Blowing Meter Fuse - Part 3 (The End)
01-04-07 | 12:09 AM
#1
Thread Starter
Joined: Jun 2004
Posts: 2,761
Likes: 393
From: Virginia Beach, VA
Blowing Meter Fuse - Part 3 (The End)
It is FINALLY over! This is the final part of my struggle in fixing a Blowing Meter Fuse. Threads below track its history.
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/blowing-meter-fuse-part-2-a-598415/ (Part 2)
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/blowing-meter-fuse-564005/ (Part 1)
Early in December I finally located the fault! After many resistance checks and the infusion of new blood to solve the problem, I opted to check for shorts using an ammeter. I used a Fluke Clamp meter that is able to check DC Amps. Armed with the car battery, DC light bulb (load), and some ghetto rigged wires (even jumper cables were used) I injected 1A into the suspect line.
The suspect:
B-2: Coolant Fan System - JB-04 Pin I to Ground = SHORT
This wire goes to each leg of the Coolant Fan Relays, the wire color is B/Y.
The Path:
The meter was placed at several points along the front side of the wiring harness and yielded some interesting results. Sample points on either side of the front support rail indicate 0A; along the front support rail the meter indicated 1A. A parasite branch from the front side was also tested and it read 1A. Since it was hard to see what that line was I referenced the component location from the wiring diagram. Turns out it was JC-2 (Ground Point 2 for the Cooling system). Sweet find!
Focus was then shifted to the relay branches. On all but 1 branch, the meter indicated 1A. The sole branch read 0A. The sleeve of each branch was cut back to the main harness point, exposing each wire of all branches (this was done in November as part of visual inspections). Each wire of each branch was tested for DC Amps. As luck be had, the first branch tested was the 0A branch. Only 2 of the 4 wires indicated 0A while 2 were 1A. The wires were B/Y and B. This branch happened to be Relay #3. The remaining lines were tested to remove all doubts that 1A was only flowing between the B/Y and B wires on Relay #3 branch.
Seeing the Light:
Having much relief and exhaustion @ 2:30am, a further inspection of the white connector revealed to be the problem. I passed a fluorescent light behind the connector and proved my suspicion: About 90% of all wiring problems lye within 1” of the connector. Well in this case it was the connector. The shadows of the pins were overlapped! Now I visually inspected each of these connectors before and what I saw was discarded as ‘acceptable’. Each connector had that conductive goop and it looked rather nasty – black, gritty, greasy looking and caked on. Moving it around didn’t reveal much and since all the connectors had that gunk on it, I only checked one really well (trying to clear most of it away) then moved on with my troubleshooting. After cutting the wire (accidentally broke it from the connector), the problem was resolved – No more current flow on the clamp meter!
Mopping up:
Okay, so now it’s close to 3am and I beat! I retired for the rest of the morning and thusly started looking for a replacement harness on the forum. Sure enough, someone was willing to part with that branch…BTW, give it up for Dan, aka 209FD! With a hectic work schedule and the holidays upon us, I was unable to piece my car back together again. I had some extra time to play over the New Years’ weekend. It was my goal to get her up and running once more. After working 12hrs/day I was able to piece humpty-dumpty back together again. On 1 Jan 07, she was ready…turned the key to ON and watched my instrument cluster come back to life! There was one snag, the Coolant level sensor alarm was buzzing.
She’s alive….ALIVE!
After some minor probing in the engine bay, I opted to yank out my instrument cluster…again. BTW, it is not necessary to pull the steering wheel when yanking out the cluster. It’s easier to put it back in too. Anyway, I had a suspicion that a connector was loose in the cluster to cause the horn to light off. All leads on the flex ribbon were cleaned with an eraser and I made sure each tab was bent towards the plug. The all connectors fit perfectly and the cluster was reinstalled. On 2 Jan 07 my baby cranked over for the first time in 6 months and roared with fiery passion!
Other tasks done:
Installed 3 Defi D-series gauges (Boost, Oil Pres, Water Temp) on FlyRx7s Tripod (http://members.aol.com/flyrx7/Rx7-Gauge-Pod.html) I had the gauges and pod for quite some time! Built custom wire harness to power them but still have to get the lighting rigged to the dimmer switch. Installed the R1 Lip and brake ducts, repaired the water temp sensor line (after it was broke during 2nd tear down). And all new Fan relays; they were replaced due to lack of confidence.
Special thanks to:
My friend Ray who helped infuse new blood in troubleshooting (especially at 2:30am), the clamp meter (which is the best $350 money can buy)!
209FD (Dan) for contributing a segment of his front wiring harness
Ray Crowe for the sweet deal on the R1 Lip & brake ducts along with the myriad of other parts that were needed for this project.
