kishy's 1985 Country Squire

[kishy]

might try soaking those in oil first. Steel in aluminum is bad news though, not a lot to be done for it. I don't suppose that piece can come off the throttle body?

It does not come off, unfortunately. That means drilling the old ones out is quite challenging as it's hard to hold this thing in any particular orientation. It doesn't even sit flat on the mounting plate as the linkage hardware sits lower.

I did use penetrating oil to try to make the trouble one on the second TB come loose, it helped but not enough. I did use heat to try to make it come out, it came free enough to turn enough to give me confidence, then snapped off.

The screws used here seem to be abnormally weak (severely corrosion-weakened, maybe, despite decent appearance). That combined with a relatively fine thread and steel+aluminum is just no good.

I am probably going to oversize the holes and use a modestly larger fastener with a less idiotic head/drive choice.

The car can start and run without high idle, it just means I have the curb idle a little higher than it ought to be and have to start it with the pedal, which I've been doing all along. I just don't like knowing that the reason high idle doesn't work has changed from "a faulty replaceable part" to "a broken lifetime component of the engine" but it doesn't really matter, at the end of the day. I broke things and netted no resulting reduction or gain in functionality.

Gonna try to tackle cruise next. It needs to work. I dislike not having it.

[gadget73]

might try soaking those in oil first. Steel in aluminum is bad news though, not a lot to be done for it. I don't suppose that piece can come off the throttle body?

[kishy]

Decided to fix the idle speed. Had to replace defective choke thermostat thing. Had good one in parts.



$%#@



More where that came from...



$%#@



Going to have to swap the throttle body with whichever one I can get the screws out of cleanly. Will take the chance to re-test the TPS as the idle hunts a bit and this is a characteristic problem.

Can't really self test the car until the idle stuff is worked out, so I'm just troubleshooting on CFI-autopilot.

[gadget73]

Feeding the + off the battery unloads half the circuit at least. Eliminates the drop on all the stuff on the + side of the circuit. No help for the switched negative. Less load on that part though, its only carrying the blower rather than the blower plus all the other garbage on that power feed.

[kishy]

After perusing the EVTM the circuit works like so:

Switched power to the hvac function switch, when in any mode except off, power then flows to the blower motor itself.
On the ground side of the blower motor, the blower resistor (through its highest resistance path) is in parallel with the blower switch, which in the low position is n/c, so current flows through the resistor's full resistance.
Each faster switch setting provides a shortcut to ground at lower resistance values.
The motor therefore ultimately grounds either through the resistor in low speed, or through the resistor then through the switch in medium or high. (and ATC adds further complexity, but it appears it just duplicates the fan speed switch.


Best places to make improvements therefore would be:
-Cleaning terminals at blower motor, switch, resistor
-Add a relay pulling straight from the battery at the positive wire into the blower motor, have it be switched by the original positive wire into the motor. This skips pulling the motor current all the way through the fuse panel and dash wiring.
-Clean or make better grounds where they come from the resistor and blower switch.

There does not seem to be a way to make the in-dash parts no longer switch high current.