So why can't we use the cigarette lighter as a power port?
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From: Northern VA
So why can't we use the cigarette lighter as a power port?
The owner's manual states in bold print "DO NOT" use the cigarette lighter as a power point. Yet I see people claim to use it all the time on here, and when I plug accessory devices in they seem to work just fine. What gives? Is there not a fuse on that circuit? Fire hazard?
CLP Capacity
I believe that this could be an answer. After checking on the circuit wiring for these vehicles I notice that the circuit, wiring of the leads up to the CLP is somewhat inadequate for circuit loads that would be equivalent to more than 7-10 Amps. DC or R.M.S safely in spite of the fused rating.
Since most small devices for intermittent use in the vehicle are usually drawing around 10 to 20% of this figure they usually do not have too much problem with the exception of a direct short in the cable. However there is a difference within the socket of a "cigarette lighter socket" from the socket usually found in most electronic shops for powered accessories.
The CLS has an internal clamp which extends upward from the bottom of the socket which connects with the internal heating element of the CLP. This is not found in the "power socket" usually found in Radio Shack,Poop Boys, e.t.c since this is not usually required to clamp the heater electrode of the CLP. There have been tendencies in some instances for shorting out of the socket by some types of store bought CLP;s when used with a OEM cig socket. This is because there could be a short between the clamp connect (+) at the bottom of the socket with the ground contacts of the CLP when inserted. For the opposite reason it is not wise to use a cigarette lighter plug with a "power plug" since it too could short out at the bottom of the socket. Additionally if it were to work the heat generated in the CLP could melt or burn the socket to cause damage.
I would not trust any OEM or additional "power socket" with any more than 5 Amps on a continual or long term basis. Instead I would route a fused cable lead directly from the battery if I needed more than 10A of current.
That is my opinion based on what I had observed.
Since most small devices for intermittent use in the vehicle are usually drawing around 10 to 20% of this figure they usually do not have too much problem with the exception of a direct short in the cable. However there is a difference within the socket of a "cigarette lighter socket" from the socket usually found in most electronic shops for powered accessories.
The CLS has an internal clamp which extends upward from the bottom of the socket which connects with the internal heating element of the CLP. This is not found in the "power socket" usually found in Radio Shack,Poop Boys, e.t.c since this is not usually required to clamp the heater electrode of the CLP. There have been tendencies in some instances for shorting out of the socket by some types of store bought CLP;s when used with a OEM cig socket. This is because there could be a short between the clamp connect (+) at the bottom of the socket with the ground contacts of the CLP when inserted. For the opposite reason it is not wise to use a cigarette lighter plug with a "power plug" since it too could short out at the bottom of the socket. Additionally if it were to work the heat generated in the CLP could melt or burn the socket to cause damage.
I would not trust any OEM or additional "power socket" with any more than 5 Amps on a continual or long term basis. Instead I would route a fused cable lead directly from the battery if I needed more than 10A of current.
That is my opinion based on what I had observed.
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From: Memphis, TN 38135, USA, Earth
The shape of the contacts in the cigar lighter socket aren't optimized for power adapters, so they can blow the fuse. And since Ford used that same fuse (on some years) for OBD-II functions, you can shut down or damage the engine if you blow it while driving.
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Hmm, those sound like pretty good reasons to heed the warning in the owner's manual. Thanks for your replies!
Looking at the manual some more, I only see one fuse for the "cigarette lighter" listed at 20 amps. I don't see another fuse for a separate circuit for the power point. Does that mean the 20 amps is shared between both the lighter and power point? Which would mean blowing the fuse with something plugged into the power point would be just as harmful to the OBD-II functions as blowing the fuse by using the cig lighter? I presume the risk of blowing the fuse is just higher when using the cig lighter because of its unique features and less-than-ideal receptacle?
Looking at the manual some more, I only see one fuse for the "cigarette lighter" listed at 20 amps. I don't see another fuse for a separate circuit for the power point. Does that mean the 20 amps is shared between both the lighter and power point? Which would mean blowing the fuse with something plugged into the power point would be just as harmful to the OBD-II functions as blowing the fuse by using the cig lighter? I presume the risk of blowing the fuse is just higher when using the cig lighter because of its unique features and less-than-ideal receptacle?
