Calderone

Hi im sitting on the drivers seat of my 87 and its annoying
i put the key in the ON position and the coolant fan starts !
it didnt do this before,migth be related to my AC Delete ???
im checking the connections but everything seems right
help ! im trying to communicate with my engine via aldl with no luck as well,thanks !

0Paul Ruggeri

Sounds like your ECM is in limp home mode. Was anything done to the car prior to this issue?

Lemme

This happened to me when I was first playing around with the aldl cable. To reset it I had to actually start the engine and then turn it off again. After that it was OK.

Calderone

Yes that sounds like it ...reasons ...not sure...

Removed Drivers's side head sensor wiring, fan still work
Removed passengers side head sensor , same thing
i even removed the MAT to see what happened and same thing
i pulled the fan's plug and that obviously make it stop but no sensors are wrong as far as i know its something else ...

i Did a big upgrade but im not sure if the other day the fana was On all the time as well
like five days ago i tried to hook my ALDL cable to datalog with no luck.
im still trying today and no luck.

I installed the Moates adaptor with a new .bin file sent by gregg
but this was happening with the stock chip as well and 2 days ago.

Calderone

I had started the engine many times
i even have a battery kill switch,so the ECM is always de-energized

rodj

Sammy ;
you haven't been paying attention in class over all these years.
Drv side is a mech switch for Aux fan , pass side is sensor for temp gauge
The ECM is the only thing that turns your main fan on

Did you jumper the A/c pressure switch plug?
Switch goes open when the A/c on so if plug is just hanging in there ECM thinks A/c is running and turns fan on as soon as key turned on

Calderone

its hanging !!! i will check it right away

Lemme

Make sure the aldl cable switch position is in the 10K mode. This means a 10 kilo ohm resistor is across the 2 relevant alcl terminals. I have the moates apu1 and the switch is on that rather than the cable.

Calderone

No luck, i made a bridge with a little clip on the front AC connector,fan still works,then i tried with the other connectors hanging in the back
no luck ...

Calderone

Its there,the problem happens when the ALDL cable is off and away...i just put the Key on and same thing...fan is on !

Lemme

There are 2 pressure switches on the line. The one involved in turning the fan on is the one near cylinder 6 closest to the firewall on the passenger side.

Calderone

Guys, i just found a video of the first start and i noticed that the fan was running !
So , i can discard the chip or the aldl tryout. Its something else,im sure one of the upgrades or maybe i did use a clip to bridge the compressor connector and i did the same with another two connectors near the firewall,that were AC related,is one of those the A/c pressure switch plug ???

Calderone

pictures ? i think this might be related to this A/C thing since i deleted everything A/C
and i left the connectors hanging.

Lemme

I just measured the switch and yes it is shorted when "Off" as Rodj says. The connector is a little black round one with 2 sockets. It is opposite cylinder 6 on the wheel side of the engine bay (not at firewall)

Lemme

Ignore this. I was looking at the schematic for the AC pressure cycling switch.

Calderone

thanks Lemme,i think its the tiny one , right?
im sure i tried it , this is the one ?

Calderone

what if i take the old tube that i removed and plug everything back just to try

Lemme

That looks like it. It should be oval shaped not round as I said above. The big round one is the high pressure lockout switch I think which is mounted right next to the AC fan switch

Calderone

Hi Lemme,here i have the long tube where the connectors go attached,i will get this connected tomorrow and see if the fan stops,we'll see, i really hope im not in limp mode :!!!

Lemme

You should be able to just put each end of a paperclip in the two sockets on the small connector to test it out.