Dummy light meanings
09-29-2011, 05:37 PM
#1
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Year: 96
Model: Cherokee
Engine: I6
Dummy light meanings
Just bought a 96 XJ 5spd on 33's and i'm already in love with it.
But it didn't come with a manual and internets searches have left me dry.
When i'm driving a yellow arrow pointing up sometimes appears on the dummy light cluster. What is this warning?
Also is there a list or website explaining the rest of the symbols i might see?
i feel this is important to know seeing that it is used and may have some problems that need addressing.
Thanks guys
But it didn't come with a manual and internets searches have left me dry.
When i'm driving a yellow arrow pointing up sometimes appears on the dummy light cluster. What is this warning?
Also is there a list or website explaining the rest of the symbols i might see?
i feel this is important to know seeing that it is used and may have some problems that need addressing.
Thanks guys
09-29-2011, 06:50 PM
#3
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Year: 1988
Model: Cherokee
Engine: AMC242
2) No. It thinks it gives you better fuel mileage, but it probably won't.
Assuming you have the 6-242 and stock gearing and close to OEM tyres, try this:
- Ignore that silly little lamp. Remove it when you get the chance (no harm will befall you if you do this - it's not a "fault lamp," it's merely an "operator advisory.")
- Maintain cruising RPM around 2600-3000rpm on the tach. This probably means you won't be using fifth gear for anything - this is fine.
- Compare fuel mileage if you "listen to the light," vice if you set your own shift points by engine RPM.
Chances are good you'll note better fuel mileage once you stop using fifth gear. Why? Because the 3.07 axle gearing used with the 6-242 and manual transmission (whichever one - BA-10, AX-15i, AX-15e, or NV3550) is a horrible complement. They would have been better off using gearing around 3.73:1.
As anyone with a G/A pilot's license can tell you, an engine runs most efficiently at or near the point where it makes peak torque. Also, you would note (if you compared the charts yourself,) that the curves for torque output and volumetric efficiency (actual airflow vice theoretical airflow) follow each other rather closely.
Any light aircraft pilot will tell you that you don't get peak cruise range from running at a low rpm, but from running at or near peak torque. This is why knowing the engine output curves is part of being type-certified on aircraft.
Merketing has bumfoozled people into thinking that "low engine rpm = high fuel efficiency,) but it just ain't so. Then, marketing & design have perpetuated that erratum in two ways:
- They have required the installation of the "upshift" lamp, set at a low RPM.
- They have marketed their engines based on horsepower output (which is always above 5,000 rpm for peak output) vice torque output (which is more useful in a truck anyhow, and will always take place below 5,252 rpm. Typically, down around 2500-3000rpm, if the engine is designed properly for light truck use.)
This irritates me to no end, the fact that marketing thinks that they can hold the laws of physics, thermodynamics, and fluid dynamics in abeyance simply because they wish it to be so. Then they jump all over engineering when it don't happen (because it can't happen.)
We'd all be better off if we could get marketing, accounting, and legal to stay the Hell out of engineering - let the engineers get on with their work, and legal would be happy (and marketing and accounting would just have to learn to deal with it.)
09-30-2011, 03:34 AM
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Year: 96
Model: Cherokee
Engine: I6
Calm down 5-90 haha it will be ok.
Thanks both of you. I thought that was what it was for, seemed odd to me it was telling me to upshift at 1500rpm though, it almost made me bog out when i obeyed it, i use engine sound and feel instead for shifting usually. Most times i shift in between 2500 and 3k.
What about the rest of the dummy lights? I don't have a owners manual. What lights are there besides the 4X4 part time/low lights?
any references would be great.
Thanks both of you. I thought that was what it was for, seemed odd to me it was telling me to upshift at 1500rpm though, it almost made me bog out when i obeyed it, i use engine sound and feel instead for shifting usually. Most times i shift in between 2500 and 3k.
What about the rest of the dummy lights? I don't have a owners manual. What lights are there besides the 4X4 part time/low lights?
any references would be great.
09-30-2011, 09:17 AM
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Year: 1995
Model: Cherokee
Engine: 4.0
top bar-- parking brakes & brake system warning
2nd bar-- 4wd indicator
3rd bar-- seatbelt warning
4th bar-- check engine & windshield washer fluid low warning
5th bar-- shift indicator & brakes ABS warning
this is out of my 95 manual...hope it helps
2nd bar-- 4wd indicator
3rd bar-- seatbelt warning
4th bar-- check engine & windshield washer fluid low warning
5th bar-- shift indicator & brakes ABS warning
this is out of my 95 manual...hope it helps
09-30-2011, 09:33 AM
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Year: 1998
Model: Cherokee
Engine: 4.0 stock
1) Yes.
