Dekorum

This problem has been going on for a long time and I haven't found the complete solution. First off, I have a 1992 Civic hatch with a B18C Type R motor. I have a Flex-A-Lite fan that used to work very well, for the first year or so if I can remember.

The problem is after driving for a while, and then being stuck in traffic my car will start to overheat because the radiator fan turns off or never turned on. There has also been a few times when the radiator fan will stay on after my car is turned completely off. I have made different threads here when I have had those various problems and thought I found fixes. So far, I replaced the cooling fan relay and it seemed to fix things for a while. It was burnt on the top right corner and it burnt the fuse box itself a little. The fan has not come on during the past road trip I took and I had to pull over once traffic hit. Today, I replaced both the ECT sensor under the distributor and the ECT switch (fan switch) on the thermostat housing. I just drove for 20 minutes and once I had to slow down in a parking lot to find a parking spot, the car started over heating again and I realized the fan still refuses to kick on. I took out the relay (bought it new OEM a few months ago) and it is burnt in the SAME SPOT. When I put it back in, the fan kicked on for a little bit but turned off soon after.

Any ideas? I can't figure out what would cause the fan relay to keep blowing or burning up like that. The 15A fuse near it also looks a little burnt on the metal that connects the two ends, but it does not appear cracked so I think its still working. Once a few years ago, the fan connector burned up a little and Flex-A-Lite sent me a new fan motor with new wiring and a new connector because it had cracked. I was never sure about the reason for that, but the pigtail from the engine harness that connects to the fan connector got a little burnt back then too but it seems to be fine. The fan motor wiring had frayed a little but because I kept it tucked near the radiator support between the chassis and the coolant reservoir so I think the motor shorted after it somehow grounded itself through moving around while driving.

Could my stupid PnP HIDs be responsible for all of this? I would go back to halogens if I knew for sure that this problem would disappear.

Dekorum

Or is the overpriced FAL my problem?

axis11

Get an ammeter and check how much current is the fan drawing.If it is more than the wire and connectors can handle, surely it will heat up and burn things.

calteg

Better yet, anyone know how to hard wire the radiator fan to the ignition? I have a similar problem, replaced the relay and everything on the thermostat, still occasionally overheats at low speeds.

axis11

Find the cause of overheating and fix it.

Dekorum

I will try to check this in the next few weeks. I am very busy now, but I would not like to think that my FAL fan is the root of the problem. Anyway, do you know how much current the wire and connectors can handle?

I don't really want to know this though. Please search or make your own thread to find out how to do this. I would like everything to be working in factory order.

civicguy395

the switch on the thermostat houseing unplug that cut the plug off and tie the wires together fan will run all the time and come on with the key same thing i did with my car only thing is the heater wont work as well in the winter is only downfall wont throw a check light either

Dekorum

I guess you didn't read that it is a problem most likely having to do with my fan relay. I installed a brand new ECT switch on the thermostat housing and it did nothing to my problem. I now find out that I wasted money buying that part because I think mine was fine. Jumping the connector or using my switch results in the same thing, the fan only comes on for a short amount of time when removing and reinserting the relay.

civicguy395

if i was u id bypass the relay all together power the fan from a switch in the cab like old skool hot roders do its only 2 wires a hot and ground

civicguy395

either way if ur burning up relays and such id say the problem is in the wireing itself being either 2 small or the fan is drawing 2 much current which could mean the fan needs replaced

Dekorum

The wiring is stock. Therefore it can't be too small. I haven't ALWAYS had this problem. I am not going to power the fan from a switch. I want it to work like factory, like I already said. I am going to check how much current the fan is drawing by the end of the week. The specs for FAL fans say that should draw 9.5 A. I just don't want to believe my fan motor is drawing too much current out of no where, since I do not want to have to buy a new fan. I am looking for any other input on this situation, whether or not it sounds like it could be caused by something else. If I did get a new fan, I am leaning away from another FAL but I can't use the factory fan because the shroud interferes with my Kidd Racing RMF header.

civicguy395

a bad ground could cause this also like maybe the ground isnt getting a good connection and making the relay get hot because its having to force more current from the higher resistance at the ground making the relay get hot and burn out

civicguy395

sometimes wires develop resistance as they age and oxidize like old battery cables might look into this aswell

Dekorum

All of my grounds look fine. Not sure how else to check those.

axis11

Try spraying electrical contact cleaner. Your connectors might be having some corrosion causing it loose contact and heat up. You were burning connection points on the relay and fuse, right? My connectors for the radiator fan burned a few years back due to build up of dirt.

