Rx7 fd no rear lights, side lights or indicators
11-20-21, 01:13 PM
#1
Junior Member
Thread Starter
Rx7 fd no rear lights, side lights or indicators
Am after a bit of help, I have no indicators, side lights, brake lights or hazards
1994 rx7 fd
Runs and drives absolutely fine
I have no 12v power to the tns relay
No power at the tail light or hazard fuse on the interior fuse Box
If I put 12v to the tns relay I can use the side lights and brake lights like normal (no indicators or hazards though, however I can hear the flasher unit clicking when using the indicator stalks. No sound when I press the hazard button though)
The wire that is supposed to supply the 12v to the tns relay has good continuity but no power
The ‘trigger wire’ from the stalks to the relay is fine because when I put power to the relay, it switches on the lights.
Bit of an odd one but does anyone have any ideas on what I’ve missed or am doing wrong?
Is this some symptoms of a faulty f100 relay?
1994 rx7 fd
Runs and drives absolutely fine
I have no 12v power to the tns relay
No power at the tail light or hazard fuse on the interior fuse Box
If I put 12v to the tns relay I can use the side lights and brake lights like normal (no indicators or hazards though, however I can hear the flasher unit clicking when using the indicator stalks. No sound when I press the hazard button though)
The wire that is supposed to supply the 12v to the tns relay has good continuity but no power
The ‘trigger wire’ from the stalks to the relay is fine because when I put power to the relay, it switches on the lights.
Bit of an odd one but does anyone have any ideas on what I’ve missed or am doing wrong?
Is this some symptoms of a faulty f100 relay?
11-21-21, 09:27 AM
#2
Is this a North American, European, UK/Australian or Japanese FD? There are some regional differences and I want to make sure you get the correct info. A VIN number would nail it down beyond question. Since you mentioned "F100", I'll assume it is a Japanese FD and the following information is based on this assumption.
Both the 20A Stop and 15A Hazard fuses are fed from the 60A BTN Fusible Link under the hood, via the White/Red wire. Check for continuity between BTN and both fuses. The TNS Relay Pin A (Power pin #30, White/Green) and Pin C (Coil pin #85, White/Green) are both fed from the 15A Tail Lamp fuse, which is also fed from the 60A BTN Fusible Link (check for continuity). Pin D (Coil pin 86, Gray) is ground signal from the Headlight Switch (first position), and Pin B (Power pin #87, Red/Black) is the output to all of the lights it operates (Tail lights, marker lights, dash lights, etc).
It might like a dumb question, but do your Fog Lights work? The power for the Fog Light Relay coil comes from this Red/Black wire too, via the Fog Light Switch. If they're dead too, try swapping out the TNS Relay with a standard Bosch 40A relay using the wiring info above to match the pins up correctly. Wouldn't be the first time a relay went kaput after 20+ years.
Both the 20A Stop and 15A Hazard fuses are fed from the 60A BTN Fusible Link under the hood, via the White/Red wire. Check for continuity between BTN and both fuses. The TNS Relay Pin A (Power pin #30, White/Green) and Pin C (Coil pin #85, White/Green) are both fed from the 15A Tail Lamp fuse, which is also fed from the 60A BTN Fusible Link (check for continuity). Pin D (Coil pin 86, Gray) is ground signal from the Headlight Switch (first position), and Pin B (Power pin #87, Red/Black) is the output to all of the lights it operates (Tail lights, marker lights, dash lights, etc).
It might like a dumb question, but do your Fog Lights work? The power for the Fog Light Relay coil comes from this Red/Black wire too, via the Fog Light Switch. If they're dead too, try swapping out the TNS Relay with a standard Bosch 40A relay using the wiring info above to match the pins up correctly. Wouldn't be the first time a relay went kaput after 20+ years.
