proper temp sensor wire routing

[K25alive]

What is the proper routing for the green wire from the temperature sending unit to the temp gauge? Right now my wire runs parallel to the block, then at the last spark plug ducks left in between the block and the exhaust manifold and appears to keep going south, I lose track of it. Is this routing correct? It doesn't seem logical it would pass in between the block and the exhaust manifold. Maybe this is why the gauge doesn't read correctly, the wire has been compromised? The truck is a 1979 K25 with 350ci.

[TrailerTrash]

if you ask me, it should not go between the manifold and engine. neither of my trucks had it like that when i got them but neither of them had the original engine in them either.

it looks like someone took the manifold off at some point and just slapped it back on without watching where the wire went.

i would unhook the wire and try to trace where it goes. it probably goes down to the rear of the engine then back up to the harness at the firewall around the brake booster bracket somewhere. then reroute it safely away from the exhaust manifold. the sending unit or the wire itself could be melted/damaged and causing the gauge to read incorrectly

[TKCR]

Well here's mine. Pic #1, I put a heat sock on mine, there was just not way to keep it off the manifold. From there I routed along the frame & wheel well. I also put it in heat resistant tubing. Pic #2, It then goes back to the firewall and meets up with the engine harness. Pic #3, It goes left under the master power and then through the firewall right behind the fuse box and up to the cluster

[ray_mcavoy]

The factory valve covers had brackets spot welded to the top like on this crate engine:


Plastic clips snapped into those brackets and held the spark plug wires along with the temp sender wire.

So the original temp sender wire routing branched off from the harness at the back of the engine, ran across the top of the driver side valve cover, and then down to the sending unit.

[bhc41051]

My 75 has the wire coming over the valve cover like Ray said.

[Max1775]

Originally Posted by TKCR

Well here's mine. Pic #1, I put a heat sock on mine, there was just not way to keep it off the manifold. From there I routed along the frame & wheel well. I also put it in heat resistant tubing. Pic #2, It then goes back to the firewall and meets up with the engine harness. Pic #3, It goes left under the master power and then through the firewall right behind the fuse box and up to the cluster

That's mighty clean looking. Good job.

[hatzie]

Originally Posted by bhc41051

My 75 has the wire coming over the valve cover like Ray said.

I believe that's the way they were run originally.

[TKCR]

Originally Posted by Max1775

That's mighty clean looking. Good job.

Thanks!! I tried running them along with the spark plug wires, I just hated how it looked, so I improvised.

[K25alive]

Thanks for your input everyone. I'll be sure to figure out a new route for that wire.