UPDATE and ABOUT TO LOSE IT! Electric fan conversion keeps blowing fuses - '01 LS V6

[bamaguy]

UPDATE - PLEASE SEE LAST POST AT BOTTOM

My fiancee has an '01 v6 LS. After many overheating problems and doing ALL the fixes, I installed an electric fan. It has been blowing fuses since I first installed in a few months ago - at first, once in a while, now almost immediately. When it blows the fuse and she doesn't notice, it overheats and sprays coolant all over - possibly on the wiring.

Initially, it would burn up wire connectors, before a fuse would blow - I believe they may have gotten wet when degassing after the coolant re-fill. The car would run fine for several days, maybe even a week before this would happen. I re-wrapped all of them, then one of the 25 amp fuses would blow. When I changed that fuse with a 30 amp, the other blew. The aftermarket cooling fan harness I bought from O'Reilley's has two 25 amp fuses - don't know if they are in parallel or series. That relay was complicated with temp sensor circuit and AC compressor circuit.

I re-wired all of it today with a simple 4-pin 30 amp relay to check everything and it blows a 25 amp fuse instantly. When I switched to a 30 amp fuse it didn't blow after about a minute, but it was starting to smell like it was burning. I have ground direct to chassis, a full-time hot 12v from an open spade in the fuse box, and a 12v switched power source that give power then the key is turned on.

Any ideas?

 

[joegr]

...Any ideas?

Yes, a few.
First, you have some coolant leaks! No mater how much the engine overheats, it should never "sprays coolant all over." Overheating will cause the coolant to boil and cause excessive pressure. If the system is good (no leaks) that excessive pressure will cause venting of steam and coolant through the pressure relief valve in the degas bottle cap. Coolant should pour down by the bottle, not spray everywhere.

Second, the underhood fuse box does not have heavy enough wiring running to it to support the high load of a 30+ amp fan. You need to wire the fan power to the B terminal on the starter or to the power stud behind the front passenger wheel that the starter cable attaches to. The overloaded circuit to the fuse box will cause the voltage to drop. Low voltage may cause the fan motor to draw too much current because the motor can't correctly start up and reach speed.

Third, you may (probably) have other problems with your wiring and your fan. You do have the fan blowing in the correct direction don't you? (Blowing towards the engine, not towards the grill.)

Fourth, rewiring so that it runs all the time the engine is on (I assume this is how you simplified it) will certainly kill the alternator before long.

Fifth, any loose or poor connections will cause a voltage drop and heating. If any are close to the fuse, they will cause the element inside to melt. Anywhere the wiring heats up, is a big problem that needs to be corrected.

 

[bamaguy]

Thank you for your response, Joegr.

First, I will have to look for leaks, again. I have done ALL of the major repairs/upgrades on the cooling system and ultimately found a leak in the passenger side radiator tank, and so replaced the radiator - a MAJOR headache.

Second, good to know that info. I found a constant on power source, but didn't check the wire gauge. This could be the problem by itself.

Third, the fan is reversible, so I have it pulling air through the radiator and blowing at the motor. This, btw, is reversed compared to how it comes wired, so I guess they have it originally wired to mount on the forward side of the radiator. Odd.

Fourth, did not know that either. Will have to wire in a thermostat again.

Fifth, I've checked all connections numerous times. I do have both the relay ground and the fan ground connected to the same chassis bolt. Is this acceptable?

Follow-up question: Is 12g wire heavy enough to run from the starter post to the fan relay?

Thank you again for your help.

 

[bamaguy]

Fan still blowing fuses (!!!! argghhhh!!), but only with motor running. See above for backgrouns, but it's a new electric fan.

I connected the relay power line to the positive battery post lug in the passenger wheel well as joegr suggested. One wire, 12 gauge in a loom. I placed a 30 amp fused break in between that wire and the relay.

I re-mounted the fan ground wire and the relay ground wire together to a better chassis ground.

Re-ran the other wires (one to the fan power side from the relay, and one to 12v switched power coming in) to make sure. The 12v switched power is in the engine compartment and it gets juice as soon as the key is turned to accessory. I will change that later, but I wanted to test this.

