I am making progress on my air throttle project with the end goal of eliminating the King unit. I've got the air hose run, pedal (treadle) installed, throttle control cylinder installed and the TPS (throttle position sensor) installed BUT I can't find the Allison TPS wires & plug. Anyone know where they are?
I'm looking in the bundle at the transmission and in the bundle in the engine compartment that feeds the King unit. I found a plug near the King that fits the TPS but the wire numbers indicate they are for "Throttle Cruise." I found another one but it has only two wires. Anyhow, does anyone happen to know where I can find this elusive plug? Thanks.
jor
John,
I'll get out in the morning and look at our TPS. Will try to see where the signal output wire goes. Too hot to look right now - 95 in the shade and going to 100 every day this week. I think summer has really arrived in West TX.
Jor:
Not for sure this is what you are looking for.
Steve at King Control, told me the TPS data is fed from the King Control Unit and the attached drawing is mis-labeled, the arrow is pointing to a FILTER and not a TPS Sender. Steve said the system works without the filter. So I assume this plug is sending the TPS data to the Allison, hope this helps. Following your progress, best of luck in the conversion.
Regards,
I hope someone makes a detailed you tube video of the procedure.
Another vote for a real detailed write up and video. Many of us will be in your debt.
I'll post a good write-up when I get done. I'm making progress slowly. As far as I know only one other member has done the conversion himself and I have a PM into him. I went by the schematic that cry42 posted (thanks) and I found the connector from the King for the King TPS. The wire colors on the King unit are consistent with that schematic.
The wires on the chassis side, however, are of different colors than on that schematic. There are three wires in what appears to be a factory tape wrap and a 4th that may have been added. The three wires are numbered. The numbers are 124, 156 and 203. The extra is not numbered and I suspect it must have been used in the King installation. Anyhow, I checked an Allison schematic and i see the three TPS wires coming from the transmission. They are numbered 124, 156 and
135. That "135" was disappointing.
I'm going to check the origin of those wires at the transmission and see if the numbering is consistent. Anyhow, slowly but surely.
jor
John,
Here's the photos of the transmission TPS on our coach. Not great, but best I could do.
The wires coming out of the TPS are red, blue and green. They disappear into a slit wiring loom. Where they go after that - no idea.
Tried to get a shot of the TPS/throttle cable bracket. Also not great photos.
Chuck, these photos are helpful. Thanks. I have the same three colors and am going to trace back to the transmission to make sure they are consistent as the number on my green wire differs from that on the Allison schematic. Also, I am interested in the linkage at the engine. Thanks.
jor
The TPS linkage is hard to photograph - can't get my phone down there at a good position.
The TPS cable end is a flat metal piece with a slot in it. The slot fits over a post on the engine fuel control lever. When the fuel control lever is moved by the throttle cable, the post moves until it reaches the end of the slot, then the TPS cable moves. I found another post with a better photo of the TPS linkage:
King Cruise Closed - suggested replacement? (https://www.foreforums.com/index.php?topic=40033.msg401234#msg401234)
The apparent aim of this setup is to allow a certain amount of movement in the fuel control lever before the TPS receives any input. Document below shows how to adjust the TPS.