proven TC88A ignition that is compatible
with 2004-2006 American IronHorse models. The
TC88A-IH version has special firmware that provides
the tach signal required by the IronHorse instrument
module and proper dwell control for the original
equipment (OE) ignition coils. You cannot use a
standard TC88A unit. Installation involves cutting off
the OE 18 terminal AMP connector used with the Gill
module and replacing it with a 12 terminal Deustch
connector supplied with the TC88A-IH kit. On 2005 and
later models, some minor rewiring of the MAP sensor
and engine temperature sensor ground connections is
required.
The TC88A-IH offers adjustable advance and
adjustable RPM limit settings in 100 RPM increments.
The TC88A-IH also features built-in data logging that
stores data for the last 30 minutes of engine operation
including RPM, manifold pressure, ignition advance,
and battery voltage. Engine builders will find the data
logging feature highly useful for tuning, diagnosing
problems, and reducing unjustified warranty claims.

Figure 1 TC88A-IH Ignition Module


Twin Tec PC link software along with an optional
USB interface cable (P/N USB-INTF) and power
adapter (TC88A-ADAPT) allow the use of a laptop PC
to program a custom advance curve for precise dyno
tuning and download data logged by the unit.
INSTALLATION OVERVIEW
Before proceeding you must have access to a
proper Deutsch crimping tool and experience with the
Deutsch connectors. For more information, you can
refer to the Deutsch connector section in any recent
Harley-Davidson electrical diagnostic manual. On
2005 and later models, some wires will have to be
extended. Solder all wire joints and cover with shrink
tubing.
INSTALLATION ON 2004 MODELS
1. Turn off the ignition switch and disconnect the
battery ground cable before proceeding.
2. Refer to Figures 2 and 3 for wiring details.
3. Remove the Gill Module.
4. Cut off the OE 18 terminal AMP connector used
with the Gill module. Refer to the terminal list.
Crimp new Deutsch terminals on the wires, and
install into the 12 terminal Deutsch connector
required by the TC88A-IH module.
5. Install the new TC88A-IH module.
6. Reconnect the battery ground cable.
INSTALLATION ON 2005 AND
LATER MODELS
1. Turn off the ignition switch and disconnect the
battery ground cable before proceeding.
2. Refer to Figures 4 and 5 for wiring details.
3. Remove the Gill Module.
4. Cut off the OE 18 terminal AMP connector used
with the Gill module.
5. The crankshaft position (CKP), MAP, and engine
temperature (ET) sensor share a common ground

Daytona Twin Tec LLC, 933 Beville Road, Suite 101-H, S. Daytona, FL 32119 TC88A-IH
(386) 304-0700
www.daytona-twintec.com

4/2007
Page 2
return. This is not compatible with the TC88A-IH
and some rewiring will be required. The
temperature sensor is not used, but does not
require removal.
6. Trace the BK/GN ground return wires from terminal
B of the ET sensor and terminal A of the MAP
sensor to where they join the BK/GY ground return
wire from the CKP sensor. Cut the ET and MAP
sensor ground return wires off at this point. You
can tape up the ground return wire from the ET
sensor this wire will not be used.
7. Extend the ground return wire from terminal A of
the MAP sensor up to the ignition module, crimp on
a Deutsch terminal and install in position 4 on the
Deutsch connector.
8. Refer to the terminal list. Crimp new Deutsch
terminals on the remaining wires, and install into
the 12 terminal Deutsch connector required by the
TC88A-IH module.
9. Use a DVM to verify isolation (no continuity)
between terminals 4 and 9 on the Deutsch
connector.
10. Verify continuity between terminal A at the MAP
sensor and terminal 4 on the Deutsch connector.
11. Verify continuity between terminal 2 at the CKP
sensor and terminal 9 on the on the Deutsch
connector.
12. Install the new TC88A-IH module.
13. Reconnect the battery ground cable.
Terminal List for American IronHorse Ignition Conversion
TC88A Deutsch Connector
OE AMP Connector

Signal
Wire Color Code
1



2



+12V Power
W/R
2



15



Tach

W/V
3 4 Sensor
Power
GN
4



N/A



Sensor Ground 2005 and later models only
5 1 Module
Ground
BK
6 8 Coil
Front
(#1)
BN/GY
7 14
Coil
Rear
(#2)
GY/R
8 6 CKP
Sensor
Signal
R/BK
9 5 CKP
Sensor
Return
BK/GN
or
BK/GY
10
N/A
VSS
Input

not
used
11
17
MAP
Input
Y/R
12
N/A
J1850
Serial
Data

not
used
Wire Color Codes
Color Code
Color
BK
Black
BN
Brown
R Red
O Orange
Y Yellow
GN
Green
BE
Blue
V Violet
GY
Gray
W White
PK
Pink
TN
Tan


Daytona Twin Tec LLC, 933 Beville Road, Suite 101-H, S. Daytona, FL 32119 TC88A-IH
(386) 304-0700
www.daytona-twintec.com

4/2007
Page 3
Figure 2 2004 American IronHorse OE Ignition Wiring Diagram
2
1
CKP RETURN BK/G
CKP SIGNAL R/BK
A
B
C
SENSOR GND
MAP INPUT Y/R
SENSOR PWR GN
GROUND BK
MAP
SENSOR
GILL IGNITION
MODULE
CRANKSHAFT POSITION (CKP) SENSOR
+12V POWER W/R
COIL
REAR GY/R
COIL
FRONT BN/GY
T
ACH W/V
17 4 1 2 8 14 6 5 15
INSTRUMENT CLUSTER
GILL IGNITION COILS
TO FRONT
SPARK
PLUG
TO REAR
SPARK
PLUG
TO +12V





