new rx7.. ? about tach output wire.
03-18-09 | 12:49 AM
#1
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From: reading,pa
new rx7.. ? about tach output wire.
alright my stock tach doesn't work.. I"m thinking its wiring because if my shift-up light still works then my tach should work too, right? so mabye my tach output wirre is bad or not connected? what ya guys think.... i took some pictures of some tach output wiring guestions i have.. Please help... I want my stock tach to work sooo bad and I dont wanna buy a new cluster if i dont have toooo and i dont wanna use an aftermarket tach becasue I just got the car last week. So i'm not looking to upgrade anything just yet. My pictures will have he questions inside them? can u guys please ansewer them for me?
thank you your new new rx7 owner Nick.
thank you your new new rx7 owner Nick.
03-18-09 | 03:42 PM
#4
HAILERS
Joined: May 2001
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From: FORT WORTH, TEXAS,USA
They are just what they are shown as in the online, free wiring diagrams. They are both spliced to eachother and are the INPUT wire to the tach in the instrument cluster.
Idle the engine. Pull one of the Trail sparkplug wires out of its bore a few milimeters. If you see spark, then the trail coil assy is working and your tach is not working for unknown reasons.
To prove the tach is bad or there is an open wire to it.........find a piece of electrical wire that will reach from the black bullet connector on the LEAD coil assy. Shove one end in that bullet connector and attach the other end of that wire to the Y/L wire in your jpg. Start then engine and see if the tach works or not. It should.
You might disconnect both white plugs to the trail coil assy before doing that for safety sake.
Or simply put a meter on the y/l wire while at idle. A meter with HZ(freq) and see if it shows the rpm or not.
Idle the engine. Pull one of the Trail sparkplug wires out of its bore a few milimeters. If you see spark, then the trail coil assy is working and your tach is not working for unknown reasons.
To prove the tach is bad or there is an open wire to it.........find a piece of electrical wire that will reach from the black bullet connector on the LEAD coil assy. Shove one end in that bullet connector and attach the other end of that wire to the Y/L wire in your jpg. Start then engine and see if the tach works or not. It should.
You might disconnect both white plugs to the trail coil assy before doing that for safety sake.
Or simply put a meter on the y/l wire while at idle. A meter with HZ(freq) and see if it shows the rpm or not.
03-18-09 | 03:59 PM
#5
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From: reading,pa
well i hooked up an aftermarket tach today and aftermarket tach it had power but tach rpm needle would not respond and i wired the signal wire to that yellow/blue wire that thats from my jpg.. and didn't work..... so my trail coil is bad? it wouldn't seem bad because my engine is fine and i don't have any miss-fires or anything. But I'm also new to rx7's... can u do me a flavor and show me an engine picture of what your talking about when you say this *find a piece of electrical wire that will reach from the black bullet connector on the LEAD coil assy. Shove one end in that bullet connector and attach the other end of that wire to the Y/L wire in your jpg. Start then engine and see if the tach works or not. It should*
can u do a engine picture of that for m please?... I don't know what a black bullet connecotr is.
can u do a engine picture of that for m please?... I don't know what a black bullet connecotr is.
03-18-09 | 05:06 PM
#6
HAILERS
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From: FORT WORTH, TEXAS,USA
Actually, if you put a meter on dc volts and attach it to the y/l wire, you'll see about a half volt dc at idle and if you rev it you'll see about 2.5 vdc.
If you want to know if the trail coil is working, pull one of the sparkplug wires out of the bore of the coil while the car is idling. It'll either be sparking or not.
If you want to know if the trail coil is working, pull one of the sparkplug wires out of the bore of the coil while the car is idling. It'll either be sparking or not.
03-18-09 | 05:09 PM
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03-18-09 | 07:05 PM
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From: reading,pa
Actually, if you put a meter on dc volts and attach it to the y/l wire, you'll see about a half volt dc at idle and if you rev it you'll see about 2.5 vdc.