Everyone on the forum for lending some guidance and direction, not to mention the patience to read all this!
Happy New Year!
George
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/blowing-meter-fuse-part-2-a-598415/ (Part 2)
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/blowing-meter-fuse-564005/ (Part 1)
Early in December I finally located the fault! After many resistance checks and the infusion of new blood to solve the problem, I opted to check for shorts using an ammeter. I used a Fluke Clamp meter that is able to check DC Amps. Armed with the car battery, DC light bulb (load), and some ghetto rigged wires (even jumper cables were used) I injected 1A into the suspect line.
The suspect:
B-2: Coolant Fan System - JB-04 Pin I to Ground = SHORT
This wire goes to each leg of the Coolant Fan Relays, the wire color is B/Y.
The Path:
The meter was placed at several points along the front side of the wiring harness and yielded some interesting results. Sample points on either side of the front support rail indicate 0A; along the front support rail the meter indicated 1A. A parasite branch from the front side was also tested and it read 1A. Since it was hard to see what that line was I referenced the component location from the wiring diagram. Turns out it was JC-2 (Ground Point 2 for the Cooling system). Sweet find!
Focus was then shifted to the relay branches. On all but 1 branch, the meter indicated 1A. The sole branch read 0A. The sleeve of each branch was cut back to the main harness point, exposing each wire of all branches (this was done in November as part of visual inspections). Each wire of each branch was tested for DC Amps. As luck be had, the first branch tested was the 0A branch. Only 2 of the 4 wires indicated 0A while 2 were 1A. The wires were B/Y and B. This branch happened to be Relay #3. The remaining lines were tested to remove all doubts that 1A was only flowing between the B/Y and B wires on Relay #3 branch.
Seeing the Light:
Having much relief and exhaustion @ 2:30am, a further inspection of the white connector revealed to be the problem. I passed a fluorescent light behind the connector and proved my suspicion: About 90% of all wiring problems lye within 1” of the connector. Well in this case it was the connector. The shadows of the pins were overlapped! Now I visually inspected each of these connectors before and what I saw was discarded as ‘acceptable’. Each connector had that conductive goop and it looked rather nasty – black, gritty, greasy looking and caked on. Moving it around didn’t reveal much and since all the connectors had that gunk on it, I only checked one really well (trying to clear most of it away) then moved on with my troubleshooting. After cutting the wire (accidentally broke it from the connector), the problem was resolved – No more current flow on the clamp meter!
Mopping up:
Okay, so now it’s close to 3am and I beat! I retired for the rest of the morning and thusly started looking for a replacement harness on the forum. Sure enough, someone was willing to part with that branch…BTW, give it up for Dan, aka 209FD! With a hectic work schedule and the holidays upon us, I was unable to piece my car back together again. I had some extra time to play over the New Years’ weekend. It was my goal to get her up and running once more. After working 12hrs/day I was able to piece humpty-dumpty back together again. On 1 Jan 07, she was ready…turned the key to ON and watched my instrument cluster come back to life! There was one snag, the Coolant level sensor alarm was buzzing.
She’s alive….ALIVE!
After some minor probing in the engine bay, I opted to yank out my instrument cluster…again. BTW, it is not necessary to pull the steering wheel when yanking out the cluster. It’s easier to put it back in too. Anyway, I had a suspicion that a connector was loose in the cluster to cause the horn to light off. All leads on the flex ribbon were cleaned with an eraser and I made sure each tab was bent towards the plug. The all connectors fit perfectly and the cluster was reinstalled. On 2 Jan 07 my baby cranked over for the first time in 6 months and roared with fiery passion!
Other tasks done:
Installed 3 Defi D-series gauges (Boost, Oil Pres, Water Temp) on FlyRx7s Tripod (http://members.aol.com/flyrx7/Rx7-Gauge-Pod.html) I had the gauges and pod for quite some time! Built custom wire harness to power them but still have to get the lighting rigged to the dimmer switch. Installed the R1 Lip and brake ducts, repaired the water temp sensor line (after it was broke during 2nd tear down). And all new Fan relays; they were replaced due to lack of confidence.
Special thanks to:
My friend Ray who helped infuse new blood in troubleshooting (especially at 2:30am), the clamp meter (which is the best $350 money can buy)!
209FD (Dan) for contributing a segment of his front wiring harness
Ray Crowe for the sweet deal on the R1 Lip & brake ducts along with the myriad of other parts that were needed for this project.
Everyone on the forum for lending some guidance and direction, not to mention the patience to read all this!
Happy New Year!
