Rostra install: an idiot's addendum

[bciesq]

I recently installed a Rostra cruise control on my 2000 Insight. I started with the same resources that everyone else turns to:

InsightCentral.net - Honda Insight Modifications - Cruise Control 2

InsightCentral.net - Honda Insight Modifications - Cruise Control 1

While these walkthroughs were invaluable, the Rostra kit has changed a bit over the years and the instructions were not idiot proof … at least not when faced with this idiot. Hopefully the following will be a useful update for others.

Ordering the Kit

I ordered the following part numbers from Brandon Distributing (877-402-3944) Brandon Distributing, Inc. - Accessories for your Car, Truck, SUV & RV :

250-1223

250-1483

250-4325

Joe Brandenburg was very helpful and the total cost came to $262.95.

Opening the Boxes

The basic components are easy to identify. The intimidating part comes when one looks at the baggies full of tiny parts. Know this up front: lots of these bits and pieces are not used.

Under the Hood

After you install the cable bracket and throttle adapter per the linked instructions, you need to prepare the cruise module’s throttle cable for use with the snap-in adapter (G-17). In order to use it you need to add threads to the throttle cable. Use one of the small lock nuts that comes with the kit (G-15) and a box end wrench to score about six inches of threads on the cable. Remove the lock nut and then thread on the snap-in adapter about half way up the newly scored throttle cable with the top of the pyramid pointing towards the end of the throttle cable. Next you need to prepare the end of the throttle cable to attach to the throttle adapter. The linked instructions are very good, but the current version of the kit is a little different. First, you do not need to use the bead chain on this version of the control unit as it automatically compensates for slack. The eyelet connector (G-8 ), one bead connector (G-4) and a cotter pin (G-16) are the only parts you need to attach the cruise control’s throttle cable to the throttle adapter in the current version of the kit. Many of the orphaned bits and pieces come from this step.

After the throttle cable is ready, snap the adapter (G-17) in to the cable guide. The eyelet connector should slip over the throttle adapter easily; in fact, the eyelet is pretty loose on the adapter. Before you install the cotter pin, make sure that the cable does not have too much slack. The goal is to have the same amount of slack as engine’s throttle cable. The slack is adjusted by varying the position of the snap-in connector on the throttle cable through trial and error. I started out with the snap-in connector threaded about three inches up on the throttle and had move it down another half of a inch to get the desired tension. Finish by inserting and securing the cotter pin on the throttle adapter.

After you mount the cruise control module (I used the supplied bracket; electrolysis be damned … I’m a rebel like that), and attach the ground wire and plug in the wiring harness, you are basically finished under the hood. If you haven’t already had a beer, now is a good time to get one.

Under the Dash

Per the linked instructions, start by removing the grommet on the heater control cable and running the two four wire connectors that you’ve removed from the wiring harness through this hole from the inside of the car to the engine bay. This is a very frustrating process. Take your time.

On my MT Insight, I had to install a clutch switch. The same quirk as noted in the instructions still exists on the latest kit in that you need to cut the two-prong connector from the switch and then connect the violet wire to one of the wires and the then tap into the brake light negative wire (green/white) with the other. I had to add some wire to the clutch switch in order to reach the brake light negative wire. The red wire from the harness then taps into the brake light positive wire (white/green).

I used the fuse for the accessory plug to tap for power (brown wire with the spade end on the wiring harness). I then tapped that same brown wire with the brown wire from the RF control. I made this tap after the in-line fuse.

The blue wire still isn’t used. I attached it to ground along with the ground wire from the RF control.

The gray VSS wire is still attached to the blue/white wire on the 31 pin blue connector under the passenger side floor. This connector is towards the outside (right) of the car. Unplug it and cut away some of the insulation to get enough slack to use one of the Scotch connectors (G-22).

On my version of the RF control there is a two-prong plug that I didn’t use. There is also a plug on the wiring harness in the engine bay that I didn’t use. Just leave them hanging; the system works fine without connecting them to anything.

Hope this helps.

[catawalks]

Nice write up, very detailed. Probably not needed but pictures might help a little.

Also, I was looking around on that site and couldn't find the last part you listed:
250-4325. What is that exactly and where on the site would I be able to find it? Apparently looking up the part numbers in their search yields no results.

[bciesq]

250-1223 - Cruise control module

250-1483 - RF Switch

250-4325 - Adapter

I placed my order by phone/email.

As for pictures, the linked instructions provide good images. If you need something in particular, just post or PM and I'll help out if I can.

[Valgul]

At what points during the installation would the car be undrivable? Could this be installed over a period of a couple of weeks and still be able to use teh car? Or once you start, the car cannot be used until finished.

[bciesq]

Originally Posted by Valgul

At what points during the installation would the car be undrivable? Could this be installed over a period of a couple of weeks and still be able to use teh car? Or once you start, the car cannot be used until finished.

