A clutch job, the wiring harness, and the METER fuse
02-13-12, 08:26 PM
#1
RX-7 Bad Ass
Thread Starter
iTrader: (55)
A clutch job, the wiring harness, and the METER fuse
Hey guys -
Just wanted to document this as a cautionary tale, hopefully this will help someone else down the road. And, you get to have a chuckle at Mr. RX-7 Guru making a boo-boo
.
Helped a buddy put a new clutch and light flywheel in his FD this weekend. Clutch was TOTALLY gone, car wouldn't even move it was worn so thin. Put a nice new Exedy clutch kit on ($225 from Amazon!), a low-mileage chromoly light flywheel ($150 off Ebay), and a midpipe.
Clutch job generally went well, once all was said and done the car ran great, revved nice with the new flywheel, happy days. Minor problem - the gauges weren't working. Weird, but we were wore the heck out and called it a day.
Tonight I went to go take a look at the car. Symptoms -
- Turn signals would not work, but hazards would work.
- Only the fuel gauge worked, all the other gauges (tach, speedo, odometer, oil pressure, water temp) didn't work. Idiot lights didn't work either.
- Fans wouldn't run when the car got up to fan temp.
- Reverse lights wouldn't work
Went into the Sensor Check screen on the PowerFC, noticed the neutral switch didn't work and the reverse switch didn't work. Hmmm.
Tested ALL the fuses - by this, I mean pull the fuse, test continuity with a multimeter, reinstall. Found the METER fuse was blown, this is a 15 amp fuse in the small fuse block by the clutch pedal.
OK, popped another one in, still the same symptoms. It was a used fuse I had, so I figured maybe it was just a bad one, got a new one, turned the key, saw the idiot lights come on for an INSTANT then go out. New fuse was blown.
Looked under the hood behind the intake manifold. Sure enough, the thin wiring harness going to the transmission from the ECU harness got pinched betweeen the transmission and the engine. Wires are shorting out, blowing the fuse.
So, coming up soon I'll be unplugging the trans harness from the transmission, unbolting the transmission enough to pull it back a little from the engine to get the harness out, then going through and repairing the damage.
I had NO idea that so much stuff was on the METER fuse circuit. The biggie here is the fans - you can really do some engine damage if you don't watch out!
I think the new protocol for doing a clutch job for me will be pulling the harness up and putting it on top of the intake manifold until the trans is in. A little bit of extra work could have prevented this problem to start with.
Dale
Just wanted to document this as a cautionary tale, hopefully this will help someone else down the road. And, you get to have a chuckle at Mr. RX-7 Guru making a boo-boo
.Helped a buddy put a new clutch and light flywheel in his FD this weekend. Clutch was TOTALLY gone, car wouldn't even move it was worn so thin. Put a nice new Exedy clutch kit on ($225 from Amazon!), a low-mileage chromoly light flywheel ($150 off Ebay), and a midpipe.
Clutch job generally went well, once all was said and done the car ran great, revved nice with the new flywheel, happy days. Minor problem - the gauges weren't working. Weird, but we were wore the heck out and called it a day.
Tonight I went to go take a look at the car. Symptoms -
- Turn signals would not work, but hazards would work.
- Only the fuel gauge worked, all the other gauges (tach, speedo, odometer, oil pressure, water temp) didn't work. Idiot lights didn't work either.
- Fans wouldn't run when the car got up to fan temp.
- Reverse lights wouldn't work
Went into the Sensor Check screen on the PowerFC, noticed the neutral switch didn't work and the reverse switch didn't work. Hmmm.
Tested ALL the fuses - by this, I mean pull the fuse, test continuity with a multimeter, reinstall. Found the METER fuse was blown, this is a 15 amp fuse in the small fuse block by the clutch pedal.
OK, popped another one in, still the same symptoms. It was a used fuse I had, so I figured maybe it was just a bad one, got a new one, turned the key, saw the idiot lights come on for an INSTANT then go out. New fuse was blown.
Looked under the hood behind the intake manifold. Sure enough, the thin wiring harness going to the transmission from the ECU harness got pinched betweeen the transmission and the engine. Wires are shorting out, blowing the fuse.
So, coming up soon I'll be unplugging the trans harness from the transmission, unbolting the transmission enough to pull it back a little from the engine to get the harness out, then going through and repairing the damage.
