420A 99 Eclipse GS OEM fans?

[Dipwhittle]

Probably a dumb question, but I’m having overheating issues because my radiator fan isn’t kicking on. I’m currently troubleshooting this, but also everything I find has two fans on the radiator… my 99 Eclipse GS only has one… and I don’t see the grey/black wiring everyone mentions for the passenger side one. Is that normal? Should I have a second one?

 

[BLACK'98DSM]

Are you missing the driver side fan? Does your car have A/C? That driver side fan is the A/C fan, and only powers on when the A/C compressor engages. It's common for people to delete that when they delete the A/C, though I'd recommend running jumper wires from the passenger side fan and leaving it in place. If your passenger side fan is missing, you need to find a replacement ASAP.

 

[Dipwhittle]

Are you missing the driver side fan? Does your car have A/C? That driver side fan is the A/C fan, and only powers on when the A/C compressor engages. It's common for people to delete that when they delete the A/C, though I'd recommend running jumper wires from the passenger side fan and leaving it in place. If your passenger side fan is missing, you need to find a replacement ASAP.

Amazing, . It is my passenger side that’s missing. That makes a lot of sense, but there doesn’t even seem to be wiring or shroud/mounting brackets… I know very little about cooling, like there’s a tiny metal tube at the bottom of my radiator that I’m pretty sure is also supposed to be connected somewhere too, but it’s not…

FYI, I haven’t run this car more than like 10 minutes at a time since I finally got it running a few months ago. Mostly just for while I’m troubleshooting other things.

Post in thread 'Radiator fans: which fan is which?'
https://www.dsmtuners.com/threads/radiator-fans-which-fan-is-which.470064/post-153339487
Yes on a 420a the driver side fan is the main and passengers side is for the ac.

Mine is a 420A. Are you sure the passenger side is the main? There’s a ton of conflicting posts that both agree and disagree with you, and I can’t find it in any manual. Just need to know if I’m concentrating on the right fan.

To answer your other question, I don’t know if it has A/C, since I’ve never driven it and know very little about the cooling system. It starts, but I don’t like to keep it on since it overheats really quickly and the fan doesn’t kick on.

I know the fan not coming on is at least part of the reason it overheats. I also know it works when it gets direct power. I’m currently troubleshooting why it’s not getting the signal when the engine is hot as f***. I’m thinking the cooolant temp sensor, but I have to check wiring to and from that still…

 

[BLACK'98DSM]

For 97-99 models, the passenger side fan is the primary fan. If you unplug the coolant temp sensor the ECU will enter a safe mode and run the fan constantly. That's a good way to test fan functionality. Don't run the car this way though as it will also run rich constantly.

I was essentially asking if the car still had AC components installed, curious if a full AC delete had been performed.

That metal tube is likely a transmission cooler fitting for auto cars.

 

[Dipwhittle]

I started it up with the coolant temperature sensor unplugged like you said, and the ds fan kicked right on. I guess that IS my cooling fan, and my fan not coming on is because of that..? That fan is the thicker one of the two that people generally have, if that makes a difference.

Can you tell me whether the cables for the passenger fan would have come out at the top or bottom and whether they’re hooked up to a different fuse/relay? My ds fan is hooked to the connector blue/black wires that run straight to the fan relay. I've seen posts talking about a connector with grey/black wires, but I don't see where those would come from. The other fan relays don't seem to be active. I double checked for my sanity. I do have a condenser and compressor, so if they did an A/C delete, they weren't very thorough, ... I would imagine those are the heaviest components and the fan is the lightest.

Also, is this one of those situations where it's a good idea to do some other maintenance? I guess I could change my coolant at the same time. Anything else?

 

[Dipwhittle]

Ok, sorry. Takes me forever to get time to work on the car. Too many kids… anyways, I replaced the ECT, and it didn’t help. The fan doesn’t kick on at temperature, but it does when it’s unplugged… I can’t let it run for very long at all, because it gets hot and sounds and smells like shit. Thoughts?