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Redbul (11-21-21)
11-25-21, 01:20 AM
#3
I had something similar and had to pull the fuse box inside the car completely out. I had melted the power wire to the box, which only allowed the headlights to work. The fix was a used fuse box and a replacement plug end. If I remember correctly to check it just undo the bolt and use a small mirror to see behind the box or just undo the battery and pull it out.
Last edited by Demonsniper1; 11-25-21 at 01:24 AM.
11-26-21, 08:57 AM
#4
Junior Member
Thread Starter
Is this a North American, European, UK/Australian or Japanese FD? There are some regional differences and I want to make sure you get the correct info. A VIN number would nail it down beyond question. Since you mentioned "F100", I'll assume it is a Japanese FD and the following information is based on this assumption.
Both the 20A Stop and 15A Hazard fuses are fed from the 60A BTN Fusible Link under the hood, via the White/Red wire. Check for continuity between BTN and both fuses. The TNS Relay Pin A (Power pin #30, White/Green) and Pin C (Coil pin #85, White/Green) are both fed from the 15A Tail Lamp fuse, which is also fed from the 60A BTN Fusible Link (check for continuity). Pin D (Coil pin 86, Gray) is ground signal from the Headlight Switch (first position), and Pin B (Power pin #87, Red/Black) is the output to all of the lights it operates (Tail lights, marker lights, dash lights, etc).
It might like a dumb question, but do your Fog Lights work? The power for the Fog Light Relay coil comes from this Red/Black wire too, via the Fog Light Switch. If they're dead too, try swapping out the TNS Relay with a standard Bosch 40A relay using the wiring info above to match the pins up correctly. Wouldn't be the first time a relay went kaput after 20+ years.
Both the 20A Stop and 15A Hazard fuses are fed from the 60A BTN Fusible Link under the hood, via the White/Red wire. Check for continuity between BTN and both fuses. The TNS Relay Pin A (Power pin #30, White/Green) and Pin C (Coil pin #85, White/Green) are both fed from the 15A Tail Lamp fuse, which is also fed from the 60A BTN Fusible Link (check for continuity). Pin D (Coil pin 86, Gray) is ground signal from the Headlight Switch (first position), and Pin B (Power pin #87, Red/Black) is the output to all of the lights it operates (Tail lights, marker lights, dash lights, etc).
It might like a dumb question, but do your Fog Lights work? The power for the Fog Light Relay coil comes from this Red/Black wire too, via the Fog Light Switch. If they're dead too, try swapping out the TNS Relay with a standard Bosch 40A relay using the wiring info above to match the pins up correctly. Wouldn't be the first time a relay went kaput after 20+ years.
continuity between stop +hazard to btn is good
continuity from tns relay pin a+c to tail fuse is good
pin d to earth continuity is good when lights are switched to the first position
pin b still has no power to illuminate anything
I have also fitted a standard relay in place of the tns which unfortunately hasn’t solved the issue.
I have no power at the stop, tail and hazard fuses. I have power at the btn fuse and the fuse is also good
Do you have any other suggestions on what to do next?
Last edited by danwatson64; 11-26-21 at 11:32 AM.
11-26-21, 08:58 AM
#5
Junior Member
Thread Starter
I had something similar and had to pull the fuse box inside the car completely out. I had melted the power wire to the box, which only allowed the headlights to work. The fix was a used fuse box and a replacement plug end. If I remember correctly to check it just undo the bolt and use a small mirror to see behind the box or just undo the battery and pull it out.
*Update*
removed the interior fuse box and checked wires/plugs all seem to be ok, no pushed back pins. Replaced the fuse box with one from another car and still lo lights
Last edited by danwatson64; 11-26-21 at 10:20 AM.
11-26-21, 02:34 PM
#6
Okay, let me recap what's going on so I understand correctly. My apologies for the wordiness, I'm currently fighting off Covid plus a Migraine right now.
At the TNS Relay, Pins A and C, do you have 12v coming from the 15A Tail Lamp Fuse (fed by 60A BTN Fusible Link)? Please note that this is NOT the Stop or Hazard Fuses.