If you want to know if the trail coil is working, pull one of the sparkplug wires out of the bore of the coil while the car is idling. It'll either be sparking or not.
If you want to know if the trail coil is working, pull one of the sparkplug wires out of the bore of the coil while the car is idling. It'll either be sparking or not.
03-18-09 | 09:59 PM
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From: reading,pa
03-19-09 | 07:20 PM
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From: reading,pa
Actually, if you put a meter on dc volts and attach it to the y/l wire, you'll see about a half volt dc at idle and if you rev it you'll see about 2.5 vdc.
If you want to know if the trail coil is working, pull one of the sparkplug wires out of the bore of the coil while the car is idling. It'll either be sparking or not.
If you want to know if the trail coil is working, pull one of the sparkplug wires out of the bore of the coil while the car is idling. It'll either be sparking or not.
so now what?
03-20-09 | 02:33 AM
#11
Mike Honcho
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From: des moines iowa
download the FSM in the stickies at the top of the section and follow the procedure for checking the coils, and pay attention to the wiring diagrams. also it would most likely do you good to not get impatient and threaten to leave the forum. the more you act like a jackass the more people will not want to help you out.
03-20-09 | 04:46 PM
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From: reading,pa
download the FSM in the stickies at the top of the section and follow the procedure for checking the coils, and pay attention to the wiring diagrams. also it would most likely do you good to not get impatient and threaten to leave the forum. the more you act like a jackass the more people will not want to help you out.
03-20-09 | 04:57 PM
#14
So, rather than actually teach yourself something, you're going to **** and moan that no one's going out of their way to spoon-feed you? Yeah...that's going to go over great. Might as well sell the car if you can't handle something as trivial as reading the manual.
03-20-09 | 10:49 PM
#16
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Well, mostly because the sections in the FSM you'd need aren't diagrams and have pictures and show you exactly what to do.
It's really actually pretty easy. Page 28 on the following link:
http://www.teamfc3s.org/main/factory...cal_System.pdf
It's really actually pretty easy. Page 28 on the following link:
http://www.teamfc3s.org/main/factory...cal_System.pdf
03-20-09 | 11:20 PM
#17
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From: reading,pa
Well, mostly because the sections in the FSM you'd need aren't diagrams and have pictures and show you exactly what to do.
It's really actually pretty easy. Page 28 on the following link:
http://www.teamfc3s.org/main/factory...cal_System.pdf
It's really actually pretty easy. Page 28 on the following link:
http://www.teamfc3s.org/main/factory...cal_System.pdf
03-20-09 | 11:24 PM
#18
Super Raterhater
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Read the actual page number ON the page you're reading, don't just scroll to page 28 in Acrobat or whatever you're using to view it. It'll say G-28 on it. (Although, I'm sure you'll now mention that the Leading is actually on page G-29, but technically, the coil section is 28!). Do the first portion here, (checking for power) Should be a black/yellow wire.
03-21-09 | 12:25 AM
#19
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Alright, I decided to be nice and make this idiot proof. Here's how this should work.
The two wire connector should have two Black/Yellow wires, each should give you +12V with key to ON. Ground your DMM and put the + lead onto each of those and verify you've got voltage @ the coils first.
If that works, reconnect the 2 wire connector and look at the 4 wire. The 4 wires are as follows:
Color - S5 ECU PIN - S4 ECU PIN - Checking procedures
Brown/Yellow - 1J - 1U - 4.4V with Ign. ON, about 2.2V @ idle
Blue/Yellow - 1G - 1X - 0V Ign On, .8V @ idle
Blue/Red (S5's are Green) - 1V - 1M - Below 2V with Ign. ON and @ idle (S5's should see 4V)
Yellow/Blue - Goes to Tach/Check connector
However, judging by your pictures it looks like someone at one point cut the yellow/blue (As you point to in the picture that says 'this is also yellow/blue') because it appears theres electrical tape on that wire right after the connector itself. I would take this electric tape off and see if it's spliced into something. If that wire's not Y/B I'd follow it to see where it goes. If this is the case, chances are just splicing it back into the cut Y/B that's hanging there will fix your tach signal.
