98 Honda Accord EX help!

Couple of things if you're doing the 551T in a Honda.  Firstly, the range of most factory remotes generally sucks, but you already know that.  The other is that with the motor running, the keyless is disabled--try it for yourself.  So after you've remote started the car, you'll be forced to use the key to unlock it to get in.

You might possibly be able to operate the power door locks, while listening closely to the sound of the factory relays---if you can find the factory keyless module, one of the wires there should test as ignition.  Use a relay to interrupt this wire during remote start, then the keyless will work.

I've only done a few of these cars, but you usually can get tach inside, rather than underhood.  Look high up in the driver's underdash toward the left side; you'll probably find several blue wires there.  Test each until you find the right one.

Anyway, here are the wire colors:

|       ITEM      |     WIRE COLOR     |POL|       WIRE LOCATION        |

|              12V|white               |+  |ignition harness            ||          STARTER|BLACK/ white *1      |+  |ignition harness            ||         IGNITION|BLACK / YELLOW        |+  |ignition harness            ||  SECOND IGNITION|yellow              |+  |ignition harness            ||        ACCESSORY|WHITE/ black         |+  |ignition harness            ||       POWER LOCK|BLACK/ blue *2       |-  |passengers fuse box *3      ||     POWER UNLOCK|orange              |-  |passengers fuse box *3      ||       LOCK MOTOR|WHITE/ red           |   |drivers fuse box            ||     UNLOCK MOTOR|*4                  |   |drivers fuse box            ||    DISARM DEFEAT|lt. GREEN/ red       |   |*5                          || PARKING LIGHTS +|RED / black           |   |drivers fuse box            || PARKING LIGHTS -|RED / yellow *6       |   |steering column             ||       HEADLIGHTS|blue/red            |-  |steering column             ||     DOOR TRIGGER|BLACK/ white         |-  |passenger fuse box *7       || DOME SUPERVISION|use door trigger    |   |                            ||  TRUNK/HATCH PIN|orange              |-  |drivers kick panel *8       ||         HOOD PIN|                    |   |                            ||TRNK/HTCH RELEASE|WHITE/ red           |+  |drivers kick panel          ||  FCTRY ALARM ARM|*9                  |   |                            ||FCTRY ALRM DISARM|*9                  |   |                            || DISARM NO UNLOCK|blue                |-  |*10                         ||       TACHOMETER|blue                |   |tach test connector *11     ||      SPEED SENSE|blue/white          |   |*12                         ||       BRAKE WIRE|WHITE/ black         |+  |brake pedal switch          ||     HORN TRIGGER|lt. GREEN/ blue      |-  |steering column             ||           WIPERS|                    |   |                            ||  LF WINDOW UP/DN|RED / yel - RED / blu   |A  |drivers door switch         ||  RF WINDOW UP/DN|blu/wht - blu/yel   |A  |RF window switch            ||  LR WINDOW UP/DN|RED / yel - RED / blu   |A  |LR window switch            ||  RR WINDOW UP/DN|RED / yel - RED / blu   |A  |RR window switch            |

Notes:

NOTE:  This vehicle has an immobilizer system that needs to be bypassed when adding remote start.  Use DEI part number 555U.  *1 Must interrupt the wire between the keyswitch and the fusebox, not between the fusebox and the starter, to keep the check engine light from coming on.    *2 Use BLACK/ white for lock and GREEN/ red for unlock on LX models without factory security.  These wires are located in a two pin gray connector by the front of the drivers side fuse box.  *3 in a green 20 pin connector.  *4 yellow on the EX and lt. GREEN/ red on the LX  *5 located in the same plug as the door lock wires.  Also found in a 14 pin green plug at the drivers fuse box on the EX model.   *6 Only available on the EX model.  *7 In a green 4 pin connector.  *8 Above the hood release in a gray 18 pin connector.  On the DX & LX models, also found in a 2 pin connector behind the drivers fuse box.    *9 Arms and disarms with the door locks on the EX models.  The LX models arm only with the factory transmitter.    *10 On the EX the wire is located at the drivers power window switch, on the LX the wire is at the keyless/security unit which is attached to the drivers underdash panel.   *11 The tach test connector is located behind the battery on the 4 cylinder, and on a bracket attached to the drivers side strut tower on the 6 cylinder motor.  The tach test connector is a white 2 pin connector, and may be covered by a black rubber boot.  *12  Located at the first plug on the ECM, it is a 32 pin gray plug. The ECM plugs can be accessed by pulling up the carpet on the passenger side of the center console.  There are 4 plugs total.

could someone actually tell me where the factory alarm is?... and what am I supposed to be listening to?

The 551T has the igniton blocker relay set up into it... and well... it tells me where the LX one is located at... too bad I need to know where the EX one is....

This post might be too late but anyways... From what I can remember the factory alarm for the EX Accord is located under the passenger dash, close to the kick panel up high. You will have to remove the underside panel to get to it. Just click the keyless and hear the relays. You will also need to use the 555u for the immobilizer. You can also get the tach wire behind the instrument cluster.

Thank you very much... you wouldn't happen to remember the wiring colors of the harness wouldd you?.. or what it says on the thingy would you?... because I never had to use a multimeter and I really don't know how to use one :-(... I heard there are some wires you really DON'T want to probe... so I usually just go with wire colors.. etc.

what do I do for testing negative wires?