It has been established that the Ground Signal from the Headlight Switch which goes to TNS Relay Pin D is Good, so this is not the problem.
TNS Relay Pin B is the output to lights, it does NOT sound like the issue is here either.
At the same time, you do NOT have 12v at the 15A Hazard Fuse? This is also fed by the 60A BTN Fusible Link and also supplies power to the Horn Relay. Try using the horn, 15A Hazard Fuse has power if the horn works.
The 20A Stop Fuse is fed by the 60A BTN Fusible Link. It goes to the Stop Light Switch, then directly to the Stop Lights. Do you have 12v at the Stop Fuse?
Do you see the pattern here? Things get screwy between the BTN Fusible Link and the Tail, Hazard and Stop Fuses. I'd suggest testing voltage at each one, compared to the Battery. Difference in readings should be 0.1v or less. If you're seeing a bigger difference, such as 10v or less at the three fuses, I'd bet money you have a short to ground which is just conductive enough to knock out the associated circuits, but NOT enough to blow the 60A BTN Fusible Link. A test light would come in handy for this. If you have a spare 194 incandescent bulb, get a pigtail at the parts store (~$3.50) and crimp on some 0.250" Quick Disconnect male terminals. It will be easier to spot the voltage difference with an incandescent bulb instead of an LED one as you can tell by its brightness. LEDs simply won't wake up at anything under 9v, give or take, while a regular filament bulb will illuminate but be incredibly dim all the way down to roughly 6v. Imagine a candle and you'll get what I mean.
I have no 12v power to the tns relay
No power at the tail light or hazard fuse on the interior fuse Box
No power at the tail light or hazard fuse on the interior fuse Box
continuity between stop +hazard to btn is good
continuity from tns relay pin a+c to tail fuse is good
pin d to earth continuity is good when lights are switched to the first position
pin b still has no power to illuminate anything
I have also fitted a standard relay in place of the tns which unfortunately hasn’t solved the issue.
I have no power at the stop, tail and hazard fuses. I have power at the btn fuse and the fuse is also good
Do you have any other suggestions on what to do next?
continuity from tns relay pin a+c to tail fuse is good
pin d to earth continuity is good when lights are switched to the first position
pin b still has no power to illuminate anything
I have also fitted a standard relay in place of the tns which unfortunately hasn’t solved the issue.
I have no power at the stop, tail and hazard fuses. I have power at the btn fuse and the fuse is also good
Do you have any other suggestions on what to do next?
It has been established that the Ground Signal from the Headlight Switch which goes to TNS Relay Pin D is Good, so this is not the problem.
TNS Relay Pin B is the output to lights, it does NOT sound like the issue is here either.
At the same time, you do NOT have 12v at the 15A Hazard Fuse? This is also fed by the 60A BTN Fusible Link and also supplies power to the Horn Relay. Try using the horn, 15A Hazard Fuse has power if the horn works.
The 20A Stop Fuse is fed by the 60A BTN Fusible Link. It goes to the Stop Light Switch, then directly to the Stop Lights. Do you have 12v at the Stop Fuse?
Do you see the pattern here? Things get screwy between the BTN Fusible Link and the Tail, Hazard and Stop Fuses. I'd suggest testing voltage at each one, compared to the Battery. Difference in readings should be 0.1v or less. If you're seeing a bigger difference, such as 10v or less at the three fuses, I'd bet money you have a short to ground which is just conductive enough to knock out the associated circuits, but NOT enough to blow the 60A BTN Fusible Link. A test light would come in handy for this. If you have a spare 194 incandescent bulb, get a pigtail at the parts store (~$3.50) and crimp on some 0.250" Quick Disconnect male terminals. It will be easier to spot the voltage difference with an incandescent bulb instead of an LED one as you can tell by its brightness. LEDs simply won't wake up at anything under 9v, give or take, while a regular filament bulb will illuminate but be incredibly dim all the way down to roughly 6v. Imagine a candle and you'll get what I mean.