George
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gracer7-rx7 (01-18-23)
07-12-11 | 12:53 PM
#3
Thread Starter
Joined: Jun 2004
Posts: 2,761
Likes: 393
From: Virginia Beach, VA
sorry, no pictures. Take a look at the schematic along with the three threads I attached. Do a good visiual inspection of all connectors before reading out wires. Always remember that 99% of all electrical problems happen within 1" of a connector. If possible, shine a light behind a connector to see if any contacts are touching (works with white or clear connectors only).
01-15-23 | 04:53 PM
#4
Newbie
Joined: Jan 2023
Posts: 4
Likes: 0
From: chicago
Connector?
It is FINALLY over! This is the final part of my struggle in fixing a Blowing Meter Fuse. Threads below track its history.
https://www.rx7club.com/showthread.php?t=598415 (Part 2)
https://www.rx7club.com/showthread.php?t=564005 (Part 1)
Early in December I finally located the fault! After many resistance checks and the infusion of new blood to solve the problem, I opted to check for shorts using an ammeter. I used a Fluke Clamp meter that is able to check DC Amps. Armed with the car battery, DC light bulb (load), and some ghetto rigged wires (even jumper cables were used) I injected 1A into the suspect line.
The suspect:
B-2: Coolant Fan System - JB-04 Pin I to Ground = SHORT
This wire goes to each leg of the Coolant Fan Relays, the wire color is B/Y.
The Path:
The meter was placed at several points along the front side of the wiring harness and yielded some interesting results. Sample points on either side of the front support rail indicate 0A; along the front support rail the meter indicated 1A. A parasite branch from the front side was also tested and it read 1A. Since it was hard to see what that line was I referenced the component location from the wiring diagram. Turns out it was JC-2 (Ground Point 2 for the Cooling system). Sweet find!
Focus was then shifted to the relay branches. On all but 1 branch, the meter indicated 1A. The sole branch read 0A. The sleeve of each branch was cut back to the main harness point, exposing each wire of all branches (this was done in November as part of visual inspections). Each wire of each branch was tested for DC Amps. As luck be had, the first branch tested was the 0A branch. Only 2 of the 4 wires indicated 0A while 2 were 1A. The wires were B/Y and B. This branch happened to be Relay #3. The remaining lines were tested to remove all doubts that 1A was only flowing between the B/Y and B wires on Relay #3 branch.
Seeing the Light:
Having much relief and exhaustion @ 2:30am, a further inspection of the white connector revealed to be the problem. I passed a fluorescent light behind the connector and proved my suspicion: About 90% of all wiring problems lye within 1” of the connector. Well in this case it was the connector. The shadows of the pins were overlapped! Now I visually inspected each of these connectors before and what I saw was discarded as ‘acceptable’. Each connector had that conductive goop and it looked rather nasty – black, gritty, greasy looking and caked on. Moving it around didn’t reveal much and since all the connectors had that gunk on it, I only checked one really well (trying to clear most of it away) then moved on with my troubleshooting. After cutting the wire (accidentally broke it from the connector), the problem was resolved – No more current flow on the clamp meter!
Mopping up:
Okay, so now it’s close to 3am and I beat! I retired for the rest of the morning and thusly started looking for a replacement harness on the forum. Sure enough, someone was willing to part with that branch…BTW, give it up for Dan, aka 209FD! With a hectic work schedule and the holidays upon us, I was unable to piece my car back together again. I had some extra time to play over the New Years’ weekend. It was my goal to get her up and running once more. After working 12hrs/day I was able to piece humpty-dumpty back together again. On 1 Jan 07, she was ready…turned the key to ON and watched my instrument cluster come back to life! There was one snag, the Coolant level sensor alarm was buzzing.
She’s alive….ALIVE!
After some minor probing in the engine bay, I opted to yank out my instrument cluster…again. BTW, it is not necessary to pull the steering wheel when yanking out the cluster. It’s easier to put it back in too. Anyway, I had a suspicion that a connector was loose in the cluster to cause the horn to light off. All leads on the flex ribbon were cleaned with an eraser and I made sure each tab was bent towards the plug. The all connectors fit perfectly and the cluster was reinstalled. On 2 Jan 07 my baby cranked over for the first time in 6 months and roared with fiery passion!
Other tasks done:
Installed 3 Defi D-series gauges (Boost, Oil Pres, Water Temp) on FlyRx7s Tripod (http://members.aol.com/flyrx7/Rx7-Gauge-Pod.html) I had the gauges and pod for quite some time! Built custom wire harness to power them but still have to get the lighting rigged to the dimmer switch. Installed the R1 Lip and brake ducts, repaired the water temp sensor line (after it was broke during 2nd tear down). And all new Fan relays; they were replaced due to lack of confidence.
Special thanks to:
My friend Ray who helped infuse new blood in troubleshooting (especially at 2:30am), the clamp meter (which is the best $350 money can buy)!
