Weird electrical problem (dash and tail lights)
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Weird electrical problem (dash and tail lights)
My daughter's 85 firebird has a weird problem I need to fix ASAP, any help is appreciated.
The headlights flip up and work, as do the brake lights. However, the dash and the tail lights stopped lighting up.
I don't think it's a fuse issue, unless I missed something. If it's the on/off switch, how screwed am I?
I am open to any suggestions.
John
The headlights flip up and work, as do the brake lights. However, the dash and the tail lights stopped lighting up.
I don't think it's a fuse issue, unless I missed something. If it's the on/off switch, how screwed am I?
I am open to any suggestions.
John
Joined: Sep 2005
Posts: 27,867
Likes: 2,428
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Weird electrical problem (dash and tail lights)
The tail lights and dash lights are both fed from the same terminal of the headlight switch. It's probably that switch.
Not sure about "screwed"... it's cheeeeeeeep and fairly eeeeezy to replace, but beyond that, ??
Not sure about "screwed"... it's cheeeeeeeep and fairly eeeeezy to replace, but beyond that, ??
Junior Member
Joined: Jul 2014
Posts: 14
Likes: 0
Re: Weird electrical problem (dash and tail lights)
My daughter's 85 firebird has a weird problem I need to fix ASAP, any help is appreciated.
The headlights flip up and work, as do the brake lights. However, the dash and the tail lights stopped lighting up.
I don't think it's a fuse issue, unless I missed something. If it's the on/off switch, how screwed am I?
I am open to any suggestions.
John
The headlights flip up and work, as do the brake lights. However, the dash and the tail lights stopped lighting up.
I don't think it's a fuse issue, unless I missed something. If it's the on/off switch, how screwed am I?
I am open to any suggestions.
John
Joined: Sep 2005
Posts: 27,867
Likes: 2,428
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Weird electrical problem (dash and tail lights)
There is no fuse that can create the symptoms at hand.
Note that I am NOT saying "all the fuses are good", "don't check the fuses", "fuses always look bad when they blow", etc.; so DON'T accuse me of any of that. What I AM saying is, it is PHYSICALLY IMPOSSIBLE for A fuse to kill both the taillights and instrument lights. It would require TWO fuses to have failed, AT THE SAME TIME; highly unlikely to say the least.
The ONE THING that CAN cause BOTH OF the symptoms at hand, is the headlight switch. (or of course, the wiring that connects to its terminals)
If there's any one thing I've learned in 45 yrs of troubleshooting electric and electronic eqpt it is, that about 99.999% of the time, exactly ONE thing has failed, not MULTIPLE things, even at the beginning of a "failure cascade". It's always possible of course that when the ONE thing failed, it TOOK OUT others; but obviously one fuse blowing can't cause others to blow though. And even if MULTIPLE things have indeed failed, there is virtually always a SINGLE root cause: might be a lightning strike (20 of those yrs were as a radio & TV station chief engineer, so I know more about lightning than most people), might be user error, might be a mouse chewed through the wires, might be a foreign substance spilled in it, might just be a component got old and failed, and so forth; but regardless, there is ONE SINGLE root cause. In order to fix the problem permanently, one MUST find and remedy the root cause. (add ball gaps, educate the user, kill the varmint and repair the bare wires that are shorting to bare metal, clean up the mess, find the ONE part that failed and then killed the others, etc.)
See my signature for an ancient and succinct distillation of this mental principle.
Note that I am NOT saying "all the fuses are good", "don't check the fuses", "fuses always look bad when they blow", etc.; so DON'T accuse me of any of that. What I AM saying is, it is PHYSICALLY IMPOSSIBLE for A fuse to kill both the taillights and instrument lights. It would require TWO fuses to have failed, AT THE SAME TIME; highly unlikely to say the least.
The ONE THING that CAN cause BOTH OF the symptoms at hand, is the headlight switch. (or of course, the wiring that connects to its terminals)
If there's any one thing I've learned in 45 yrs of troubleshooting electric and electronic eqpt it is, that about 99.999% of the time, exactly ONE thing has failed, not MULTIPLE things, even at the beginning of a "failure cascade". It's always possible of course that when the ONE thing failed, it TOOK OUT others; but obviously one fuse blowing can't cause others to blow though. And even if MULTIPLE things have indeed failed, there is virtually always a SINGLE root cause: might be a lightning strike (20 of those yrs were as a radio & TV station chief engineer, so I know more about lightning than most people), might be user error, might be a mouse chewed through the wires, might be a foreign substance spilled in it, might just be a component got old and failed, and so forth; but regardless, there is ONE SINGLE root cause. In order to fix the problem permanently, one MUST find and remedy the root cause. (add ball gaps, educate the user, kill the varmint and repair the bare wires that are shorting to bare metal, clean up the mess, find the ONE part that failed and then killed the others, etc.)
See my signature for an ancient and succinct distillation of this mental principle.
Last edited by sofakingdom; Jul 5, 2014 at 09:09 AM.
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Re: Weird electrical problem (dash and tail lights)
There is no fuse that can create the symptoms at hand.
Note that I am NOT saying "all the fuses are good", "don't check the fuses", "fuses always look bad when they blow", etc.; so DON'T accuse me of any of that. What I AM saying is, it is PHYSICALLY IMPOSSIBLE for A fuse to kill both the taillights and instrument lights. It would require TWO fuses to have failed, AT THE SAME TIME; highly unlikely to say the least.