When I turn the key on, but not the engine itself, the fan comes on fine. Now, unlike before, the wires seem to stay cool and they don't heat up. So, that's good.

When I go ahead and start the engine, the fuse blows. So I installed a switch in-line of my 12v accessory power access to the relay. I kept the switch off and turned the key to accessory. Fan stays off and the fuse does not blow. I leave the key on and turn the switch on, but not the engine - the fan comes on, fuse does not blow, and the wires stay cool to the touch.

OK, so that's good. So then I turned the new switch to the off position and started the engine. The fan stayed off, and the fuse did not blow. Great. So then I flipped the switch to the on position while the engine was running and the fuse blows instantly.

ARRRGGGGGHHHH!!!! WTF????

Surely 30 amps is enough of a fuse, especially when it works fine when the engine is off. For some reason, it is getting a power surge while the engine is running.

I'm really at a loss here. Anybody have any suggestions??? Please.

PS - I noticed that the first electric fan conversion harness I bought at O'Reilley's had one 25 amp fuse before the relay (on the full power side) and one 25 amp fuse after the relay on the way to the fan. If I'm not mistaken, that's still have a max 25 amp fuse, just two of them, right?

 

[joegr]

So, what is this fan? Do you have a model number or a good data sheet on it? Somewhere, it should say how much current it needs. It certainly could be above 30A. The factory gen II fan is 60A.

Note that with the engine off, you are running from the battery. It could be as high as 12.6V, but may be as low as 11.something under load. With the engine running, the alternator can bring the voltage as high as 14.5 volts. This higher voltage will cause a higher starting current, and depending on the actual rating of your fan, may explain your results.

 

[bamaguy]

So, what is this fan? Do you have a model number or a good data sheet on it? Somewhere, it should say how much current it needs. It certainly could be above 30A. The factory gen II fan is 60A.

Note that with the engine off, you are running from the battery. It could be as high as 12.6V, but may be as low as 11.something under load. With the engine running, the alternator can bring the voltage as high as 14.5 volts. This higher voltage will cause a higher starting current, and depending on the actual rating of your fan, may explain your results.

Don't have the box anymore. The instruction sheet doesn't mention a make or model (I believe it is a Hayden - cheap brand at O'Reilley's), however it does specify a 25 amp fuse.

I'm beginning to wonder now if the fan motor is damaged somehow. The current wiring set-up should work fine. The fan motor has gotten wet with coolant during degassing before - more than once. I wonder if that's damaged something.

Also, when I re-read the instructions, I noticed that to reverse the fan, you have to flip over the actual fan blade assembly as well as the wiring polarity. I didn't flip the fan over. Don't know if that would make that much difference.

 

[LS4me]

The fan motor has gotten wet with coolant during degassing before - more than once. I wonder if that's damaged something.

Also, when I re-read the instructions, I noticed that to reverse the fan, you have to flip over the actual fan blade assembly as well as the wiring polarity. I didn't flip the fan over. Don't know if that would make that much difference.

Hmmmmm..... An electric device got wet and now blows fuses???

You didn't wire it correctly in the first place?????

You seem to have answered your own question.

 

[R34SklnNsn]

Not having the fan blade flipped around you will not get the proper air flow. It may even cause enough drag on the electric motor to make it pull higher amps blowing the fuse and even melting wires.

 

[hite337]

Buy a Flex-A-Lite 183 electric fan around $250. 18 amps max draw. I have used several with zero issues. The oldest one is going on 5 years now in a 2000 LS.

 

[bamaguy]

Sounds like I need to get a new fan.

In everyone's opinion, is the wiring now acceptible (for the new fan)?
- 12v constant on; positive remote battery lug in passenger front wheel well connected thru a 30 amp fuse to relay input (spade #30).
- 12v switched on; connected to an accessory 12v source with a switch now to turn it on and then to the relay (spade #86).
- Fan and relay grounded together on the actual chassis with the paint stripped (spade #85 on the relay).
- relay output wire (spade #87) directly to fan power.

 

[1LoudLS]

wiring sounds fine to me.

you really do need to get a controller for the fan instead of just turning it on and off manually...