Daytona Twin Tec LLC, 933 Beville Road, Suite 101-H, S. Daytona, FL 32119 TC88A-IH
(386) 304-0700
www.daytona-twintec.com

4/2007
Page 4
Figure 3 2004 American IronHorse TC88A-IH Ignition Wiring Diagram
2
1
CKP RETURN BK/GY
CKP SIGNAL R/BK
A
B
C
SENSOR GND
MAP INPUT Y/R
SENSOR PWR GN
GROUND BK
MAP
SENSOR
CRANKSHAFT POSITION (CKP) SENSOR
+12V POWER W/R
COIL
REAR GY/R
COIL
FRONT BN/GY
T
ACH W/V
11 3 5 1 6 7 8 9 2
INSTRUMENT CLUSTER
GILL IGNITION COILS
TO FRONT
SPARK
PLUG
TO REAR
SPARK
PLUG
TO +12V
MODE
ADJUST
INITIAL ADVANCE
TIMING SLOPE
X1000 X100
RPM LIMIT
78
90
1 2 6 543
78
90
1 2 6 543
78
90
1 2 6 543
78
90
1 2 6 543
TC88A-IH IGNITION MODULE



Daytona Twin Tec LLC, 933 Beville Road, Suite 101-H, S. Daytona, FL 32119 TC88A-IH
(386) 304-0700
www.daytona-twintec.com

4/2007
Page 5
Figure 4 2005 and Later American IronHorse OE Ignition Wiring Diagram
2
1
CKP RETURN BK/GY
CKP SIGNAL R/BK
A
B
C
SENSOR GND BK/GN
MAP INPUT Y/R
SENSOR PWR GN
B
A
GROUND BK
MAP
SENSOR
GILL IGNITION
MODULE
ENGINE TEMP
(ET)
SENSOR
CRANKSHAFT POSITION (CKP) SENSOR
ET RETURN BK/GN
ET SIGNAL
PK/Y
+12V POWER W/R
COIL
REAR GY/R
COIL
FRONT BN/GY
T
ACH W/V
17 4 1 2 8 14 6 5 15 18
INSTRUMENT CLUSTER
GILL IGNITION COILS
TO FRONT
SPARK
PLUG
TO REAR
SPARK
PLUG
TO +12V




Daytona Twin Tec LLC, 933 Beville Road, Suite 101-H, S. Daytona, FL 32119 TC88A-IH
(386) 304-0700
www.daytona-twintec.com

4/2007
Page 6
Figure 5 2005 and Later American IronHorse TC88A-IH Ignition Wiring Diagram
2
1
CKP RETURN BK/GY
CKP SIGNAL R/BK
A
B
C
SENSOR GND BK/GN
MAP INPUT Y/R
SENSOR PWR GN
B
A
GROUND BK
MAP
SENSOR
ENGINE TEMP
(ET)
SENSOR
CRANKSHAFT POSITION (CKP) SENSOR
ET RETURN BK/GN
ET SIGNAL
PK/Y
+12V POWER W/R
COIL
REAR GY/R
COIL
FRONT BN/GY
T
ACH W/V
X X
NOTE: CUT AND TAPE UP
ET SENSOR LEADS.
ISOLATE CKP RETURN AND
MAP SENSOR GROUND.
TEST WITH DVM TO VERIFY
ISOLATION (NO
CONTINUITY) BETWEEN
TERMINALS 4 AND 9.
INSTRUMENT CLUSTER
GILL IGNITION COILS
TO FRONT
SPARK
PLUG
TO REAR
SPARK
PLUG
TO +12V
11 3 5 1 6 7 8 4 2 9
MODE
ADJUST
INITIAL ADVANCE
TIMING SLOPE
X1000 X100
RPM LIMIT
78
90
1 2 6 543
78
90
1 2 6 543
78
90
1 2 6 543
78
90
1 2 6 543
TC88A-IH IGNITION MODULE



Daytona Twin Tec LLC, 933 Beville Road, Suite 101-H, S. Daytona, FL 32119 TC88A-IH
(386) 304-0700
www.daytona-twintec.com

4/2007
Page 7
RECOMMENDED TIMING SETTINGS
The American IronHorse engine utilizes a non-
adjustable crankshaft position sensor. Thus no
mechanical means exist for adjusting the timing. The
TC88A-IH module overcomes this limitation. The initial
timing switch allows you to shift the entire advance
table up or down. Lower switch settings decrease
(retard) the initial timing and higher switch settings
increase (advance) the initial timing in one-degree
steps.
The TC88A-IH module accommodates a wide
range of engine applications. The advance slope
switch allows you to control the aggressiveness of the
ignition advance. Figures 6-8 show the effect of
advance slope switch settings. Each figure shows
advance curves for various manifold pressure values.
Higher switch settings result in more aggressive
advance. The effect is more pronounced at high
manifold pressures. Note that 30 In-Hg manifold
pressure represents wide open throttle (WOT) and 16
In-Hg represents deceleration conditions.
For most applications, initial timing setting 2 and
advance slope setting 1 should eliminate any spark
knock encountered with stock engines. The TC88A
Tech FAQ on our website also has a custom advance
table that you can download for modified high
compression IronHorse applications provided by
courtesy of Proven Performance.
Tuning a particular engine setup always requires
some trial and error experimentation, but maximum
power is usually obtained b