I installed mine over a couple of days and then a week went by while I had to trouble shoot a wiring problem (spoiler alert: it was the VSS wire, natch). I drove the car off and on the entire time.

You will have to exercise some common sense obviously. After you attach the cruise control throttle cable, make sure that you've adjusted the slack properly before you drive. Otherwise, as long as everything is secured and out of the way, you can drive the car before finishing the job.

If you are doing this in stages, then the point at which I recommend getting a beer is a good stopping place. At that point, you've finished installing everything under the hood. Other than the ground wire, you haven't hooked up any wires and the cruise control unit will not interfere with the normal driving of the car in this state. Just use common sense and make sure that everything is out of the way, i.e., no bits dangling near drive belts or sources of extreme heat like the cat or exhaust manifold.

As for the wiring, as long as you use the included Scotch taps, you won't be cutting any wires that are native to the car, so you should be OK. Once you start the wiring work, I wouldn't drive the car until after all the ground wires are in place.

[aisbell]

Originally Posted by bciesq

Per the linked instructions, start by removing the grommet on the heater control cable and running the two four wire connectors that you’ve removed from the wiring harness through this hole from the inside of the car to the engine bay.

I am at this stage of the Rostra installation and would like some clarification.

Did you somehow pull the heater control cable grommet into the inside of the car or did you pop it out of its hole from under the hood? Access from the engine compartment seems very difficult. But pulling it inside the car also seems like it might be difficult because it's recessed a bit with access being a hole about the same size as the grommet.

Do the two 4-wire connectors end up in the engine compartment? If so, is there sufficient harness length inside the car to make all necessary connections?

Did you run the cruise control harness through the grommet and then insert the grommet back in its firewall hole? With both the heater control cable and cruise control harness wiring in the grommet, I would think that putting it back in its firewall hole would be difficult.

Any tips or suggestions would be welcome!

[Mike Dabrowski 2000]

For the people with the plug and play MIMA harness, you can pick up the VSS wire on the distribution board.
MIMA Honda Insight Modified Integrated Motor Assist - Expanding MIMA with the Distribution board ( users projects )

[aisbell]

Originally Posted by Mike Dabrowski 2000

For the people with the plug and play MIMA harness, you can pick up the VSS wire on the distribution board.

Thanks for the tip! I was at least clever enough to realize that both the Rostra and MIMA required ECM access, so I had planned to install the MIMA ECM components when I tapped into the VSS wire at the ECM for the Rostra. But now I'll plan to install the MIMA distribution board as well so that I can tap into the VSS signal there.

Now if only I could get some warm weather so my fingers will function while performing these installations… <looks outside at snow flurries >

[bciesq]

Originally Posted by aisbell

I am at this stage of the Rostra installation and would like some clarification.

Did you somehow pull the heater control cable grommet into the inside of the car or did you pop it out of its hole from under the hood? Access from the engine compartment seems very difficult. But pulling it inside the car also seems like it might be difficult because it's recessed a bit with access being a hole about the same size as the grommet.

Do the two 4-wire connectors end up in the engine compartment? If so, is there sufficient harness length inside the car to make all necessary connections?

Did you run the cruise control harness through the grommet and then insert the grommet back in its firewall hole? With both the heater control cable and cruise control harness wiring in the grommet, I would think that putting it back in its firewall hole would be difficult.

Any tips or suggestions would be welcome!

I pulled the grommet from inside the car with needle nose pliers. It didn't tear or deform and could be reused.

As for the connectors, yes, they end up in the engine compartment and I had more than enough wiring length inside the car except for the one instance that I noted re: the clutch switch.

The grommet is just hanging out on the heater control cable. I didn't see how to reinstall it with the additional wiring now occupying the hole. I haven't had any problem with water intrusion. This seems to be par for the course. From the instructions I linked to before:

Replacement of the Honda heater valve control cable firewall grommet with a generic grommet provided the firewall pass-through I needed (sealed with silicone caulk). In fact, I left the original grommet on the heater valve cable. If I remove the cruise control, the grommet will slide right back where it came from, restoring the original configuration. Super.

As I recall, I did take some precaution to prevent chaffing, but that was it.

Hang in there. It's frustrating, but the system works pretty well once it's installed.

[aisbell]

Originally Posted by bciesq

Hang in there. It's frustrating, but the system works pretty well once it's installed.

Thanks for your quick response to my questions. I now know how to proceed. Maybe surrounding the heater control cable and cruise control wiring with some silicone rubber sealant where they pass through the firewall will keep out any water and prevent chafing.

I'm trying to install both MIMA and the Rostra at the same time, so there's lots to do. I will be posting some additional information about my Rostra installation experience after I finish.