ALLSCION DISCLAIMER: Most people who install the cruise control themselves are either technically or mechanically inclined. If you are not comfortable working on cars, we recommend you use a professional installer. Please e-mail us if you need one, and we'll find one in your area.

These comments are from three customers, Clifford Flath, Neil Adler and Ethan Upper, based on their experiences installing the Rostra cruise control in their Scions. The comments reflect their opinions, and not that of Allscion or Rostra.

Clifford Flath's installation remarks
Step #1-2:
Should not instruct to remove the grommet. It doesn't help to remove it, and it's terrible to get back in. It should also say that the grommet has an outer membrane and an inner membrane and both need to be cut.

Step #2:
Good.

Step #3-2
On mine it was impossible to use the factory cable clip. I just ignored this instruction.

Step #4-3
I have no suggestion regarding this step, but there's no way anyone will ever get a torque wrench in there to tighten this nut. A little more instruction about how to do this would help. Is it okay to take the throttle to the stop and then torque it, or might that harm something? Mine is tightened as tight as I could get it by holding the pulley segment with my free hand. Is that tight enough -- I don't know, actually.

Step #6:
Good.

Step #7:
Good. Except perhaps add: be careful not to damage the wires from the switch as the switch assembly is turned.

Step #8:
This step could be improved.

First, it's almost impossible to twist one's head around to see what is in figure 16B and even more difficult to remove connectors and add a wire.

Figure 16A is a cumbersome picture and tells me nothing

Why refer to 1N when it's not written anywhere in my Scion XA?

Is picture 16C the pin side of the connector or the wire side? -- I still don't know.

After much cursing, I finally got to the connector that I thought was the correct one and unplugged it, but there was no green wire. So, I thought I had the wrong connector. I painfully removed the adjacent (outboard) and found no green wire there either. After rereading the instructions, I noticed that an XB has a black & white wire. Since I had a black & white in the first removed connector and it was a fairly big wire and it was either in position 6 or 10 depending on whether figure 16C is pin side or wire side, I assumed the instructions made a mistake and the black and white was the wire I was looking for. So I painfully attached my brown wire there -- it didn't work.

My fix was to go to AutoZone and a get an add-a-circuit fuse, which I put in the unused fuse slot above the 15 amp ACC fuse. The add-a-circuit fuse is far superior to the procedures in step #8, and in my opinion should be included in the Scion cruise control kit.

Step #9:
This step isn’t very good either.

Why specify connector numbers when the numbers aren't written anywhere on my XA?

Figure 20 is too poor to determine which connector is the one needed. Figure 19 is the pin side of the connector, which is not specified, and since the installer never sees the pin side, the installer would assume the picture is of the wire side. This makes for confusion, especially since the installer doesn't know at the time figure 19 is studied which connector is the one needed.

This instruction should have just said: VSS is on the second connector from the right, the rightmost wire in the second row up, which is a violet & white wire.

Step #10:
Good. Except the instructions should specify if the hole is drilled in front or in back of the rib on the inside of the column cover. If I followed the 5/8" instruction, the hole came out on the rib. I mounted mine to the back of the rib (closer to the steering wheel) and it seems to me to be the ideal position for the control.

My XA is a manual, so I have no idea if there are any problems finding the NSS wire.

My cruise control works very fine. I'm happy I bought it. All the parts (except step 8) fit nicely. The control module location works well. The throttle actuator fits easily and correctly on the throttle shaft. The connectors for splicing into the brake switch and the included new clutch switch are Scion-specific and fit perfectly. The kit is designed for the Scion, and results in a nice installation."

It took me about 3 hours to install it. If I installed another one, it would take about one hour assuming I used an add-a-circuit fuse.

I'm a retired computer repairman.

Hope this helps.

Neil Adler's installation remarks:

The mechanical portion of assemble is relatively easy, the electronic portion is confusing because of the overly hard-to-decipher diagrams. It took about 4½ hours and works well. Look at these comments along with Clifford Faith's comments and the manual.

Step 1 and 2
I agree, do not remove Main Wiring Grommet, simply cut it on engine side, punch a screwdriver through, then cut in interior and threar Cruise Harness through.

Step 3
Cable Assembly follows Vehicles Throttle cable, but cannot easily tie to it or fit in cable clip. Doesnt seem to matter as long as free and not kinked.

Step 4
#1. Hard to see which cable nut is "rear", but either of the 2 will accept Throttle Lever bracket, and won't matter as long of length is adjusted to slight slack (0.06 - 0.10) The comments on the bottom of page 5 in box below #5 say to remove threaded snap in connector to adjust slack but don't say how. Take a screwdriver and gently pry out the fitting. Then is is easy to adjust and readjust until there is slight play. Again not critical I think.

