Relay turns the fan on and off. Computer sends relay a small voltage signal, relay turns on the fan with a bigger voltage. A thing about the three sensors. One of the three sensors sends a signal to the computer telling it the temp of the coolant. One is used for the guage cluster to tell the driver the temp of the engine. One is used to turn on the fan on and off.

 

Ok, thanks again AgentofDarkness:

I've attached a picture of the temp sensors should anyone else be as confused as I was.

I installed a new rad cap, no luck...

I checked the wiring to that sensor at the bottom of the rad, it's working (just tested with a paperclip so I can't say for sure it's giving the correct read-out.)

While working on my car a neighbor stopped by and said it was definitely my head gasket (ex-car mechanic). Looks like it's time to take it back to Honda to change out the head gasket. (it was only 9 months ago when it was last done so it should still be under warranty, but I still want to figure out why it's gone bad so soon)

Will check back in once I know more.

KS200

[IMG]local://upfiles/15020/33DF3D8F2F43485C8D8AF7E406EB5CED.jpg[/IMG]

 

Hold on, run a compression test before you go off buying head gaskets. If the compression is low in one or more cylinders then you can go have the head gasket. Not insulting your neighbor or anything, but not all mechanics know thier stuff so unless he ran a compression test you can't be 100% sure.

 

Huh... was told twice today that the compression test won't always tell you that the head gasket is blown. (both from the neighbor and from a employee at AutoZone). If I remember correctly Honda tried that 9 months ago and it came back negative.

I'll try to get the compression and combustion leak tester from AutoZone (free rental) tomorrow, if nothing else it will give me more ammo when I take it back to Honda Dealer (old Head gasket still under warranty)

 

I dunno how its possible that a blown head gasket will not loose compression. Since the gasket is blown, it is not sealing properly. THis means that there is a place for gasses to go. Gasses will go where there is least restriction and you will loose compression. But if there is in fact a way a head gasket can blow but still hold compression, i would like to know how that works.

 

Well, here's the scoop... [:@]

compression test positive for leak. I took it to Honda and they said that if they found something defective with their work they'd fix it, but if it's something else it would all be on me (700$ just to replace the gasket... not fixing any other problem). The service guy started talking about a cracked head or block... i.e. engine swap for my car that's maybe worth $2,000.

I'm thinking about replacing the head gasket myself... Time to search the forums before I start asking 10K questions

Thanks again for everyone's help

KS200