Need Pic help...

[SCOTI]

I'm fixing several wiring related issues while reassembling the dually. Since things were removed from the engine bay, cleaned, stored, moved, etc, I seem to be missing 1 or 2 items.

One such item is the kickdown switch for the th400. I have the wire exiting the harness for this 'switch' but I don't know what it looks like or where it was installed originally (I stripped a bunch of stuff off the firewall @ the beginning of this swap to fix some paint related items).

This is on an 89 tbi 7.4l combo so any help is appreciated.

[baclay9]

The kick down switch is under the dash and is triggered by the go pedal.
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[SCOTI]

Originally Posted by baclay9

The kick down switch is under the dash and is triggered by the go pedal.

I've understood this as well.... That being said, I have an orange wire exiting the main wire loom where the ignition wiring also exits (for the distributor & coil pigtail). Looking @ the GM tech wiring diagram I have, it lists an orange wire in the same general area that goes to a 'kick-down solenoid' for the th400 hence my confusion.

I have a wire that exists, but doesn't have anything to connect to. The service manual shows that there was a firewall mounted switch/solenoid so I'm trying to determine what one looks like to see if that might be what I'm missing.

I need to determine what this orange wire goes to & where it's supposed to go.

[54Caddy]

the one for the th400 will be a spade style connector with a round black boot on it. If i were you i would just have a buddy tug the wire lightly from the insdie and feel if it is the same wire. more than likely it is because theres not many orange wires. green for coolant, tan for battery, and i believe its a brown wire for oil pressure.

[SCOTI]

Originally Posted by 54Caddy

the one for the th400 will be a spade style connector with a round black boot on it. If i were you i would just have a buddy tug the wire lightly from the insdie and feel if it is the same wire. more than likely it is because theres not many orange wires. green for coolant, tan for battery, and i believe its a brown wire for oil pressure.

This wire has a flat, female, style terminal encased in a black boot.

[SCOTI]

I took some pics to show what I'm working with. I looked under the dash again just to make sure there was no obvious separate switch @ the pedal. There's only the pivot mount @ the firewall & then the throttle cable passes through into the engine compartment; I don't see anything else electrical.

[hopelessredneck]

driver side of the transmission by the pan

[54Caddy]

thats it man, I will take a few pictures for you tomorrow where my original wire came out, i now have a 700r4 but wire is still there i think. will check in the morning.

[hopelessredneck]

see pic

[hopelessredneck]

sorry pictures are turned to the left taken on iphone lol

[rs72z]

Scoti, is th trans still in the truck? Is the wire long enough to be the one that conects to the trans or is it for sure the one that goes to the switch? I also thought the switch was under the dash.

[SCOTI]

The wire in question was severed so I'm not sure if there was enough length to reach the trans or not. I had the portion exiting the harness/loom & the end piece. When added together, I didn't think the length suggested anywhere but the immediate firewall area.

I'll take a peek underneath @ the trans tonight as I haven't made those connections yet either. I do know the truck has a rebuilt th400 vs the original.

Hopelessredneck, thanks for the pics.

[SCOTI]

This is what triggers the kickdown signal right? There's nothing like this under my dash. Are there other types? Does the ECM possibly control this function on TBI trucks?

[rs72z]

Did it ever work? Maybe a po removed it.

[rs72z]

Another thought, maybe it was controled by the tps through the ecm?

[JCampbell]

As a fellow TBI'er chasing trans issues, I can tell you that there is no kickdown switch located under your dash. TBI trucks are controlled by a kickdown relay that is located on your firewall slightly to the left of center. It's paired up next to the fuel pump relay...they look identical to each other.

[SCOTI]

Originally Posted by JCampbell

As a fellow TBI'er chasing trans issues, I can tell you that there is no kickdown switch located under your dash. TBI trucks are controlled by a kickdown relay that is located on your firewall slightly to the left of center. It's paired up next to the fuel pump relay...they look identical to each other.

Originally Posted by rs72z

Another thought, maybe it was controled by the tps through the ecm?

Ok... These (the relays) are both in place. This was starting to be my thought as well (the ECM controlled the kickdown via TPS & manifold pressure). Sounds logical anyway....