LT1 coil rewiring mod
02-18-2017, 07:47 PM
#1
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Join Date: Oct 1999
Location: Crowded SW Florida
Posts: 320
LT1 coil rewiring mod
I've gotten my 1995 TA back on the road after demodding it, and am doing a few things to it for daily use.
I noticed it had a stumble around 1500 RPM and sometimes after sitting it really had to crank a long time to start. Cold stars are almost instantaneous. It occurred to me the coil and ignition coil module (ICM) have never been changed in at least 17 years (I bought it used). I've rewired a couple of my bikes so the coil sees battery power when cranking and it helped with starting.
This mod is incomplete as I am waiting for a new coil & ICM, but I got the wiring part done tonight.
Parts needed:
12v relay with socket, I used a sealed unit that had a mounting slot. You can find them on eBay or Amazon.
Automotive grade (such as TXL) wiring:
10 amp fuse
2x ring terminals
Heat shrink to cover rings and unused wires
Nylon loom for wires to coil
3 pin and 2 pin connectors, I used Weatherpack
Tools
10mm & 3/8 sockets, ratchet, and extension
Soldering gun
Process
I mounted the relay beside the battery and bolted it in place using the front fender bolt. The bracket extended out about 2.5" and this allowed the fuse holder to mount under it. I ran the ground wire to the factory ground point on the passenger side, and the battery feed from the factory junction box. The coil trigger and output wires were placed in some high temp loom and run across the engine to the coil area. I have a strut tower brace so I zip tied the loom to it, but it could be secured otherwise.
The wire you have to cut is the only one that does not come from the ICM. It was the pink wire on the black pigtail on my car. The diagram below has the wire colors from the ICM from the 1995 shop manual.
The attached diagram shows how to wire it vs OEM. I don't have any installed pics but the above in conjunction with the diagram should allow someone that wants to repeat the process to do so.
I noticed it had a stumble around 1500 RPM and sometimes after sitting it really had to crank a long time to start. Cold stars are almost instantaneous. It occurred to me the coil and ignition coil module (ICM) have never been changed in at least 17 years (I bought it used). I've rewired a couple of my bikes so the coil sees battery power when cranking and it helped with starting.
This mod is incomplete as I am waiting for a new coil & ICM, but I got the wiring part done tonight.
Parts needed:
12v relay with socket, I used a sealed unit that had a mounting slot. You can find them on eBay or Amazon.
Automotive grade (such as TXL) wiring:
- 12 gauge red (can use smaller), relay to coil pigtail and input from battery
- 18 gauge blue, ignition coil harness wire to relay coil
- 18 gauge black, relay coil ground
10 amp fuse
2x ring terminals
Heat shrink to cover rings and unused wires
Nylon loom for wires to coil
3 pin and 2 pin connectors, I used Weatherpack
Tools
10mm & 3/8 sockets, ratchet, and extension
Soldering gun
Process
I mounted the relay beside the battery and bolted it in place using the front fender bolt. The bracket extended out about 2.5" and this allowed the fuse holder to mount under it. I ran the ground wire to the factory ground point on the passenger side, and the battery feed from the factory junction box. The coil trigger and output wires were placed in some high temp loom and run across the engine to the coil area. I have a strut tower brace so I zip tied the loom to it, but it could be secured otherwise.
The wire you have to cut is the only one that does not come from the ICM. It was the pink wire on the black pigtail on my car. The diagram below has the wire colors from the ICM from the 1995 shop manual.
The attached diagram shows how to wire it vs OEM. I don't have any installed pics but the above in conjunction with the diagram should allow someone that wants to repeat the process to do so.
Last edited by Live for TAs; 02-18-2017 at 08:13 PM.