 

[BLACK'98DSM]

Sounds like the coolant temperature sensor is not functioning. The larger one. The 420A has two sensors on the thermostat housing. The smaller one is only for gauge reading. The larger one controls fan operation and fuel loop. Hence why the gauge is reading but the fan is not receiving power. The engine will overheat in a matter of minutes with no fan operation.

 

[Dipwhittle]

I replaced both

 

[Dipwhittle]

I just ran it for a while. It ran like shit the whole time, especially when it got hot. My temp gun clocked the headers at 400F. Also, the upper rad hose was extremely hot, but the fan never kicked on. My gauge inside never got to half, even though it was hot. Like I said, I just replaced both sensors.

 

[BLACK'98DSM]

That's normal temperature for the exhaust header, in fact it can reach much higher temps under load. It seems like the thermostat is not opening.

 

[Dipwhittle]

Even if the upper radiator hose gets hot?

 

[pauleyman]

Even if the upper radiator hose gets hot?

Define hot. Coolant temps at 200F are very normal. You aren't going to want to touch it. A metal radiator can and will burn you on contact. Plastic will take a sec. Rubber radiator hose will burn you very quickly but not instantly.

 

[BLACK'98DSM]

I just read back through and see that you're still missing the primary fan.

 

[Dipwhittle]

Yeah, the primary fan is definitely the driver’s side on mine. I don’t have condenser fan, but I have the main one. It has never come on without being directly connected. I think that’s either because it’s not getting to temperature and my gauge was wrong or there is an electrical issue somewhere.

I got a new rad cap and am in the process of flushing my coolant. I found rust in it. I also used a bore scope to look at the thermostat, it’s pretty rusty too, but it does open. I think it might be old and worn out. I’m going to replace it and see what that does since they’re cheap and I’m changing the coolant anyways.

First flush, my radiator fluid was dark green and a test strip said it was acidic, which probably wasn’t helping. I’m not sure if all of that is because of the rust or not.

After I emptied that and put in distilled water, it was running a lot better. Still not great though. It was idling at about 800 RPMs and would surge to 2000, then sputter down to like 500 and back up to 800. That happened about once every two minutes or so. I replaced my IAC beforehand, because at first, it was just roaring open at like 4000 RPMs nonstop. With this new smaller surge, I thought it was the tps, but it ohms out at 5000 Ohms and slowly goes down to almost 500 when it’s full throttle. The book is vague on the open throttle ohms. Instead I checked that against a brand new one, and it’s the same (although they could both be bad).

It was also putting out a decent amount of white smoke while it was running, which I know is usually antifreeze or other contaminants in the oil… I didn’t check it for a head gasket leak yet, but that’s coming up when I’m done with this flush. Unless you can do both at the same time? Not sure if it would read the same with just distilled water in it or not. Let me know if you guys think of anything else.

I know this is a lot This thing has a lot of issues, so I have multiple problems causing the same issues that I slowly fix incrementally…

 

[BLACK'98DSM]

I don't have any electrical diagrams for non A/C cars, but for the factory equipped A/C cars the passenger side fan has always been the primary fan. I don't see why they would switch it up. What evidence do you have to prove that the driver side fan is intended to be your primary fan?

 

[Dipwhittle]

I don't have any electrical diagrams for non A/C cars, but for the factory equipped A/C cars the passenger side fan has always been the primary fan. I don't see why they would switch it up. What evidence do you have to prove that the driver side fan is intended to be your primary fan?

In the Factory Electrical Manual, A33 (DS) is the radiator fan and A39 (PS) is the condenser fan. It’s swapped in all non turbos. The driver’s side one also kicks on when you remove the connection to the ECT sensor. I’ve replaced the ECT, so that’s not the problem, but only the rad fan does that to my knowledge.

Mine isn’t a non A/C model. I haven’t asked him, but my brother added headers when he owned it. I assume he didn’t like how close they were to the fan and he took it out. The condenser and everything are still in there. The whole set up is on the passenger side.