The two wire connector should have two Black/Yellow wires, each should give you +12V with key to ON. Ground your DMM and put the + lead onto each of those and verify you've got voltage @ the coils first.
If that works, reconnect the 2 wire connector and look at the 4 wire. The 4 wires are as follows:
Color - S5 ECU PIN - S4 ECU PIN - Checking procedures
Brown/Yellow - 1J - 1U - 4.4V with Ign. ON, about 2.2V @ idle
Blue/Yellow - 1G - 1X - 0V Ign On, .8V @ idle
Blue/Red (S5's are Green) - 1V - 1M - Below 2V with Ign. ON and @ idle (S5's should see 4V)
Yellow/Blue - Goes to Tach/Check connector
However, judging by your pictures it looks like someone at one point cut the yellow/blue (As you point to in the picture that says 'this is also yellow/blue') because it appears theres electrical tape on that wire right after the connector itself. I would take this electric tape off and see if it's spliced into something. If that wire's not Y/B I'd follow it to see where it goes. If this is the case, chances are just splicing it back into the cut Y/B that's hanging there will fix your tach signal.
03-21-09 | 09:00 AM
#20
HAILERS
Joined: May 2001
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From: FORT WORTH, TEXAS,USA
The engine will run/idle fine with the trail coil not working. But I'm not saying the trail coil should not be repaired/fixed.
Idle the car and pull one of the plug wires out of the coil. IF you see no spark when holding that wire just outside the coil bore, it isn't working.
The tach works off the trail coil and it's yellow/blue wire.
A black bullet connector is shown in the jpg attached. That one in the jpg is on the LEAD coil assy. The TRAIL coil assy has/had one just like it. But SOMEONE has taken it off the Trail coil assy.
If one jumpers a wire from the black bullet connector on the LEAD coil assy to the yellow/blue wire on the trail coil assy, then the tach will work even if the trail coil is toast. Doing this proves the TACH wiring is good/valid, and more or less proves the trail coils assy isn't workiing. But you could prove that just by pulling a wire out of the trail coil assy while idling. Five minutes to proof.
Both lead and trail coils have to be bolted down to the chassis for them to work. The ignitor in each gets its gnd from being bolted to the chassis.
Coils rarely fail. But the ignitor in the trail coil assy could be toast. Coils are check like the jpg attached.
Check out the wires to the trail coil assy as SonicRat mentioned.
I'm not all that sure that just because the shift up light works, that the trail coil assy is working. Both the trail and lead coils work off the G and NE signals from the CAS.
Trail coil assy's used cost twenty bucks. I've one I'll sell you for a hunderd and fifty plus shipping. Send money first.
Idle the car and pull one of the plug wires out of the coil. IF you see no spark when holding that wire just outside the coil bore, it isn't working.
The tach works off the trail coil and it's yellow/blue wire.
A black bullet connector is shown in the jpg attached. That one in the jpg is on the LEAD coil assy. The TRAIL coil assy has/had one just like it. But SOMEONE has taken it off the Trail coil assy.
If one jumpers a wire from the black bullet connector on the LEAD coil assy to the yellow/blue wire on the trail coil assy, then the tach will work even if the trail coil is toast. Doing this proves the TACH wiring is good/valid, and more or less proves the trail coils assy isn't workiing. But you could prove that just by pulling a wire out of the trail coil assy while idling. Five minutes to proof.
Both lead and trail coils have to be bolted down to the chassis for them to work. The ignitor in each gets its gnd from being bolted to the chassis.
Coils rarely fail. But the ignitor in the trail coil assy could be toast. Coils are check like the jpg attached.
Check out the wires to the trail coil assy as SonicRat mentioned.
I'm not all that sure that just because the shift up light works, that the trail coil assy is working. Both the trail and lead coils work off the G and NE signals from the CAS.