The ONE THING that CAN cause BOTH OF the symptoms at hand, is the headlight switch. (or of course, the wiring that connects to its terminals)
If there's any one thing I've learned in 45 yrs of troubleshooting electric and electronic eqpt it is, that about 99.999% of the time, exactly ONE thing has failed, not MULTIPLE things, even at the beginning of a "failure cascade". It's always possible of course that when the ONE thing failed, it TOOK OUT others; but obviously one fuse blowing can't cause others to blow though. And even if MULTIPLE things have indeed failed, there is virtually always a SINGLE root cause: might be a lightning strike (20 of those yrs were as a radio & TV station chief engineer, so I know more about lightning than most people), might be user error, might be a mouse chewed through the wires, might be a foreign substance spilled in it, might just be a component got old and failed, and so forth; but regardless, there is ONE SINGLE root cause. In order to fix the problem permanently, one MUST find and remedy the root cause. (add ball gaps, educate the user, kill the varmint and repair the bare wires that are shorting to bare metal, clean up the mess, find the ONE part that failed and then killed the others, etc.)
See my signature for an ancient and succinct distillation of this mental principle.
Note that I am NOT saying "all the fuses are good", "don't check the fuses", "fuses always look bad when they blow", etc.; so DON'T accuse me of any of that. What I AM saying is, it is PHYSICALLY IMPOSSIBLE for A fuse to kill both the taillights and instrument lights. It would require TWO fuses to have failed, AT THE SAME TIME; highly unlikely to say the least.
The ONE THING that CAN cause BOTH OF the symptoms at hand, is the headlight switch. (or of course, the wiring that connects to its terminals)
If there's any one thing I've learned in 45 yrs of troubleshooting electric and electronic eqpt it is, that about 99.999% of the time, exactly ONE thing has failed, not MULTIPLE things, even at the beginning of a "failure cascade". It's always possible of course that when the ONE thing failed, it TOOK OUT others; but obviously one fuse blowing can't cause others to blow though. And even if MULTIPLE things have indeed failed, there is virtually always a SINGLE root cause: might be a lightning strike (20 of those yrs were as a radio & TV station chief engineer, so I know more about lightning than most people), might be user error, might be a mouse chewed through the wires, might be a foreign substance spilled in it, might just be a component got old and failed, and so forth; but regardless, there is ONE SINGLE root cause. In order to fix the problem permanently, one MUST find and remedy the root cause. (add ball gaps, educate the user, kill the varmint and repair the bare wires that are shorting to bare metal, clean up the mess, find the ONE part that failed and then killed the others, etc.)
See my signature for an ancient and succinct distillation of this mental principle.
At this point you don't know if power is on the dash, or if your ground is bad. Time to find a wiring diagram well if you have ground at the lighter then the dash has ground, but maybe not on your car
Joined: Sep 2005
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Car: Yes
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Re: Weird electrical problem (dash and tail lights)
Headlight switch first
Look for the ONE THING that creates the SIMPLEST explanation with the fewest "moving parts", the least "odd coincidences", stays away from "never seen this before", avoids alien abduction and dark matter and the hemorrhaging edge of quantum cosmology, etc.
Which in this case is, the headlight switch. Real simple: one contact in the switch goes bad, and the taillights and dash lights BOTH quit working. Doesn't get any simpler than that.
There is no ONE "power" or "ground", on the dash or elsewhere, that can cause the symptoms at hand; other than, the headlight switch.
Start there, at the simple. Move to the more complex only if necessary, and in small steps of the least increase in complexity possible.
Look for the ONE THING that creates the SIMPLEST explanation with the fewest "moving parts", the least "odd coincidences", stays away from "never seen this before", avoids alien abduction and dark matter and the hemorrhaging edge of quantum cosmology, etc.
Which in this case is, the headlight switch. Real simple: one contact in the switch goes bad, and the taillights and dash lights BOTH quit working. Doesn't get any simpler than that.
There is no ONE "power" or "ground", on the dash or elsewhere, that can cause the symptoms at hand; other than, the headlight switch.
Start there, at the simple. Move to the more complex only if necessary, and in small steps of the least increase in complexity possible.
Junior Member
Joined: Jul 2014
Posts: 14
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Re: Weird electrical problem (dash and tail lights)
Headlight switch first
Look for the ONE THING that creates the SIMPLEST explanation with the fewest "moving parts", the least "odd coincidences", stays away from "never seen this before", avoids alien abduction and dark matter and the hemorrhaging edge of quantum cosmology, etc.
Which in this case is, the headlight switch. Real simple: one contact in the switch goes bad, and the taillights and dash lights BOTH quit working. Doesn't get any simpler than that.
There is no ONE "power" or "ground", on the dash or elsewhere, that can cause the symptoms at hand; other than, the headlight switch.
Start there, at the simple. Move to the more complex only if necessary, and in small steps of the least increase in complexity possible.
Look for the ONE THING that creates the SIMPLEST explanation with the fewest "moving parts", the least "odd coincidences", stays away from "never seen this before", avoids alien abduction and dark matter and the hemorrhaging edge of quantum cosmology, etc.
Which in this case is, the headlight switch. Real simple: one contact in the switch goes bad, and the taillights and dash lights BOTH quit working. Doesn't get any simpler than that.
There is no ONE "power" or "ground", on the dash or elsewhere, that can cause the symptoms at hand; other than, the headlight switch.
Start there, at the simple. Move to the more complex only if necessary, and in small steps of the least increase in complexity possible.
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From: Long Island, NY
Car: 1986 Firebird
Engine: 2.8L
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Re: Weird electrical problem (dash and tail lights)
If you think a fuse is bad but don't see a break inside, use an ohmmeter (a voltmeter set to ohms) and put the test leads on each prong or on opposite ends of the fuse and check the meter. ANY working fuse will send the meter to infinity, showing that the "circuit" inside is complete. This type of test will show continuity in any wiring, anywhere. If you put the test leads in the proper positions in any electric circuit, it can be used to find shorts or continuity of the wiring. Good luck on your hunt for a solution!
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