1987 Coupe, OBDI

My car has been throwing a code the last week, code 15...I think I know what is causing it.

I reengineered my fan setup, I'm running a permacool fan off of the battery, the computer has no knowledge that its there, I'm in charge of turning it on.

I was running my hobbs meter off of the fan circuit. That way, there is power at the fan when the ignition is on. I had a revelation and now the Hobbs is running off of the lighting circuit, that way, I don't get the 15 seconds or so per start that the ignition is on, but the car isn't started. This way, the hobbs doesn't start until I turn on the fog lights, which is third on the list after starting the car...it goes 1. start 2. oil pressure 3. lights.

Anyways, the code was thrown right after I made the wiring change. Now the fan circuit is just open, there is no load on it. I'm wondering if the computer is flipping out because there is no power being drawn through the fan powre wire...

Another thing I just thought of. I just retorqued the heads. In order to get the valve covers off, you have to move the top-end wiring harness. I wonder if I pulled the coolant temp sensor for the computer out...the dash still reads a believable temperature. I'm gonna have to check that.

What else would cause this code? Does the no-load on the fan wire make sense? What should I check?

Thanks. :seeya

 

It's the coolant temp switch in the front of the block under the TB.

 

That was exactly it. :cool: Thanks. I broke that clip off a long time ago, but its been staying pretty well, this was the first time I had a problem and it was because I was pulling on the wiring harness to get it out of the way.

The clip fell up behind the water pump pully, I was very lucky that it didn't get munched. :eek:

:seeya