Last edited by BMWBig6; Aug 30, 2007 at 07:06 AM.
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From: CHARLESTON, SC
The CLP/OBD fuse in question does not power any internal engine/OBD functions. It only supplies power to the code reader that is plugged into the data link port (at least that is the way it is on my 01 Eccursion). Unfortunately, I didn't see the warning about not using it as a power point and I used it for several years. Finally, the CLP partially shorted out and drew about 5 Amps with nothing plugged into it. I guess it couldn't stand providing 10-15 Amps for hours at a time. Anyway, I learned my lesson. The only thing I plug into it now is a cell phone charger.
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From: Panama City, FL
I think the reason for this is that the cigarette lighter is an "always-on" power source. The power point is switched on and off by the ignition. If you are charging an accessory from the lighter, when you shut off the truck and go inside for the night, the accessory will use your battery to continue charging. Depending on what kind of accessory that is, it might leave you with a dead battery in the morning.
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Originally Posted by Steve83
The shape of the contacts in the cigar lighter socket aren't optimized for power adapters, so they can blow the fuse. And since Ford used that same fuse (on some years) for OBD-II functions, you can shut down or damage the engine if you blow it while driving.
Last edited by Cynder; Sep 6, 2007 at 11:32 PM.
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From: concord, nc
Originally Posted by 98Expedition10
I believe that this could be an answer. After checking on the circuit wiring for these vehicles I notice that the circuit, wiring of the leads up to the CLP is somewhat inadequate for circuit loads that would be equivalent to more than 7-10 Amps. DC or R.M.S safely in spite of the fused rating.
Since most small devices for intermittent use in the vehicle are usually drawing around 10 to 20% of this figure they usually do not have too much problem with the exception of a direct short in the cable. However there is a difference within the socket of a "cigarette lighter socket" from the socket usually found in most electronic shops for powered accessories.
The CLS has an internal clamp which extends upward from the bottom of the socket which connects with the internal heating element of the CLP. This is not found in the "power socket" usually found in Radio Shack,Poop Boys, e.t.c since this is not usually required to clamp the heater electrode of the CLP. There have been tendencies in some instances for shorting out of the socket by some types of store bought CLP;s when used with a OEM cig socket. This is because there could be a short between the clamp connect (+) at the bottom of the socket with the ground contacts of the CLP when inserted. For the opposite reason it is not wise to use a cigarette lighter plug with a "power plug" since it too could short out at the bottom of the socket. Additionally if it were to work the heat generated in the CLP could melt or burn the socket to cause damage.
I would not trust any OEM or additional "power socket" with any more than 5 Amps on a continual or long term basis. Instead I would route a fused cable lead directly from the battery if I needed more than 10A of current.
That is my opinion based on what I had observed.
Since most small devices for intermittent use in the vehicle are usually drawing around 10 to 20% of this figure they usually do not have too much problem with the exception of a direct short in the cable. However there is a difference within the socket of a "cigarette lighter socket" from the socket usually found in most electronic shops for powered accessories.
The CLS has an internal clamp which extends upward from the bottom of the socket which connects with the internal heating element of the CLP. This is not found in the "power socket" usually found in Radio Shack,Poop Boys, e.t.c since this is not usually required to clamp the heater electrode of the CLP. There have been tendencies in some instances for shorting out of the socket by some types of store bought CLP;s when used with a OEM cig socket. This is because there could be a short between the clamp connect (+) at the bottom of the socket with the ground contacts of the CLP when inserted. For the opposite reason it is not wise to use a cigarette lighter plug with a "power plug" since it too could short out at the bottom of the socket. Additionally if it were to work the heat generated in the CLP could melt or burn the socket to cause damage.
I would not trust any OEM or additional "power socket" with any more than 5 Amps on a continual or long term basis. Instead I would route a fused cable lead directly from the battery if I needed more than 10A of current.
That is my opinion based on what I had observed.
