I did a very stupid thing a few months back and removed the logicon from my 86 GXL. That in itself may not be stupid, but deciding to simply cut the harness as opposed to pulling off the dash was. So with winter coming, and North Texas seemingly turning into a temperate rain forest as of late; I need some help...

I'd like to wire up a switch that would do two things:

1- put the heater blowing on high
2- defrost the front windshield

No more, no less. I can live without heat in the car, but not being able to see out the window when it fogs due to rain and temps is no fun

I tried looking at the wiring diagram for the logicon and heater motor operation to no avail..... I have no problem splicing into the necessary wires and soldering, but for reading diagrams I am useless.... which wires to where?

I'm asking a lot I know, and short of repairing the entire cut harness and extending the wires and simply re-locating the logicon, this seems like a cleaner solution.

Thanks!

 

So during class today Im gonna take a good long hard look at the wiring diagram again and see what I can do. Sunday if i have time I will hopefully post up some results...

 

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Ah ha.... I see, well I may just reconnect the cut harness (ugh....) and relocate the logicon then; it seems that it is going to be almost impossible for me to find the wires needed to do what i want to do...

 

yeah, sorry for the other post, i realized it wasnt important after i re read your post. i did look thru some of the wiring diagrams, but i cant make sense out of them either. :/

 

o, you can see if hailers knows anything about this, from what i read he knows the fc electrical system very well.

 

Yea, Im kinda waiting for him to chime in, lol.... but relocating the thing would make things a lot easier and more convenient in the long run...

 

yeah most definitely, you could put it in the glove box or under a single din radio.

 

Glove box is where im gonna go, or maybe attached under the dash in the pass footwell....ill post pics when im done sunday.... if i can finish, lol...

 

my heater/blower assembly is about to become a yard ornament.

 

I am in a similar situation where all I needed is defrost. On my car I am not sure if it's the logicon or the motors.

This is what I did. The airmix motor (left side of dash) controls the coolant flow into the heater core, I disconnected the rod from the motor and wired it in the hot position (lever pulled down).

Next was to get the air flowing to the defroster. I pulled the rod off the lever for the mode control motor. The FC uses 3 doors\flaps to direct the air flow. The top door is for the vents, the middle door is for defrost and the lower door is for heat. I don't remember which way I moved each door, I just kept trying different combination's until the air was coming out of the defrost.

As for the blower motor, my logicon still run's that sometimes (I am planning on using a resistor assembly and fan switch from a Miata when I get the time to do it). There are 2 relays that need to energize to get the blower motor to run. the HEATER relay and the EX-Hi relay check this thread for more info on the relays.

You may want to add some way of controlling the amount of coolant flow to the heater core, I live in Michigan and found that leaving it set to full hot, was unbearable at times. I used a piece of bicycle brake cable, and some zip ties so I could adjust it.

 

Hell yea, thanks for the info. This wouldn't be that hard after all...