LazyLemming

After taking a couple weeks (I'm slow, and didn't have alot of free time.) I finally finished installing my new timing cover seals (And other things). Car runs freaking great and with the BeCool Rad, new waterpump and 160 thermostat, it never tops 165 degrees.

My fans however have stopped working. Normally they are both on whenever the ignition is in "Run" but now they never turn on. Car will overheat at idle and cool right down soon as I start moving. Both fans are plugged in, red wire runs up to a relay next to (NOT IN) the fuse/relay box. Red wire then goes from relay to the positive battery terminal. Black wire goes to ground bolt on frame.

Fans were left under my car port for a couple weeks, so they might be bad, but I'd like to get other theories before I try replacing them. Gonna pick up my multimeter from work tomorow to test there's power over the wires.

Edit: just had a thought. Pressure washed the block while working on it. Covered the relay box when I did it, but this relay was outside of it... Maybe I hosed the relay?

Injuneer

Apparently is does "top" 165 degrees.

You are indicating your fans ran all the time before. Unless you had tha A/C or defroster on, that was incorrect. They should only run when the temperature exceeds 226*F (low speed) and then switch to high speed at 235*F.

There are three relays for the fans. Check the wiring against Shoebox's diagram. Yours is "late" production:

http://shbox.com/1/1995_pcm6.jpg

Guest47904

Too many questions to help you without some answers.

First, why would your fans have been running all the time before you did this work?

It never goes above 165* and it over heats??????????? Fred had this question also.

You mention a relay OUTSIDE of the U/H electrical box. Unless I'm a moron, there wasn't originally a relay outside the U/H box. So this must have been added at some point in time? Yes or no? And would this have accounted for why the fans ran continuously?

If you have a relay outside the U/H box, are the ones inside the box still there? Are they connected to the fans? Is the one outside the box powering both fans? That wouldn't be smart since GM felt it nec. to use 3 relays. Although one is for speed control.

Not sure why we should come up with a "theory". Both relays and fans are easily tested BEFORE YOU REPLACE THEM. Not sure with the information or lack there of, we could come up with a theory anyway.

How about this for a theory. With the fans running all the time, you might never get to the approximate minimum 140*(I'm not sure anyone knows the exact minimum) to get into closed loop. The actual minimum could be higher. Just a theory. Ever give that any thought?

LazyLemming

Sorry let me elaborate...

As long as the vehicle is in motion, it won't top 165. Did a 20 mile drive down some back roads with no stop signs or traffic lights. The car ran at 165 the entire time, even under heavy throttle. It's only when stopped and idling that it begins to heat up.

I know that normally the fans only kick on at specific temps, however there are numerous mods done to this car before I purchased. By several different owners even. I have dubbed it the frankencar. For example, I ran into a previous owner at the tire shop, learned that the tranny is supposedly rebuilt "for racing" with an aftermarket torque converter. Haven't been able to verify this, or get any more specifics, so I left it out of my sig for now.

Before I worked on it, both fans were always on if the ignition was set to "run" no matter the temp. I'm assuming that the relay outside of the box was added by a previous owner to achieve the "always on" status of the fans. I'm guessing this was done to help with the cooling issues caused by the ****ty radiator it used to have.

After I worked on it this time however, the fans do not come on. Ever. Let it idle to 230, neither fan kicked on but my coolant was hot as hell.

I'm not sure what you mean by this. The fans were running before and always ran, no matter the temperature. Now that I have reinstalled them, they don't turn on ever, again no matter the temperature. Both temp sensors will regularly top 140 (The temp shown on an OBD-II scanner is the water pump temp sensor, not the head sensor, right?)

Yeah I checked this before asking, mine is totally different. Both fans are spliced onto a single pair of red and black wires, that lead up to a relay outside of the box. Coming out of the relay is a red wire leading to the positive off the battery, a black wire going to a ground bolt on the frame, and a blue wire that clips onto a wire leading to the relay box.

I understand that since it's not wired like normal, it makes it more difficult for you guys to help. I'm not looking for a "Just do this" kind of answer, but there are plenty of things I miss or don't think of, so I was checking if you guys could think of anything else I should look at as a potential problem. I really miss my car, and only get a little time every couple of days to work on it, so I figured I'd ask during my downtime so I can be prepared next chance I get.

LazyLemming

The relay is fubared. Friend at work helped me out with it real quick. Thanks folks.

Injuneer

I'd still return it to stock. Why would you want to replace the outboard relay, just to keep the fans running all the time? Let the PCM and the thermostat do their job to keep the engine running at the correct temperature.