then replace that fuse before going to the next one till the culprit circuit is found. (I saved the passenger fascia (LHD) block for last since I could not easily diconnect that 12v cable and did have to go one fuse at a time.)
My drain turned out to be fuse #15 on pass fascia box. As of lately, it seems to have fixed itself on its own. I used a cheap digital multimeter set on the 10 amp scale.(lower scales required care as to not wake up the sleep mode which in turn would blow the 300ma fuse in my tester)
Since we are looking for a target current ~25ma, I am not seeing the Harbor Freight fuse tester to be benefical if it has a resolution of 100ma.
If your findings do appear to be a module circuit, I have since read, (but have not checked mine yet) to compare the B+ voltage at the module to the voltage at the battery terminals as a small voltage drop could prevent the module from going into full sleep mode.
Last edited by Dr. D; 11-17-2011 at 07:05 PM. Reason: Safety concerns
#7
Trending Topics
#9
#10
#12
![Default](/forum/images/icons/icon1.gif)
Sam,
Not much I can think of beyond what's been suggested.
Maybe, given the coincidence part, it would be a good first test to pull whatever fuse feeds the fuel pump and see if that makes any difference over night. [edit: On second thought, not very likely.]
Otherwise, when you've gotten a measurement of the current drain, it may(?) help us narrow down the search by ruling some things in or out.
Not much I can think of beyond what's been suggested.
Maybe, given the coincidence part, it would be a good first test to pull whatever fuse feeds the fuel pump and see if that makes any difference over night. [edit: On second thought, not very likely.]
Otherwise, when you've gotten a measurement of the current drain, it may(?) help us narrow down the search by ruling some things in or out.
Last edited by Dennis07; 11-17-2011 at 06:46 AM.
#13
![Default](/forum/images/icons/icon1.gif)
Tables hold data. Each table has an index to show the precise location of each record.
The index is like a Dewey card catalog in a library.
In a Dewey, the cards are divided into drawers: A-C, D-F, etc. An index has a "master drawer" with A-J on the left side, and K-Z on the right.
These master cards point to a second index drawer. If looking for "Charles", the second drawer would contain cards for C on the left and D on the right.
So, by looking in the first drawer, the database eliminates all of the drawers but one, making the search much faster.
Similar?
Last edited by mcbeefsteak; 11-17-2011 at 10:18 AM.
#14
![Default](/forum/images/icons/icon1.gif)
Plums - this sounds interesting, like something I do at work. Can you elaborate?
In a database, each data set usually has an index. It works like a Dewey card catalog in a library.
In a Dewey, the cards are divided into drawers: A-C, D-F, etc.
In an index, the first drawer has A-J on the left side, and K-Z on the right. The cards all point another drawer in the index.
If you are looking for "Charles", it would point to a drawer which might contain cards for C-D. The card to find the actual data is in this second drawer.
So, by looking in the first drawer, the database immediately eliminates half the data, making the search much faster.
This is equivalent to a library patron looking at the Dewey drawers and eliminating all the wrong ones.
Similar?
In a database, each data set usually has an index. It works like a Dewey card catalog in a library.
In a Dewey, the cards are divided into drawers: A-C, D-F, etc.
In an index, the first drawer has A-J on the left side, and K-Z on the right. The cards all point another drawer in the index.
If you are looking for "Charles", it would point to a drawer which might contain cards for C-D. The card to find the actual data is in this second drawer.
So, by looking in the first drawer, the database immediately eliminates half the data, making the search much faster.
This is equivalent to a library patron looking at the Dewey drawers and eliminating all the wrong ones.
Similar?
B
#16
![Default](/forum/images/icons/icon1.gif)
Plums - this sounds interesting, can you elaborate? In databases, binary search works like this:
Tables hold data. Each table has an index to show the precise location of each record.
The index is like a Dewey card catalog in a library.
In a Dewey, the cards are divided into drawers: A-C, D-F, etc. An index has a "master drawer" with A-J on the left side, and K-Z on the right.
These master cards point to a second index drawer. If looking for "Charles", the second drawer would contain cards for C on the left and D on the right.
So, by looking in the first drawer, the database eliminates all of the drawers but one, making the search much faster.
Similar?
Tables hold data. Each table has an index to show the precise location of each record.
The index is like a Dewey card catalog in a library.
In a Dewey, the cards are divided into drawers: A-C, D-F, etc. An index has a "master drawer" with A-J on the left side, and K-Z on the right.
These master cards point to a second index drawer. If looking for "Charles", the second drawer would contain cards for C on the left and D on the right.
So, by looking in the first drawer, the database eliminates all of the drawers but one, making the search much faster.
Similar?
But it doesn't seem to me practical to apply such a method here.
#17
![Default](/forum/images/icons/icon1.gif)
I'm afraid the "binary search" idea isn't so easy to apply here. If there were, say, 128 independent fuses, then the drill would be to pull half of them (64) and see if the problem went away. Whether it did or dd not, we would have narrowed the search to 64 fuses. On it would go: 32, 16, 8, 4, 2, 1.
But it doesn't seem to me practical to apply such a method here.
But it doesn't seem to me practical to apply such a method here.
Last edited by WhiteXKR; 11-17-2011 at 12:59 PM.
#18
#19
![Default](/forum/images/icons/icon1.gif)
How would one do this? Are there plugs into each block?
(My knowledge of automobile electronics is evolving. And BROTHER is there a lot of evolutionary potential here.)
![Smile](https://www.jaguarforums.com/forum/images/smilies/smile.gif)
#20
![Default](/forum/images/icons/icon1.gif)
Each fusebox has a heavy B+ lead with a lug terminal that can be disconnected (very carefully...it is not something you want to accidently short to the chassis unless you want to weld it there!)
The following users liked this post:
mcbeefsteak (11-18-2011)