Changed spark plug leads, now blowing 15A engine fuse

soldave · 06-27-2010, 04:42 AM

A bit of a strange one here. A few days ago I changed my spark plug leads to some RE Ameniya ones as my current ones have been on almost 19 years I think and their resistance was way higher than what they should be. Anyway, I turn the key and the engine fires for a second and then dies. I think it's flooded so check the wiring and pull the plugs but no fuel and all seems well. But it still won't fire.

I did some troubleshooting and found that my 15A engine fuse was blown. So I replaced it and rechecked the plug wires to make sure they were fully connected but it blew straight away, even with the key just put to the "on" position (not even starting). I started to wonder if it was some of the wiring in my fuel pump rewire modification that I'd done so I pulled the 15A fuse going from the battery to my new fuel pump relay to check, but as soon as the key goes to the "on" position the 15A engine fuse will keep blowing.

Have no idea what I could have done that would cause this fuse to suddenly keep blowing; could I have knocked something near the ignition coils when I was replacing the leads? Any thoughts on the problem and how to solve it would be greatly appreciated

***TitaniumTT*** · 06-27-2010, 08:15 AM

If it's one of the main fuses on the shock tower, it should be a 30A fuse

soldave · 06-27-2010, 08:26 AM

It's not. It's the 15A engine fuse in the fuse box next to the gas pedal

soldave · 06-28-2010, 06:58 AM

OK, progress report time.

Pulled the 2-wire plug out of the main relay and turned ignition on - fuse blows
Pulled the connector out of circuit opening relay and turned ignition on, fuse doesn't blow. Turn key and engine almost fires but then dies.

Tested circuit opening relay and all the voltages & resistances came back ok. I then look at what the circuit opening relay does again, and go to the back to check my fuel pump relay I rigged up. One wire (blue and something) was loose so I reconnected it and put the connector back onto circuit opening relay. When ignition goes to "on" it's fine, but when it goes to "Start" it blows again. Then tried putting ignition to "on" and then connecting the fuel pump diagnostic switch (the yellow one in the engine bay). Sure enough, as soon as I connected it, the fuse blew.

So it looks like my fabulous mechanical skills have failed somewhere again. Am going to have to check and probably redo all the wiring going to the pump and maybe get a new relay too

NoDOHC · 06-28-2010, 09:54 PM

Sounds like your mechanical skills are just fine... and I would venture to guess that your electrical skills are improving very rapidly.

Don't forget that most people wouldn't even know what you are talking about, let alone attempt it themselves.

The best way to learn is to try.

***TitaniumTT*** · 06-28-2010, 10:52 PM

pull the fuel pump connector out and insert an LED or something very low draw and see what happens. Test the voltages and test for shorts.

I've seen shit like that drive people insane for hours upon hours and the problem was a trim screw pierced a wire when some random piece of trim went back on.

it would help if posted a schematic of EXACTELY how you wired this thing up.

soldave · 06-29-2010, 12:54 AM

Pulled the blue wire and blew a fuse again when I turned the key, but thinking about relays got me thinking about the eliminated resistor relay at the front. Pulled the air filter out of the way and found some of the insulation tape I had on one of the soldered connections had come off, and typically it was resting on a grounding point. Insulated it again, reconnected the blue wire and turned the key. Engine fire up first time. Bingo.

Another problem solved. Many, many more to go!

vex · 06-29-2010, 08:42 AM

Solution: Don't use insulation tape to keep wires from grounding out. Use heat shrink, or run an entire new wire.

soldave · 06-29-2010, 08:43 AM

Heat shrink not as easy to come across here in Okinawa as you'd think.

