Hey there if anyone can help me i'd greatly appreciate it..
I'm an auto tech who knows nothing about car systems, but any way i have a 1998 ford expedition i'm working on with a battery drain when the truck is off. There has been a new head unit installed and two amps with a small battery to the amp. I pretty sure that this expedition had a ford premium sound system in it before, which means it too had an amp. If this amp isn't jumped won't it cause a battery drain? or is the drain possibly coming from somewhere else?
Replies (10)
ttocs on 11/15/2005 08:50:43
What about that small battery? Does it have an isolator on it? IF you hook two batteries together I thought they had to be the same, I mean bought on the same day as well as be isolated to keep them from cycling dry?
have you hooked an amp meter up to the battery and started pulling fuses? I have seen all kinds of things but you do need to narrow it down first. The factory system could be bypassed with a bypass hrns, the amp is behind the passenger side rear trim. even if it is wired into it, that shouldn't cause a drain. There should be a fuse labeled "premium sound" in the interior fuse box, pull it and see if you have sound........
swez on 11/15/2005 10:33:38
Was thinking the same thing here. Find out how much current drain there is in the system. Then, start pulling fuses until that drain is eliminated.
I would start at that 2nd battery. If your drain stops there, that's the culprit. Also, the 2nd battery may be acting as a load (drain) on the main BAT. (they are trying to equalize)
Do you know how to test amperage draw (parasitic drain) with an ammeter?
With the key out and meter installed in series between BAT + terminal and BAT + wire connector, I would not expect to see more than a few milli-amps draw from clock, HU memory and maybe ECM. If there is more, then start your fuse pulling process to find the circuit that is causing the big drain.
With the key in and set to ACC or IGN, I would expect a higher current draw number as now, dash lamps, ECM and a host of other circuits will be activated as well as amplifiers, if the HU is already on.
Finally, how old is the main BAT? After 3-4 winters, most stock BATs will begin to age and short out some of the plates. This is the death nell of a battery. These shorts will drain the BAT over time. A charging test will tell as will testing the electrolytes (specific gravity) in each cell. If one or more cells are reading very low SG, the battery is on its way out.
Swez
bearblu2 on 11/15/2005 23:41:05
I disconnected the battery negative cable and connected my test light in series with the negative cable to the negative terminal. It remained lit until I pulled the radio fuse. I replaced the fuse and then removed the small battery and reconnected everything without the small battery. My test light still remained on. I'm still clueless as to were my drain in the radio system is. Far as I can tell this guy just wired his speakers directly from the factory speaker wire to the amps. Does anyone know if not having the ford amplifier integrated or bypassed if it will cause this much drain? I have no clue what to try next. Please help!!!!
bearblu2 on 11/15/2005 23:43:38
forgot to add that this supposedly the third battery in six months.
swez on 11/16/2005 08:49:36
Egads! This means he has a real problem with current draining the battery to a point that is dies in short order.
Have you checked his amps out to see if the power lamps remain on while the key is off? If yes, they have a modest idle current draw and in time, can drain a battery. They should only have power flowing when the HU is turned on and the REMote wire triggers the amps to on mode.
This definitely points to the HU circuit and other related components. The question is, how much current is actually being drained and by what devices. The lamp test proves there is current flow in that circuit until the fuse was pulled. The amount of current draw can be determined via an ammeter.
Wait for additional inputs from our installers. They may have some tips on wiring and bypass circuits you can look at. Wish I could help you more. But at the moment, my experience with OEM amping systems are limited.
Swez
ttocs on 11/16/2005 15:17:43
sounds like the radio is the source of the drain. I had a customer complain that his radio was draining the battery. After some work I found out that the cd changer was staying on and shuttling cd's back and forth constantly, slowly draining the battery. Are the amps staying on? Is this a factory radio?
bearblu2 on 11/17/2005 00:28:26
bearblu2 on 11/17/2005 00:35:17
Here is the scoop. I took apart the center console to get to the ford amp. I disconnected the two plugs to the ford amp and watched my test light slowly fade off. So i think I've found my culprit. What a beautiful thing. My questions now are if I integrate the ford amplifier into the system will it affect the other two amps or the rest of the system. Is there a way to bypass the ford sysytem and how do I do it?
ttocs on 11/17/2005 11:16:31
that sounds like it is it. Did the sound go out as well as the light? If not then you don't need to do anything. If the sound did stop then you can get a bypass hrns from a local shop. If you have added an aftermarket deck or amp you don't want to use the factory amp....
swez on 11/17/2005 11:26:29
Ahhhh, the amp(s) are staying on all the time here and causing the drain. Good detective work! There is usually a trigger signal from the OEM HU that tells the amps to turn on and off with the HU. That appearns not to be working correctly anymore.
Most guys just swap out the OEM HU for an Aftermarket one and run RCA's to outboard amps and Aftermarket speakers. This bypasses the OEM amplifiers. That means new speaker wire lines are in order as well. (unless you splice into the OEM speaker harnesses) They need to be disconnected from the OEM amps too.
In this way, you can bypass the OEM system, leave it all in tact and run Aftermarket gear to enjoy. When selling the vehicle, just reconnect the OEM HU/amps, reinstall the OEM speakers and keep your gear for the next install.
It may be a good idea to document the steps in pics and such, so he remembers how all was done prior and can refit back to OEM later w/o a lot of guess work. A Video camera (taped documentation) would be a good option.