2) No. It thinks it gives you better fuel mileage, but it probably won't.
Assuming you have the 6-242 and stock gearing and close to OEM tyres, try this:
- Ignore that silly little lamp. Remove it when you get the chance (no harm will befall you if you do this - it's not a "fault lamp," it's merely an "operator advisory.")
- Maintain cruising RPM around 2600-3000rpm on the tach. This probably means you won't be using fifth gear for anything - this is fine.
- Compare fuel mileage if you "listen to the light," vice if you set your own shift points by engine RPM.
Chances are good you'll note better fuel mileage once you stop using fifth gear. Why? Because the 3.07 axle gearing used with the 6-242 and manual transmission (whichever one - BA-10, AX-15i, AX-15e, or NV3550) is a horrible complement. They would have been better off using gearing around 3.73:1.
As anyone with a G/A pilot's license can tell you, an engine runs most efficiently at or near the point where it makes peak torque. Also, you would note (if you compared the charts yourself,) that the curves for torque output and volumetric efficiency (actual airflow vice theoretical airflow) follow each other rather closely.
Any light aircraft pilot will tell you that you don't get peak cruise range from running at a low rpm, but from running at or near peak torque. This is why knowing the engine output curves is part of being type-certified on aircraft.
Merketing has bumfoozled people into thinking that "low engine rpm = high fuel efficiency,) but it just ain't so. Then, marketing & design have perpetuated that erratum in two ways:
- They have required the installation of the "upshift" lamp, set at a low RPM.
- They have marketed their engines based on horsepower output (which is always above 5,000 rpm for peak output) vice torque output (which is more useful in a truck anyhow, and will always take place below 5,252 rpm. Typically, down around 2500-3000rpm, if the engine is designed properly for light truck use.)
This irritates me to no end, the fact that marketing thinks that they can hold the laws of physics, thermodynamics, and fluid dynamics in abeyance simply because they wish it to be so. Then they jump all over engineering when it don't happen (because it can't happen.)
We'd all be better off if we could get marketing, accounting, and legal to stay the Hell out of engineering - let the engineers get on with their work, and legal would be happy (and marketing and accounting would just have to learn to deal with it.)
2) No. It thinks it gives you better fuel mileage, but it probably won't.
Assuming you have the 6-242 and stock gearing and close to OEM tyres, try this:
- Ignore that silly little lamp. Remove it when you get the chance (no harm will befall you if you do this - it's not a "fault lamp," it's merely an "operator advisory.")
- Maintain cruising RPM around 2600-3000rpm on the tach. This probably means you won't be using fifth gear for anything - this is fine.
- Compare fuel mileage if you "listen to the light," vice if you set your own shift points by engine RPM.
Chances are good you'll note better fuel mileage once you stop using fifth gear. Why? Because the 3.07 axle gearing used with the 6-242 and manual transmission (whichever one - BA-10, AX-15i, AX-15e, or NV3550) is a horrible complement. They would have been better off using gearing around 3.73:1.
As anyone with a G/A pilot's license can tell you, an engine runs most efficiently at or near the point where it makes peak torque. Also, you would note (if you compared the charts yourself,) that the curves for torque output and volumetric efficiency (actual airflow vice theoretical airflow) follow each other rather closely.
Any light aircraft pilot will tell you that you don't get peak cruise range from running at a low rpm, but from running at or near peak torque. This is why knowing the engine output curves is part of being type-certified on aircraft.
Merketing has bumfoozled people into thinking that "low engine rpm = high fuel efficiency,) but it just ain't so. Then, marketing & design have perpetuated that erratum in two ways:
- They have required the installation of the "upshift" lamp, set at a low RPM.
- They have marketed their engines based on horsepower output (which is always above 5,000 rpm for peak output) vice torque output (which is more useful in a truck anyhow, and will always take place below 5,252 rpm. Typically, down around 2500-3000rpm, if the engine is designed properly for light truck use.)
This irritates me to no end, the fact that marketing thinks that they can hold the laws of physics, thermodynamics, and fluid dynamics in abeyance simply because they wish it to be so. Then they jump all over engineering when it don't happen (because it can't happen.)
We'd all be better off if we could get marketing, accounting, and legal to stay the Hell out of engineering - let the engineers get on with their work, and legal would be happy (and marketing and accounting would just have to learn to deal with it.)
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