98 Civic 5MT, no reverse lights after transmission overhaul
#1
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
98 Civic 5MT, no reverse lights after transmission overhaul
Spent 10 hours under my car yesterday getting it ready for inspection, and I can't figure out why my reverse lights aren't working. A few months ago, I finally completed a transmission overhaul. I assume my reverse lights worked before the overhaul, but I can't say for sure that they did.
After reinstalling the transmission, discovered that the plug going to the reverse sensor on the transmission magically didn't have enough wire to reach. I tugged, pulled, and traced the wire, and it isn't pinched or caught on anything, so I have no clue where the missing length of wire ran off to.
Started off by replacing both bulbs, still no light. Old and new bulbs both appear to be in perfect condition.
Decided to create my own extension harness. Easy enough, it's only two wires. Cut two pieces to the needed length, patched those wires into the sensor wire, crimped and heat shrank connections, added some shrouding to keep it all safe, and e-taped it all. Looks great, but still no reverse lights.
ALL other lights now work, including all interior lights. Is it possible that the reverse sensor was damaged in the overhaul? How can I test it? If the sensor isn't damaged, how should I go about figuring out why the lights aren't working? Worst case scenario, how can I go about wiring in a manual switch to toggle the reverse lights? I need to get the car inspected like, yesterday, and my inspector already told me that a manual switch would pass, and it would be a lot easier than sourcing a reverse switch, waiting for delivery, and installing it. In his words, "As long as the lights work, I don't give a damn how they work."
After reinstalling the transmission, discovered that the plug going to the reverse sensor on the transmission magically didn't have enough wire to reach. I tugged, pulled, and traced the wire, and it isn't pinched or caught on anything, so I have no clue where the missing length of wire ran off to.
Started off by replacing both bulbs, still no light. Old and new bulbs both appear to be in perfect condition.
Decided to create my own extension harness. Easy enough, it's only two wires. Cut two pieces to the needed length, patched those wires into the sensor wire, crimped and heat shrank connections, added some shrouding to keep it all safe, and e-taped it all. Looks great, but still no reverse lights.
ALL other lights now work, including all interior lights. Is it possible that the reverse sensor was damaged in the overhaul? How can I test it? If the sensor isn't damaged, how should I go about figuring out why the lights aren't working? Worst case scenario, how can I go about wiring in a manual switch to toggle the reverse lights? I need to get the car inspected like, yesterday, and my inspector already told me that a manual switch would pass, and it would be a lot easier than sourcing a reverse switch, waiting for delivery, and installing it. In his words, "As long as the lights work, I don't give a damn how they work."
#2
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
Is 7.5A dash fuse 19 blown?
If you unplug the switch and turn the key to ON(II), do either of the two terminals in the plug have voltage to body ground?
If you unplug the switch and turn the key to ON(II), do either of the two terminals in the plug have voltage to body ground?
#4
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
edit: You said 19, and I checked 17 like an idiot. Double checking now.
edit again: Checked 19, swapped with known working, still nothing.
Swapped in a new fuse and new bulbs, still nothing.
#5
#6
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
Tested the reverse switch plug. On the harness side, 6V on the yellow/silver wire. On the plug side, nothing. Also went ahead and ohm tested fuse 19, as well as both reverse bulbs. All passed.
I'm starting to think the reverse sensor is dead. Unless there's something else I should test first, my next plan is to remove the sensor and see if the reverse lights come on when I press it manually.
I'm starting to think the reverse sensor is dead. Unless there's something else I should test first, my next plan is to remove the sensor and see if the reverse lights come on when I press it manually.
#7
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
One terminal on the harness side should have battery voltage (~12.5V).
What voltage do you read on each top test tab of fuse 19?
What voltage do you read on each top test tab of fuse 19?
Trending Topics
#9
#11
#12
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
I tested it with the fuse removed, so I assumed only one lead should have power. Should I have tested with the fuse installed? The three fuses I've gone though passed an Ohm test while removed.
#13
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
Install the fuse and measure voltage at each top test tab. What are the readings?
If both top test tabs have battery voltage, the next voltage test is done on pin 15 on the male-side of connector C131:
If both top test tabs have battery voltage, the next voltage test is done on pin 15 on the male-side of connector C131:
Last edited by Former User; 08-06-2012 at 07:21 PM.
#14
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
12.3V on both tabs with the fuse installed. Sorry it took me so long to get back to this thread. Weather and work schedules have been liberally shitting on me.
Is this C131? Where exactly can I find it under the passenger side kick panel?
Is this C131? Where exactly can I find it under the passenger side kick panel?
#15
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
It's a green connector in front of the ECU. The pin and wire color pattern will match the diagram above.
The ECU is located behind the ABS control unit in the photo below.
The ECU is located behind the ABS control unit in the photo below.
Last edited by Former User; 08-13-2012 at 08:24 AM.
#16
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
OK, I don't have ABS, but I know the connector you're talking about. I'll poke at it with a multimeter as soon as time permits.
#17
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
12.02V on both ends of the connector at wire. Confirmed yellow/red on one end, yellow/silver on the other. 12.11 across the battery terminal, for reference. Voltage didn't change regardless of neutral/reverse.
Where should I check next?
Where should I check next?
Last edited by jbpnoman; 08-17-2012 at 03:43 AM.
#18
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
Next step:
Reconnect the plug, turn key to ON(II), and again measure voltage at the Yel wire of the reverse light switch plug. What's the voltage?
#19
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
I back probed on both sides, and unplugged it. Got the same reading on all three tests, .01v tolerance.
Post #6, I mentioned I only had 6v on the yellow wire on the reverse switch. I'll go double check it now while I'm replacing my brake booster.
Post #6, I mentioned I only had 6v on the yellow wire on the reverse switch. I'll go double check it now while I'm replacing my brake booster.
#20
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
When C131 is unplugged, the male-side connector terminal (Yel/Red wire) should have voltage whereas the female side terminal (Yel wire) should not.
At this point, it's important to verify the original voltage test at the female side (Yel wire) of the switch connector.
Post #6, I mentioned I only had 6v on the yellow wire on the reverse switch. I'll go double check it now while I'm replacing my brake booster.
#21
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
Yep, going to test that now. Yellow wire, female side.
#22
B*a*n*n*e*d
Thread Starter
Join Date: Feb 2008
Location: Charlottesville, VA, USA
Posts: 6,420
Likes: 0
Received 5 Likes
on
5 Posts
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
11.97v at the yellow wire, female side.
Thanks for helping me work through this, RonJ. Hopefully we can get it figured out.
Thanks for helping me work through this, RonJ. Hopefully we can get it figured out.
#25
Re: 98 Civic 5MT, no reverse lights after transmission overhaul
your pin on your reverve harness might be damaged/bent. when you put the shifter into reverse, the transmission presses on a pin that sends the signal to your back lights. this could have been damaged by you/the mechanic when the transmission was off the car, laying on the ground. double check that.