Dekorum

Yeah the burning is on the relay and the fuse. Spray electrical contact cleaner where? My actual fan connector is new and the female connector that it goes into as well, I replaced it 2 years ago when it burned up. I wonder if it forever tarnished the wires.

Dekorum

Any other ideas? I believe there is a short somewhere in the cooling fan circuit. After searching through some more threads on here, I noticed some potentially useful information about a yellow wire from the ignition to the underdash fuse box being a part of the problem. So the underhood fuse box cooling fan relay and cooling fan fuse (15A) are definitely burnt. The relay is burnt horribly in the upper right pin. I believe that only a short could cause this much current and burning. I have powered the fan motor alone with 12V and measured that it draws 10A so I don't believe that the fan motor itself is bad and draws double the current that I saw at certain times. Its just not really probable.

The cooling fan fuse (7.5A) in the underdash fuse box is not blown or burnt. I do not know where to look for a short. I need some help... I know that occasionally I will have a completely NO start situation, where the car will not even try to turn over or make any noise when I turn the key. This usually would happen after the fan would stop working and my car would overheat, then I would turn it off and try to restart it in traffic. This sounds like my issue could possibly be linked to an ignition problem? Maybe I have a bad ground somewhere, but I don't know where or how to check. All of my engine grounds, including the one near the ECT switch LOOKS fine.

Dekorum

I would really like to figure out how to fix this within the next week or so, before I go on a 5 hour road trip. I have a new relay and fuse for the cooling fan in the underhood fuse box but I am reluctant to put them in because I have a feeling they will burn up after a few days, although it may fix the cooling fan for a while? I am about to buy a used underhood fuse box off ebay because the socket for my cooling fan relay is pretty burnt and it could be causing another short, in addition to one that I might already have which caused this to burn...

Dekorum

The new relay and fuse lasted for about a month. Today, the cooling fan relay burned up again, pin C melted and it's destroying the plastic around the fusebox socket. I still have no clues on what to do.

Dekorum

I went to the junkyard to get some fan relays from other 92-95 Civics. I didn't notice ONE SINGLE one that had burnt/melted plastic in the fuse box under the fan relay. How am I having such a rare problem?

dazebreak

Without looking at the Helms right now, I will go off what you wrote in your post.

You said the fan circuit has a 7.5A fuse, yet the fan draws 10A ? The fuse should be blowing. This doesn't seem right.

One thing I have noticed when working with electronics is if a pin or wire or connector gets a short and burns, then the resistance is higher from that point on until you replace or otherwise fix the problem. The burned pieces could have hurt what they plug into. In other words, how do the contacts where the relay inserts look? Clean? Too much resistance makes the circuit have too high of a load. You need to replace or clean the contacts. How are your wires on the circuit? If you unplug connectors to isolate the circuit from the battery, then check with a meter to frame ground you can hopefully make sure the wire isn't grounding out.

Have you looked at the wiring diagram and taken into consideration all components and wires? Are they all sound in insulation, low in electrical resistance for the gauge of wire, and don't smell burnt? Again isolate wiring from the battery voltage, check resistance with a meter.

Yeah, just re-read your last post... I think you need a fuse box, but you need to replace ALL damage as a SET. Make sure nothing else is the problem and make sure that circuit can handle the current you are putting through it with that fan! A fuse blows at 7.5A for a reason.

dazebreak

Oh, and one last thing. If in fact that circuit is a 7.5A max circuit as indicated by the fuse, you can't draw over 7.5A without issue. This means a fan that draws 10A will cause huge problems, as you already know. If the specification of the fan is below the fuse rating, and it draws more than rated, your fan motor windings could have a short.

Dekorum

The fuse is 15A. The 7.5A fuse is the one in the underdash fuse box. There are two cooling fan fuses. I believe the one under the dash is for the ignition switch part of the circuit, that one has never blown. The 15A fuse in the engine bay fuse box has not blown again either. But the relays keep burning in the same spot. I understand what you are saying about the connections, so today I tried to clean them well with electrical contact cleaner, as well as make sure the shape of the spade connectors is nice and tight so it makes a good contact with the relay. I thought that was going to fix it, but then the relay got really hot again, to the touch. It never melted, but it must have stopped working somehow because the fan won't switch back on again.

grumblemarc

iTrader: (4)

Don't understand. if the aftermarket fan is causing the issue why have we not tried replacing the STOCK fan to see if you have the same problem?

Dekorum

The flex-a-lite fan is not causing the issue. I have tested it and it pulls a constant 10A, as it should. Also, I do not have a stock fan and can not use a stock fan because the shroud will hit my kidd racing header which is why I bought this flex-a-lite one to begin with over 2 years ago.