209FD (Dan) for contributing a segment of his front wiring harness
Ray Crowe for the sweet deal on the R1 Lip & brake ducts along with the myriad of other parts that were needed for this project.
Everyone on the forum for lending some guidance and direction, not to mention the patience to read all this!
Happy New Year!
George
https://www.rx7club.com/showthread.php?t=598415 (Part 2)
https://www.rx7club.com/showthread.php?t=564005 (Part 1)
Early in December I finally located the fault! After many resistance checks and the infusion of new blood to solve the problem, I opted to check for shorts using an ammeter. I used a Fluke Clamp meter that is able to check DC Amps. Armed with the car battery, DC light bulb (load), and some ghetto rigged wires (even jumper cables were used) I injected 1A into the suspect line.
The suspect:
B-2: Coolant Fan System - JB-04 Pin I to Ground = SHORT
This wire goes to each leg of the Coolant Fan Relays, the wire color is B/Y.
The Path:
The meter was placed at several points along the front side of the wiring harness and yielded some interesting results. Sample points on either side of the front support rail indicate 0A; along the front support rail the meter indicated 1A. A parasite branch from the front side was also tested and it read 1A. Since it was hard to see what that line was I referenced the component location from the wiring diagram. Turns out it was JC-2 (Ground Point 2 for the Cooling system). Sweet find!
Focus was then shifted to the relay branches. On all but 1 branch, the meter indicated 1A. The sole branch read 0A. The sleeve of each branch was cut back to the main harness point, exposing each wire of all branches (this was done in November as part of visual inspections). Each wire of each branch was tested for DC Amps. As luck be had, the first branch tested was the 0A branch. Only 2 of the 4 wires indicated 0A while 2 were 1A. The wires were B/Y and B. This branch happened to be Relay #3. The remaining lines were tested to remove all doubts that 1A was only flowing between the B/Y and B wires on Relay #3 branch.
Seeing the Light:
Having much relief and exhaustion @ 2:30am, a further inspection of the white connector revealed to be the problem. I passed a fluorescent light behind the connector and proved my suspicion: About 90% of all wiring problems lye within 1” of the connector. Well in this case it was the connector. The shadows of the pins were overlapped! Now I visually inspected each of these connectors before and what I saw was discarded as ‘acceptable’. Each connector had that conductive goop and it looked rather nasty – black, gritty, greasy looking and caked on. Moving it around didn’t reveal much and since all the connectors had that gunk on it, I only checked one really well (trying to clear most of it away) then moved on with my troubleshooting. After cutting the wire (accidentally broke it from the connector), the problem was resolved – No more current flow on the clamp meter!
Mopping up:
Okay, so now it’s close to 3am and I beat! I retired for the rest of the morning and thusly started looking for a replacement harness on the forum. Sure enough, someone was willing to part with that branch…BTW, give it up for Dan, aka 209FD! With a hectic work schedule and the holidays upon us, I was unable to piece my car back together again. I had some extra time to play over the New Years’ weekend. It was my goal to get her up and running once more. After working 12hrs/day I was able to piece humpty-dumpty back together again. On 1 Jan 07, she was ready…turned the key to ON and watched my instrument cluster come back to life! There was one snag, the Coolant level sensor alarm was buzzing.
She’s alive….ALIVE!
After some minor probing in the engine bay, I opted to yank out my instrument cluster…again. BTW, it is not necessary to pull the steering wheel when yanking out the cluster. It’s easier to put it back in too. Anyway, I had a suspicion that a connector was loose in the cluster to cause the horn to light off. All leads on the flex ribbon were cleaned with an eraser and I made sure each tab was bent towards the plug. The all connectors fit perfectly and the cluster was reinstalled. On 2 Jan 07 my baby cranked over for the first time in 6 months and roared with fiery passion!
Other tasks done:
Installed 3 Defi D-series gauges (Boost, Oil Pres, Water Temp) on FlyRx7s Tripod (http://members.aol.com/flyrx7/Rx7-Gauge-Pod.html) I had the gauges and pod for quite some time! Built custom wire harness to power them but still have to get the lighting rigged to the dimmer switch. Installed the R1 Lip and brake ducts, repaired the water temp sensor line (after it was broke during 2nd tear down). And all new Fan relays; they were replaced due to lack of confidence.
Special thanks to:
My friend Ray who helped infuse new blood in troubleshooting (especially at 2:30am), the clamp meter (which is the best $350 money can buy)!
209FD (Dan) for contributing a segment of his front wiring harness
Ray Crowe for the sweet deal on the R1 Lip & brake ducts along with the myriad of other parts that were needed for this project.
Everyone on the forum for lending some guidance and direction, not to mention the patience to read all this!
Happy New Year!
George
the one next to the fuses on the kick panel?
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