Swez
I'm an auto tech who knows nothing about car systems, but any way i have a 1998 ford expedition i'm working on with a battery drain when the truck is off. There has been a new head unit installed and two amps with a small battery to the amp. I pretty sure that this expedition had a ford premium sound system in it before, which means it too had an amp. If this amp isn't jumped won't it cause a battery drain? or is the drain possibly coming from somewhere else?
Replies (10)
ttocs on 11/15/2005 08:50:43
What about that small battery? Does it have an isolator on it? IF you hook two batteries together I thought they had to be the same, I mean bought on the same day as well as be isolated to keep them from cycling dry?
have you hooked an amp meter up to the battery and started pulling fuses? I have seen all kinds of things but you do need to narrow it down first. The factory system could be bypassed with a bypass hrns, the amp is behind the passenger side rear trim. even if it is wired into it, that shouldn't cause a drain. There should be a fuse labeled "premium sound" in the interior fuse box, pull it and see if you have sound........
swez on 11/15/2005 10:33:38
Was thinking the same thing here. Find out how much current drain there is in the system. Then, start pulling fuses until that drain is eliminated.
I would start at that 2nd battery. If your drain stops there, that's the culprit. Also, the 2nd battery may be acting as a load (drain) on the main BAT. (they are trying to equalize)
Do you know how to test amperage draw (parasitic drain) with an ammeter?
With the key out and meter installed in series between BAT + terminal and BAT + wire connector, I would not expect to see more than a few milli-amps draw from clock, HU memory and maybe ECM. If there is more, then start your fuse pulling process to find the circuit that is causing the big drain.
With the key in and set to ACC or IGN, I would expect a higher current draw number as now, dash lamps, ECM and a host of other circuits will be activated as well as amplifiers, if the HU is already on.
Finally, how old is the main BAT? After 3-4 winters, most stock BATs will begin to age and short out some of the plates. This is the death nell of a battery. These shorts will drain the BAT over time. A charging test will tell as will testing the electrolytes (specific gravity) in each cell. If one or more cells are reading very low SG, the battery is on its way out.
Swez
bearblu2 on 11/15/2005 23:41:05
I disconnected the battery negative cable and connected my test light in series with the negative cable to the negative terminal. It remained lit until I pulled the radio fuse. I replaced the fuse and then removed the small battery and reconnected everything without the small battery. My test light still remained on. I'm still clueless as to were my drain in the radio system is. Far as I can tell this guy just wired his speakers directly from the factory speaker wire to the amps. Does anyone know if not having the ford amplifier integrated or bypassed if it will cause this much drain? I have no clue what to try next. Please help!!!!
bearblu2 on 11/15/2005 23:43:38
forgot to add that this supposedly the third battery in six months.
swez on 11/16/2005 08:49:36
Egads! This means he has a real problem with current draining the battery to a point that is dies in short order.
Have you checked his amps out to see if the power lamps remain on while the key is off? If yes, they have a modest idle current draw and in time, can drain a battery. They should only have power flowing when the HU is turned on and the REMote wire triggers the amps to on mode.
This definitely points to the HU circuit and other related components. The question is, how much current is actually being drained and by what devices. The lamp test proves there is current flow in that circuit until the fuse was pulled. The amount of current draw can be determined via an ammeter.
Wait for additional inputs from our installers. They may have some tips on wiring and bypass circuits you can look at. Wish I could help you more. But at the moment, my experience with OEM amping systems are limited.
Swez
ttocs on 11/16/2005 15:17:43
sounds like the radio is the source of the drain. I had a customer complain that his radio was draining the battery. After some work I found out that the cd changer was staying on and shuttling cd's back and forth constantly, slowly draining the battery. Are the amps staying on? Is this a factory radio?
bearblu2 on 11/17/2005 00:28:26
bearblu2 on 11/17/2005 00:35:17
Here is the scoop. I took apart the center console to get to the ford amp. I disconnected the two plugs to the ford amp and watched my test light slowly fade off. So i think I've found my culprit. What a beautiful thing. My questions now are if I integrate the ford amplifier into the system will it affect the other two amps or the rest of the system. Is there a way to bypass the ford sysytem and how do I do it?
ttocs on 11/17/2005 11:16:31
that sounds like it is it. Did the sound go out as well as the light? If not then you don't need to do anything. If the sound did stop then you can get a bypass hrns from a local shop. If you have added an aftermarket deck or amp you don't want to use the factory amp....
swez on 11/17/2005 11:26:29
Ahhhh, the amp(s) are staying on all the time here and causing the drain. Good detective work! There is usually a trigger signal from the OEM HU that tells the amps to turn on and off with the HU. That appearns not to be working correctly anymore.
Most guys just swap out the OEM HU for an Aftermarket one and run RCA's to outboard amps and Aftermarket speakers. This bypasses the OEM amplifiers. That means new speaker wire lines are in order as well. (unless you splice into the OEM speaker harnesses) They need to be disconnected from the OEM amps too.
In this way, you can bypass the OEM system, leave it all in tact and run Aftermarket gear to enjoy. When selling the vehicle, just reconnect the OEM HU/amps, reinstall the OEM speakers and keep your gear for the next install.
It may be a good idea to document the steps in pics and such, so he remembers how all was done prior and can refit back to OEM later w/o a lot of guess work. A Video camera (taped documentation) would be a good option.
Swez
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