11-26-21, 04:06 PM
#7
Junior Member
Thread Starter
Okay, let me recap what's going on so I understand correctly. My apologies for the wordiness, I'm currently fighting off Covid plus a Migraine right now.
At the TNS Relay, Pins A and C, do you have 12v coming from the 15A Tail Lamp Fuse (fed by 60A BTN Fusible Link)? Please note that this is NOT the Stop or Hazard Fuses.
It has been established that the Ground Signal from the Headlight Switch which goes to TNS Relay Pin D is Good, so this is not the problem.
TNS Relay Pin B is the output to lights, it does NOT sound like the issue is here either.
At the same time, you do NOT have 12v at the 15A Hazard Fuse? This is also fed by the 60A BTN Fusible Link and also supplies power to the Horn Relay. Try using the horn, 15A Hazard Fuse has power if the horn works.
The 20A Stop Fuse is fed by the 60A BTN Fusible Link. It goes to the Stop Light Switch, then directly to the Stop Lights. Do you have 12v at the Stop Fuse?
Do you see the pattern here? Things get screwy between the BTN Fusible Link and the Tail, Hazard and Stop Fuses. I'd suggest testing voltage at each one, compared to the Battery. Difference in readings should be 0.1v or less. If you're seeing a bigger difference, such as 10v or less at the three fuses, I'd bet money you have a short to ground which is just conductive enough to knock out the associated circuits, but NOT enough to blow the 60A BTN Fusible Link. A test light would come in handy for this. If you have a spare 194 incandescent bulb, get a pigtail at the parts store (~$3.50) and crimp on some 0.250" Quick Disconnect male terminals. It will be easier to spot the voltage difference with an incandescent bulb instead of an LED one as you can tell by its brightness. LEDs simply won't wake up at anything under 9v, give or take, while a regular filament bulb will illuminate but be incredibly dim all the way down to roughly 6v. Imagine a candle and you'll get what I mean.
At the TNS Relay, Pins A and C, do you have 12v coming from the 15A Tail Lamp Fuse (fed by 60A BTN Fusible Link)? Please note that this is NOT the Stop or Hazard Fuses.
It has been established that the Ground Signal from the Headlight Switch which goes to TNS Relay Pin D is Good, so this is not the problem.
TNS Relay Pin B is the output to lights, it does NOT sound like the issue is here either.
At the same time, you do NOT have 12v at the 15A Hazard Fuse? This is also fed by the 60A BTN Fusible Link and also supplies power to the Horn Relay. Try using the horn, 15A Hazard Fuse has power if the horn works.
The 20A Stop Fuse is fed by the 60A BTN Fusible Link. It goes to the Stop Light Switch, then directly to the Stop Lights. Do you have 12v at the Stop Fuse?
Do you see the pattern here? Things get screwy between the BTN Fusible Link and the Tail, Hazard and Stop Fuses. I'd suggest testing voltage at each one, compared to the Battery. Difference in readings should be 0.1v or less. If you're seeing a bigger difference, such as 10v or less at the three fuses, I'd bet money you have a short to ground which is just conductive enough to knock out the associated circuits, but NOT enough to blow the 60A BTN Fusible Link. A test light would come in handy for this. If you have a spare 194 incandescent bulb, get a pigtail at the parts store (~$3.50) and crimp on some 0.250" Quick Disconnect male terminals. It will be easier to spot the voltage difference with an incandescent bulb instead of an LED one as you can tell by its brightness. LEDs simply won't wake up at anything under 9v, give or take, while a regular filament bulb will illuminate but be incredibly dim all the way down to roughly 6v. Imagine a candle and you'll get what I mean.
the horn doesn’t work either so confirms the no power to the hazard fuse. This only Reads roughly .3v
The stop fuse also reads .3 volts and Tail is also the same with .3v
I’m guessing you are right on the money there with the short to ground.
are there any common places you know of that the wire may have rubbed through? Or is it a case of pulling the casing off the harness and going through it this way?
