How much amperage does this thing draw?

[rd]

Still messing with the cooling fan. It works with an auxilary relay, but I melted a 30 amp fuse holder Thursday. The fuse did not blow, but the plastic melted all to pieces.

So I put in a 30 cycling circuit breaker from Advance. It works, but the 30 amp relay is very hot to the touch after a 10 minute trip.

I just put 10 ga wire from the bat to the relay and fan, and from the fan to ground at the bat post. It is a new replacement motor.

My inductive ammeter is saying it is drawing 35 + amps! Does this fan need that much current?

 

[JB66]

rd, just so you know, I looked up some of the fuse ratings on some of the other vehicles. A 96 Mustang, for example uses a 60 amp fuse for the cooling fan. A 95 Town car is 30 amp, but does have a built in relay to power it. I guess you need to make sure the fan has the correct motor in it so it draws under the specified fuse rating.

 

[RustBucket]

A bad fan motor can draw more amps than it should normally. If the bearings are bad or the brushes/commutator are worn, it can take more power to produce the same results. Does the fan spin freely? If you spin the blades by hand, does it stop as soon as you let go? It should make a couple of revolutions after you let go.

One other possibility could be dirty or corroded connections at the fan or the relay. Bad connections increase electrical resistance which can translate to increased current draw and heat.

 

[rd]

Thanks. It appears that this fan draws in the 25 to 35 plus range. It has not blown either a 30 amp fuse or tripped the 30 amp circuit breaker yet. But it melted the first plastic fuse holder and makes the 30 amp relay very hot to the touch after a 10 or 15 minute drive.

It is now wired with 10 gage wire direct from the bat to the cb to the relay to the fan, maybe 24 in of wire, and a 20 in 10 ga ground directly to the bat neg post.

Some research online shows that MAD Enterprises recommends two 30 amp relays in parallel to serve a cooling fan, vice one big relay.

Maybe thats why the Ford module has the two relays in there.

Gonna try the two relays in parallel next. If that does not work, I guess I will install a Black Magic fan system.

 

[rd]

Cooling fan update

I am doing it this way so I can drive the car...

I just installed two 30 amp relays in parallel to the fan motor. Used 10 ga wire on all the power connections, but still feeding both relays with one 10 ga from the battery.

It seems better, you can touch the relays after 15 minutes of ac on running and the inside module is much cooler. I will give it a 20-30 mile drive as soon as possible.

The fan puts out an hurricane of airflow, but the amp draw seems to be a problem.

It appears that Ford used 2-40 amp relays in the module, to power the fan with a 12 ga wire. Both the input from the battery and the power to the fan melt the plastic at the module connector. I don't have a wiring diagram on the car that shows the splices and exact ground locations, so I am not sure what is actually in the circuit, but this is more trouble than I have had with anything like this.

Plan C is to replace the fan with a Black Magic system, I guess....

Desperately seeking information and suggestions.