Trail coil assy's used cost twenty bucks. I've one I'll sell you for a hunderd and fifty plus shipping. Send money first.
03-21-09 | 09:06 AM
#21
HAILERS
Joined: May 2001
Posts: 20,563
Likes: 23
From: FORT WORTH, TEXAS,USA
The engine will run/idle fine with the trail coil not working. But I'm not saying the trail coil should not be repaired/fixed.
Idle the car and pull one of the plug wires out of the coil. IF you see no spark when holding that wire just outside the coil bore, it isn't working.
The tach works off the trail coil and it's yellow/blue wire.
A black bullet connector is shown in the jpg attached. That one in the jpg is on the LEAD coil assy. The TRAIL coil assy has/had one just like it. But SOMEONE has taken it off the Trail coil assy.
If one jumpers a wire from the black bullet connector on the LEAD coil assy to the yellow/blue wire on the trail coil assy, then the tach will work even if the trail coil is toast. Doing this proves the TACH wiring is good/valid, and more or less proves the trail coils assy isn't workiing. But you could prove that just by pulling a wire out of the trail coil assy while idling. Five minutes to proof.
Both lead and trail coils have to be bolted down to the chassis for them to work. The ignitor in each gets its gnd from being bolted to the chassis.
Coils rarely fail. But the ignitor in the trail coil assy could be toast. Coils are check like the jpg attached.
Check out the wires to the trail coil assy as SonicRat mentioned.
I'm not all that sure that just because the shift up light works, that the trail coil assy is working. Both the trail and lead coils work off the G and NE signals from the CAS.
Trail coil assy's used cost twenty bucks. I've one I'll sell you for a hunderd and fifty plus shipping. Send money first.
Idle the car and pull one of the plug wires out of the coil. IF you see no spark when holding that wire just outside the coil bore, it isn't working.
The tach works off the trail coil and it's yellow/blue wire.
A black bullet connector is shown in the jpg attached. That one in the jpg is on the LEAD coil assy. The TRAIL coil assy has/had one just like it. But SOMEONE has taken it off the Trail coil assy.
If one jumpers a wire from the black bullet connector on the LEAD coil assy to the yellow/blue wire on the trail coil assy, then the tach will work even if the trail coil is toast. Doing this proves the TACH wiring is good/valid, and more or less proves the trail coils assy isn't workiing. But you could prove that just by pulling a wire out of the trail coil assy while idling. Five minutes to proof.
Both lead and trail coils have to be bolted down to the chassis for them to work. The ignitor in each gets its gnd from being bolted to the chassis.
Coils rarely fail. But the ignitor in the trail coil assy could be toast. Coils are check like the jpg attached.
Check out the wires to the trail coil assy as SonicRat mentioned.
I'm not all that sure that just because the shift up light works, that the trail coil assy is working. Both the trail and lead coils work off the G and NE signals from the CAS.
Trail coil assy's used cost twenty bucks. I've one I'll sell you for a hunderd and fifty plus shipping. Send money first.
03-21-09 | 10:05 AM
#22
He's begging for help, yet being a total dick whenever someone doesn't give him the exact answer he wants. Plus demonstrating a total lack of desire to research and find the answer himself.
03-21-09 | 04:22 PM
#23
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From: reading,pa
ok thanks for those posts.
but today I unbolted the trail pack and lifted it up off the brackets and tach worked, as soon as I droped the trail coil pack back down onto the holding brackets, the tach shut off. so is this telling my yellow/blue wire is bad or something?
but today I unbolted the trail pack and lifted it up off the brackets and tach worked, as soon as I droped the trail coil pack back down onto the holding brackets, the tach shut off. so is this telling my yellow/blue wire is bad or something?
03-21-09 | 04:29 PM
#25
clean all the grounds to both coils and all other things in the engine bay. Below is a link to show you how to do this. This is what i did when i bought my car and the tach stated working instantly
http://www.aaroncake.net/RX-7/grounding.htm
http://www.aaroncake.net/RX-7/grounding.htm