Step 6
Brake switch is the black connector at the top of brake pedal, not the white one further up under dash.

Step 8
This is where the instruction fails. You cannot intepret or find the so called Black 1N connector or wire 6. Ignore all diagrams. What is needed is only to get ignition switchable power to the brown wire of the Harness Assembly. This is easily done by cutting off its connector and clamping or soldering a 'U' connector on and then placing this on an unused terminal of the front of the fuse box. You can test or trial and error for a power slot that is switchable, i.e. has power only when ignition is on. Since the cruise has 2 fuses of its own I can't see why you need to use the specific #6 wire as mentioned. Mine is working perfect. For what it's worth, Fig 16C and Fig 19 do refer to pin side connectors, thus are mirror images to what you see.

Step 9
Really easy, as Clifford states, VSSin #17s on second connector from right, wire is second row up , righmost violet and white wire. By same method NSS is Third row up, right most Black wire. Snap on connectors work well and fit under snap on plastic cover.

Step 10
This was hard until I realized the lower steering cover has 3 screws and requires rotating the asymetrical steerng wheel to access. When you measure carefully you will drill precisely at a plastic fin on the back side, which you must trim or tear off with pliers to get shroud, lock and jam nuts to fit. The location came out fine, and can be further adjusted for precise access.
When finally attaching to control switch to module assembly remember to use the 4 pin adn 2 pin connector housings in the parts, or you may blow the 4 amp fuse as I did.

The only parts left over were the clutch assembly (mine is automatic) and the larger M-6 bolt which I am yet to find.


Ethan Upper's installation remarks:

Step 1
Definitely no need to remove the grommet. Just make the cuts with an Xacto knife in the place shown, on the inside and outside membrane. I taped a length of thin wire to a screwdriver and poked it through the slit in the grommet. Then I wrapped the wire around the cruise harness and used a 'pull-feed" to get it through. This was the step I was most nervous about since it involved actually cutting into something, but it was no big deal. The supplied putty works very well for sealing the slit around the cruise harness.

Step 2
No major problems, but the mounting bracket forced me to install the control module at an angle, with the front canted upward, in order to accommodate the throttle cable that runs beneath it.

Step 3
I was not able to run the cruise throttle cable through the throttle cable clip (unless I wanted to bend it at an awkward angle), nor was there really a convenient place to use wire ties to secure it. I did loop one around the cruise throttle cable and engine throttle cable right next to the throttle cable clip, but I didn't tighten it. I don't think there will be a problem.

Step 4: This step took some fiddling to figure out and get right. You will probably want to remove the throttle cable bracket (Part 2A) from the cable before attaching to the OE throttle cable. Unclip the plastic 'Threaded Snap-In Adapter" from the cable bracket. I had already attached everything before I realized that I had about 3 inches of slack in the cruise throttle cable, so I had to remove the cable bracket, unclip the threaded adapter from the bracket, adjust the threaded adapter and then reassemble everything. I don't own a torque wrench, so I just tightened everything as tight as seemed prudent.

Step 5: Where is step 5??? I don't see a step 5! Oh well…Moving on.

Step 6: Piece of cake.

Step 7: (My xB is an automatic transmission so I skipped this.)

Step 8: This was a VERY frustrating step. But I don't think it has to be, and I figured it out without changing anything or buying any other parts. I read the other installation notes and decided I wanted to do it the way the manual said. I tried unsuccessfully for about 30 minutes to disconnect the connector and then left it and moved on. After I finished with everything else, I went up and got a flashlight and borrowed a small handheld mirror from my wife. Using those I was able to identify the wire running to pin #6 and fish it out enough to get the T-tap connector on it. In the xB at least, it is indeed a black/white wire. The diagram shows you the pins with connector facing you, as if you were going to plug it into your face. (Hee hee) So the wire you're looking for is on the bottom row, the second wire in. (Starting from the outboard side of the car.) I got the right wire, as my cruise control works perfectly and only switches on with the ignition.

Step 9: No problems. Just had to take it slow and make sure I had the proper connector for my vehicle and matched up the wires properly. Keep in mind that the diagrams show the pins with the the plug's 'business end" facing toward you.

Step 10: No problems at all. Good instructions. Had to clean up the hole with the Xacto knife and remove a little bit of the inside reinforcing rib.

In conclusion: I had intended on getting a professional installer to take care of this for me, but now I'm glad I just did it myself. When I first read the instructions and looked at the tangled wiring harness I was pretty apprehensive. I don't generally work on cars, but I am trained as an electronic technician and I guess some of the basic skills came in handy. The other installation notes on this site were VERY helpful. I read through the whole manual about three times first, which I would recommend.

This will sure make my upcoming 3500 mile road trip a lot easier!