BassMasta808

Hey guys, I'm having a bit of a hard time figure this out after days of researching and parts being replaced. A little history:

About 8 or 9 months ago the car overheated and had a major overhaul on the cooling system and related systems. Parts replaced:

Head gasket (head did not warp)
Water pump
Timing belt
Radiator/cap/hoses/thermostat/thermostat gasket
Vtec solenoid gasket (for good measure)
Valve cover gasket
Heater core flushed


Car drove great around town with no issues after that.

3 weeks ago I went on an 800 mile trip and the car started getting hot about 600 miles in and blew the cap off my reservoir tank, coolant spraying everywhere. Pulled over and removed thermostat (which was locked shut) and was able to make it the rest of the way to my destination. When I arrived I re-replaced the following:

Rad cap
Reservoir tank
Thermostat/thermostat gasket
Cleaned thermostat housing and made sure it wasn't warped.

Now rad fans do not kick on. Replaced:

Fan switch in the thermostat housing

Fans still will not kick on at operating temp. They do, however, run when the AC is on. They do not kick on when ignition switch is turned on like they used to. I haven't tried the relay yet, but if both fans kick on when the AC is on, doesn't that mean the relay is ok?

Heat works. AC works. No lost coolant. No milky oil. No smoking. Doesn't burn a drop of oil from oil change to oil drain. Car is religiously maintained....

2005. 145,000 miles... I'm about to dump her at the dealership for a new Si.

SMS (Save My Seventhgen)

ezone

It never did this. If it did, it's not supposed to.



Turn the key to ON, do not start the engine.
Jumper the 2 wires in the fan temp. switch connector.
Do the fans run?

BassMasta808

Yes they did, I bought the car pretty much new. But idk maybe you're right, now you got me thinking if they did or not. Pretty certain they did cuz I'd hear them. Can you explain how to jump the switch connector? I assume just take a paperclip and stick it in the switch connector?

ezone

They aren't supposed to. If they did, that was wrong.....unless the coolant temp was high enough to run the fans or the AC was on.

Affirmative.

Don't shove it in so hard you spread the connections out though, just touch to make contact with both terminals.

BassMasta808

Ah you're right, maybe it was either cuz of AC on or car temp was up. Ya now that I think about it, they wouldn't come on in the morning on a fresh start.

So please, good sir, give me a "what to do next" if they do or don't come on. If they don't, I assume I need a new connector from the parts store and splice it in there. But what if they do come on?

ezone

If they DO come on, then you just proved out everything electrical except the temp switch.

If they DON'T come on, you have a problem that needs further inspection.

BassMasta808

You mean the coolant temp switch?

God I hope "further inspection" isn't necessary. Those new Si's with the HFP kits and K series are looking nicer each day lol

ezone

Whatever switch was not in the circuit was not tested. Comprende?


Finding and fixing a broken wire (or whatever) sure seems simpler to me than dropping $22,5xx and losing 5k of it the second you drive it off the lot.

BassMasta808

Eh I'm about to get an independent dealers license so I wouldn't be paying retail. I'm just getting mad at it and have spent so much time trying to figure it out yano? I drive way too far and too often to have this fear of breaking down all the time. For me, time is more valuable. A parked car is making me $0. But I really appreciate your help bro. I'll check out your suggestions tomorrow and let you kno if I get this problem identified.

BassMasta808

Jumped fan switch and fans came on.

Source of problem: air in the system. Bled it all out, filled it all back up. Fans kick on, car stays cool. All is right with the world.

Thanks dood!

ezone

Aaaaand where did this "air" come from?

BassMasta808

From me taking the thermostat out and then fan switch and not filling the radiator back up sufficiently. I actually took it apart a couple of times because the housing leaked on my 1st attempt. I didn't give it enough time running with the rad cap off to make sure it was full and bubble free. I actually probably didn't even need the fan switch but owell. It all works now. I guess I'll keep the ol **** a while longer