I will double check the power values I’m getting at the individual fuses and go from there.
Other end of the BTN wire should be at plug jb-05?
headlights also work
Last edited by danwatson64; 11-27-21 at 06:51 AM.
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11-27-21, 08:33 AM
#8
Junior Member
Thread Starter
So I’ve followed the btn wire and it is fine, the end of this seems to go to the chassis harness on the right hand side though? I have 12v at the end of this wire after following it. Is it a possibility that the wiring diagrams being followed is for a left hand drive car and not for the jdm variant?
on the wiring diagram I have it shows the btn wire going to the fuse box? However on this jdm car it goes into the chassis harness
on the wiring diagram I have it shows the btn wire going to the fuse box? However on this jdm car it goes into the chassis harness
11-27-21, 10:13 AM
#9
So I’ve followed the btn wire and it is fine, the end of this seems to go to the chassis harness on the right hand side though? I have 12v at the end of this wire after following it. Is it a possibility that the wiring diagrams being followed is for a left hand drive car and not for the jdm variant?
on the wiring diagram I have it shows the btn wire going to the fuse box? However on this jdm car it goes into the chassis harness
on the wiring diagram I have it shows the btn wire going to the fuse box? However on this jdm car it goes into the chassis harness
Between the BTN Fuse and Tail Lamp Fuse are Connectors X-02, X-11 and JB-05 (Terminal F) again. Output to the lights is JB-04 (Terminal D). Between this and the TNS Relay, it goes through Connector X-11 again.
X-02 is the Fuse Box
X-11 is in the driver footwell, in the Kick Panel area below the Fuse box. It is the connector closest to the door. It connects the FRONT harness to the DASH harness.
JB-xx Connectors are on the back of the Joint Box (Inside fuse box)
Since X-11 is roughly level with the bottom of the Accelerator pedal, I would look there for corrosion first. Also, it may sound like a dumb idea, but you might want to try testing for continuity to Ground at the 3 affected fuses' input terminals. Between X-02 and X-11 AND X-11 to the Joint Box is the White/Red wire for Tail/Hazard/Stop fuses. With the Joint Box disconnected, the goal is to see if this wire has continuity to Ground with the Battery disconnected. One probe at JB-05 Terminal F, one to Chassis ground. It should be Infinite Ohms (no continuity). Note the meter reading here. Now disconnect Connector X-11 and see if it changes. If it jumps to infinite with X-11 unplugged, the bad part is between X-11 (Kick Panel connector) and X-02 (Fuse Box). If it does NOT change, the problem is between X-11 and JB-05.
It's been awhile since I saw one in person, but the Front Harness is routed in a loop in the Engine bay, behind the bodywork to help protect it from the turbos' heat. Start at the Firewall Grommet and follow it. Any iffy spots would likely be near the strut tower due to how close it is to the turbos.
EDIT:
So I did some digging and found this useful thread showing the physical layout of the Front Harness as one would see it on the car. It's for a LHD, but will get you in the ballpark Just imagine X-11 on the opposite side, close to X-05 and you'll get the idea.
https://www.norotors.com/index.php?topic=2468.0
Last edited by Akagis_white_comet; 11-27-21 at 10:20 AM. Reason: Additional Information
11-28-21, 09:58 AM
#10
Junior Member
Thread Starter
From the BTN Fuse, while en route to the Stop and Hazard fuses, it goes through Connectors X-02, X-11 and JB-05 (Terminal F). JB-xx is the Joint Box, AKA inside fuse box. Outputs for Stop and Hazard are JB-05 (Terminal B) and JB-04 (Terminal T) respectively.
Between the BTN Fuse and Tail Lamp Fuse are Connectors X-02, X-11 and JB-05 (Terminal F) again. Output to the lights is JB-04 (Terminal D). Between this and the TNS Relay, it goes through Connector X-11 again.
