Electrical problem after crate motor install

[krcaddis]

All is good after the crate motor installation in my '85, EXCEPT for two wiring snafus.
1) my fuel gauge (dual tanks) is pegged at 3:00. Somewhere under the hood there's an incorrect or missed connection. It's not even supposed to go further than about 1:00.
2) my heater fan and AC controls don't work.

There were a couple of things that had no need to be disconnected by the first mechanic and those were reconnected to match wiring colors. I have no clues what color coding would be for the two items above. But they must pass through the engine compartment. Anyone familiar with those? I've got a Haynes book but the disavow wiring diagrams because there's "so many". The problems shouldn't be behind the dash or anywhere underneath.

I used two mechanics-the first one pulled the engine before Thanksgiving but his family's home burned down in one of the big California fires and he never came back. I finally hired a well experienced mechanic to install the crate motor (I'm disabled) who did a really good job the truck has never run this well. EXCEPT it would be nice to have the heater , fan, and AC working, and the gas gauge of course.

Any help?

 

[RustyPile]

All is good after the crate motor installation in my '85, EXCEPT for two wiring snafus.
1) my fuel gauge (dual tanks) is pegged at 3:00. Somewhere under the hood there's an incorrect or missed connection. It's not even supposed to go further than about 1:00.
2) my heater fan and AC controls don't work.

There were a couple of things that had no need to be disconnected by the first mechanic and those were reconnected to match wiring colors. I have no clues what color coding would be for the two items above. But they must pass through the engine compartment. Anyone familiar with those? I've got a Haynes book but the disavow wiring diagrams because there's "so many". The problems shouldn't be behind the dash or anywhere underneath.

I used two mechanics-the first one pulled the engine before Thanksgiving but his family's home burned down in one of the big California fires and he never came back. I finally hired a well experienced mechanic to install the crate motor (I'm disabled) who did a really good job the truck has never run this well. EXCEPT it would be nice to have the heater , fan, and AC working, and the gas gauge of course.

Any help?

First order of business : Check fuses. Don't just look at them, run a continuity test.. Second step : Check grounds.. One in particular is the braided ground strap connecting the rear of the passenger side engine head to the firewall..

 

[bucket]

On my '79, there's a dual tank harness bulkhead connector on the firewall. If it's left disconnected, the fuel gauge will peg. It might have got knocked loose during the engine swap.

 

[krcaddis]

What does it look like? Can you post a photo?or a link to a drawing?

 

[bucket]

What does it look like? Can you post a photo?or a link to a drawing?

I don't have a picture handy, but it was right behind the driverside valve cover area. It was a rubber body plug pushed into the firewall. Then the frame harness plugs into that.

I just don't know if an '85 would have the same plug in the same place. The dual tank electrical setup changed in the early 80's.

 

[4WDKC]

Check the wire connected to the fan on the passenger side of the firewall under the hood, mine gets knocked off the fan when I set the air cleaner over there. make sure the wire for the aC pressure switches and clutch are connected. Check grounds as mentioned before, gas gauge could be unrelated and just rested connection near the sender under the bed.

 

[krcaddis]

UPDATE:
I checked all fuses=OK
ground from rear of RH head connected to firewall.= OK

found a broken small gauge (20?) loose orange wire at firewall,drivers side, where it appears it was routed through a large flatish plastic clip about 1"x 6" wide that locks closed and also holds holds other wires that are wrapped together w/ E tape, and split loom. One end enters Firewall below-right of Brake Booster along with one heavier (112-10 ga,) green wire Orane goes over Booster then down. Spliced orange wire;no change.

Checked for dual tank wire plug thing at firewall behind head- only thing there is the single orange wire black gooped to and possibly re-entering Firewall. No Joy.

Verified wire to AC connected (light green & dark green). Also wires to heater/fan plugged in. Green & black wires at Compressor connected; clutch doesn't engage when switched on.

For later-[(Drove about 40 miles and heat pegged at 280+.shut it down. Added water once cooled and running. Water pours from LH side below Head, rear of Block above ex. manifold connection to pipe. Had changed all freeze plugs - BUT ONE -that appears to have some kind of safety /temperature indicator w/ red marked thing instead of a normal freeze plug. It must have popped out. (?) Had it towed home, still runs.) All new hoses water pump, belts, 180F T.Stat - no other signs of leak. Will test radiator and cap Newish cap but hard to get off ears to slot. First things first. Rad is AL w/plastic ends;will likely be the culprit - what else is there?)]

 

[krcaddis]

PS. BTW, tranny (th350?) appears to use vacuum for kick-down, not a cable. Is that possible? Or is it a different tranny? Trans code on glove box is MX1 : MERCHANDISED, TRANS, AUTO PROVISIONS
It's a 3 speed, apparently no lock up (?), and won't kick down.