I had NO idea that so much stuff was on the METER fuse circuit. The biggie here is the fans - you can really do some engine damage if you don't watch out!
I think the new protocol for doing a clutch job for me will be pulling the harness up and putting it on top of the intake manifold until the trans is in. A little bit of extra work could have prevented this problem to start with.
Dale
02-13-12, 09:02 PM
#2
Original Gangster/Rotary!
iTrader: (213)
Good thread Dale..... I've always been careful to keep the trans extention harness with those four connectors on it out of the way when doing a trans or clutch job.
One other thing for people installing aftermarket clutches with stiffer pressure plates: It's a good idea to replace your original clutch fork with the newer stouter unit available from Mazda
One other thing for people installing aftermarket clutches with stiffer pressure plates: It's a good idea to replace your original clutch fork with the newer stouter unit available from Mazda
02-13-12, 09:04 PM
#3
shame, shame on you!! lol We'v all been there in some way or another. Just tack it up to too much beer. Glad you found the problem.
Agreed. I did just that when changing out my clutch. I wasn't sure if it was replace by the previous owner--now I know it is!
Agreed. I did just that when changing out my clutch. I wasn't sure if it was replace by the previous owner--now I know it is!
02-19-12, 07:44 PM
#4
RX-7 Bad Ass
Thread Starter
iTrader: (55)
We fixed the problem this weekend. Some notes in case you have to do this -
- Get the car up in the air, remove the starter, clutch slave cylinder, and all the transmission bolts. I put one of the bolts back in and hand tightened it down until it was about 1/4" from touching, just to make sure the transmission didn't come all the way out. Doubt that it could, but I wanted to be sure.
- I went ahead and removed the upper intake manifold to have enough room to work. MAKE SURE to cover the ports to the lower intake manifold, when you pull the harness up there will be crispy bits of plastic and tape about and it could easily fall in the engine.
- There is an inspection plate between the engine and the transmission held on with 1 12mm bolt. Remove that plate, that gives some more room and the harness was pinched on that plate as well.
- Unplug the wiring from the transmission and pull the harness up over the engine.
- Get a prybar between the engine and transmission up top and pull back just enough to get the harness out. You won't be able to get much movement on it, we had to work just to get a bit to pull the harness out.
- Once the harness is free, remove any damaged old tape around the area and examine all the wires CAREFULLY. We cut through 3 wires and had another 2 damaged to where the insulation was gone and bare wire was showing. The bare wire ones we wrapped in tape, then used butt crimp connectors to fix the 3 cut wires. Wrapped all that area back up in good tape.
- Snake the harness back down and plug into the transmission. Replace the METER fuse and test that the gauges come on, turn signals work, reverse lights work, etc. If so, button back up.
Took most of a morning to do, wasn't too bad. Also didn't help that it was raining so we did it in my smallish garage.
Everything's hunky dory with the car now.
Dale
- Get the car up in the air, remove the starter, clutch slave cylinder, and all the transmission bolts. I put one of the bolts back in and hand tightened it down until it was about 1/4" from touching, just to make sure the transmission didn't come all the way out. Doubt that it could, but I wanted to be sure.
- I went ahead and removed the upper intake manifold to have enough room to work. MAKE SURE to cover the ports to the lower intake manifold, when you pull the harness up there will be crispy bits of plastic and tape about and it could easily fall in the engine.
- There is an inspection plate between the engine and the transmission held on with 1 12mm bolt. Remove that plate, that gives some more room and the harness was pinched on that plate as well.
- Unplug the wiring from the transmission and pull the harness up over the engine.
- Get a prybar between the engine and transmission up top and pull back just enough to get the harness out. You won't be able to get much movement on it, we had to work just to get a bit to pull the harness out.
- Once the harness is free, remove any damaged old tape around the area and examine all the wires CAREFULLY. We cut through 3 wires and had another 2 damaged to where the insulation was gone and bare wire was showing. The bare wire ones we wrapped in tape, then used butt crimp connectors to fix the 3 cut wires. Wrapped all that area back up in good tape.
- Snake the harness back down and plug into the transmission. Replace the METER fuse and test that the gauges come on, turn signals work, reverse lights work, etc. If so, button back up.
Took most of a morning to do, wasn't too bad. Also didn't help that it was raining so we did it in my smallish garage.
Everything's hunky dory with the car now.
Dale
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