X-02 is the Fuse Box
X-11 is in the driver footwell, in the Kick Panel area below the Fuse box. It is the connector closest to the door. It connects the FRONT harness to the DASH harness.
JB-xx Connectors are on the back of the Joint Box (Inside fuse box)
Since X-11 is roughly level with the bottom of the Accelerator pedal, I would look there for corrosion first. Also, it may sound like a dumb idea, but you might want to try testing for continuity to Ground at the 3 affected fuses' input terminals. Between X-02 and X-11 AND X-11 to the Joint Box is the White/Red wire for Tail/Hazard/Stop fuses. With the Joint Box disconnected, the goal is to see if this wire has continuity to Ground with the Battery disconnected. One probe at JB-05 Terminal F, one to Chassis ground. It should be Infinite Ohms (no continuity). Note the meter reading here. Now disconnect Connector X-11 and see if it changes. If it jumps to infinite with X-11 unplugged, the bad part is between X-11 (Kick Panel connector) and X-02 (Fuse Box). If it does NOT change, the problem is between X-11 and JB-05.
It's been awhile since I saw one in person, but the Front Harness is routed in a loop in the Engine bay, behind the bodywork to help protect it from the turbos' heat. Start at the Firewall Grommet and follow it. Any iffy spots would likely be near the strut tower due to how close it is to the turbos.
EDIT:
So I did some digging and found this useful thread showing the physical layout of the Front Harness as one would see it on the car. It's for a LHD, but will get you in the ballpark Just imagine X-11 on the opposite side, close to X-05 and you'll get the idea.
https://www.norotors.com/index.php?topic=2468.0
Between the BTN Fuse and Tail Lamp Fuse are Connectors X-02, X-11 and JB-05 (Terminal F) again. Output to the lights is JB-04 (Terminal D). Between this and the TNS Relay, it goes through Connector X-11 again.
X-02 is the Fuse Box
X-11 is in the driver footwell, in the Kick Panel area below the Fuse box. It is the connector closest to the door. It connects the FRONT harness to the DASH harness.
JB-xx Connectors are on the back of the Joint Box (Inside fuse box)
Since X-11 is roughly level with the bottom of the Accelerator pedal, I would look there for corrosion first. Also, it may sound like a dumb idea, but you might want to try testing for continuity to Ground at the 3 affected fuses' input terminals. Between X-02 and X-11 AND X-11 to the Joint Box is the White/Red wire for Tail/Hazard/Stop fuses. With the Joint Box disconnected, the goal is to see if this wire has continuity to Ground with the Battery disconnected. One probe at JB-05 Terminal F, one to Chassis ground. It should be Infinite Ohms (no continuity). Note the meter reading here. Now disconnect Connector X-11 and see if it changes. If it jumps to infinite with X-11 unplugged, the bad part is between X-11 (Kick Panel connector) and X-02 (Fuse Box). If it does NOT change, the problem is between X-11 and JB-05.
It's been awhile since I saw one in person, but the Front Harness is routed in a loop in the Engine bay, behind the bodywork to help protect it from the turbos' heat. Start at the Firewall Grommet and follow it. Any iffy spots would likely be near the strut tower due to how close it is to the turbos.
EDIT:
So I did some digging and found this useful thread showing the physical layout of the Front Harness as one would see it on the car. It's for a LHD, but will get you in the ballpark Just imagine X-11 on the opposite side, close to X-05 and you'll get the idea.
https://www.norotors.com/index.php?topic=2468.0
it’s a little bit embarrassing writing this lol, but the confusion between the wiring diagram and the btn wire going into the chassis harness and not the dashboard was because I got 2 of the plugs mixed up 😅
everything is now working as it should! Have learnt a lot from you and I am very grateful for your help!
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Akagis_white_comet (11-28-21)
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