What is this wire?

[Old Guy Bill]

Does the truck have a TH400? or did it originally?
Looks like the trans down shift solenoid wire.

 

[Ricko1966]

Where is your temperature gauge/light sender on this truck?

 

[hypercycle]

im sorry i have no idea regarding which transmission is on my truck; i assume the GM goodwrench 350 long block that replaced the original 400 SB was placed back on the original OEM transmission for 1979 K20 3/4 ton 4x4 Suburban, TH400?

temperature gauge is working fine

thank you

 

[Goldie Driver]

Here is a quick pic to ID - it will either be a 350 or a 400.

Transmission Match: How to Visually Identify an Automatic Transmission - OnAllCylinders

Transmission identification is a common issue among classic car enthusiasts. According to the Summit Racing technical department, it’s one of the most-asked-about topics when customers call for advice. We dedicated an …

www.onallcylinders.com

 

[Old Guy Bill]

im sorry i have no idea regarding which transmission is on my truck; i assume the GM goodwrench 350 long block that replaced the original 400 SB was placed back on the original OEM transmission for 1979 K20 3/4 ton 4x4 Suburban, TH400?

temperature gauge is working fine

thank you

The TH400 has a solenoid wire connection on the drivers side of the transmission. It would be where the white circle is in this pic.
This wire is energized by a switch on the accelerator pedal.
It is light orange on my '78.

 

[JD1973]

LOOKS LIKE WIRE FOR YOUR FUEL GUAGE, MINE IS THE SAME COLOR

 

[Bextreme04]

My 80 K25 has a TH400 and that same bracket with orange wire going down to the kick down. Energized by an electric switch on the gas pedal.

 

[hypercycle]

Do you happen to know where that bracket on the wire would bolt up to for kick down?
im pretty sure now the wire is not for the gas gauge afterall

thank you

 

[Bextreme04]

Do you happen to know where that bracket on the wire would bolt up to for kick down?
im pretty sure now the wire is not for the gas gauge afterall

thank you

It was on one of the bellhousing bolts down the drivers side. The wire runs down behind the drivers side head and is held onto the transmission bell housing with that bracket, then plugs into the connector on the drivers side of the transmission.

 

[kkgp81]

My 78 K30 has the same wire on the firewall that has been broken. TH400 truck.

 

[hypercycle]

thank you Bextreme04 !
i will ck that out once the weather is more favorable