06-27-2010, 04:42 AM	#1
soldave Rotary Fanatic Join Date: Jun 2010 Location: Okinawa, Japan iTrader: (0) Posts: 134 Rep Power: 15	Changed spark plug leads, now blowing 15A engine fuse A bit of a strange one here. A few days ago I changed my spark plug leads to some RE Ameniya ones as my current ones have been on almost 19 years I think and their resistance was way higher than what they should be. Anyway, I turn the key and the engine fires for a second and then dies. I think it's flooded so check the wiring and pull the plugs but no fuel and all seems well. But it still won't fire. I did some troubleshooting and found that my 15A engine fuse was blown. So I replaced it and rechecked the plug wires to make sure they were fully connected but it blew straight away, even with the key just put to the "on" position (not even starting). I started to wonder if it was some of the wiring in my fuel pump rewire modification that I'd done so I pulled the 15A fuse going from the battery to my new fuel pump relay to check, but as soon as the key goes to the "on" position the 15A engine fuse will keep blowing. Have no idea what I could have done that would cause this fuse to suddenly keep blowing; could I have knocked something near the ignition coils when I was replacing the leads? Any thoughts on the problem and how to solve it would be greatly appreciated

06-27-2010, 08:15 AM	#2
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	If it's one of the main fuses on the shock tower, it should be a 30A fuse __________________ -The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. *-Angry Motherfcker Mode ENGAGED-**

06-28-2010, 09:54 PM	#5
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin iTrader: (1) Posts: 855 Rep Power: 17	Sounds like your mechanical skills are just fine... and I would venture to guess that your electrical skills are improving very rapidly. Don't forget that most people wouldn't even know what you are talking about, let alone attempt it themselves. The best way to learn is to try. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

06-28-2010, 10:52 PM	#6
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	pull the fuel pump connector out and insert an LED or something very low draw and see what happens. Test the voltages and test for shorts. I've seen shit like that drive people insane for hours upon hours and the problem was a trim screw pierced a wire when some random piece of trim went back on. it would help if posted a schematic of EXACTELY how you wired this thing up. __________________ -The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. *-Angry Motherfcker Mode ENGAGED-**

06-29-2010, 08:42 AM	#8
vex RCC Loves Me Not You Join Date: Jul 2008 Location: Influx. iTrader: (6) Posts: 2,113 Rep Power: 19	Solution: Don't use insulation tape to keep wires from grounding out. Use heat shrink, or run an entire new wire. __________________ The Official FC Radiator Thread My Project Thread: Cerberus CCVT Virginia Rotary Group

06-27-2010, 08:26 AM	#3
soldave Rotary Fanatic Join Date: Jun 2010 Location: Okinawa, Japan iTrader: (0) Posts: 134 Rep Power: 15	It's not. It's the 15A engine fuse in the fuse box next to the gas pedal

06-28-2010, 06:58 AM	#4
soldave Rotary Fanatic Join Date: Jun 2010 Location: Okinawa, Japan iTrader: (0) Posts: 134 Rep Power: 15	OK, progress report time. Pulled the 2-wire plug out of the main relay and turned ignition on - fuse blows Pulled the connector out of circuit opening relay and turned ignition on, fuse doesn't blow. Turn key and engine almost fires but then dies. Tested circuit opening relay and all the voltages & resistances came back ok. I then look at what the circuit opening relay does again, and go to the back to check my fuel pump relay I rigged up. One wire (blue and something) was loose so I reconnected it and put the connector back onto circuit opening relay. When ignition goes to "on" it's fine, but when it goes to "Start" it blows again. Then tried putting ignition to "on" and then connecting the fuel pump diagnostic switch (the yellow one in the engine bay). Sure enough, as soon as I connected it, the fuse blew. So it looks like my fabulous mechanical skills have failed somewhere again. Am going to have to check and probably redo all the wiring going to the pump and maybe get a new relay too

06-29-2010, 12:54 AM	#7
soldave Rotary Fanatic Join Date: Jun 2010 Location: Okinawa, Japan iTrader: (0) Posts: 134 Rep Power: 15	Pulled the blue wire and blew a fuse again when I turned the key, but thinking about relays got me thinking about the eliminated resistor relay at the front. Pulled the air filter out of the way and found some of the insulation tape I had on one of the soldered connections had come off, and typically it was resting on a grounding point. Insulated it again, reconnected the blue wire and turned the key. Engine fire up first time. Bingo. Another problem solved. Many, many more to go!

06-29-2010, 08:43 AM	#9
soldave Rotary Fanatic Join Date: Jun 2010 Location: Okinawa, Japan iTrader: (0) Posts: 134 Rep Power: 15	Heat shrink not as easy to come across here in Okinawa as you'd think.