Electric fans burning out the fuses

[hauss]

Posible internal short on motor windings cheap chinesse motor

[Michael C Henry]

The fans are not really large and all 4 together cover the copper radiator. I bought a rebuilt alternator that was rated at 74 amps . The normal single belt alternator that would be used on a FE engine in that era. I used to have problems with the heated water rising to the top of the radiator and draining the batteries when parking and not turning off the master battery switch, I installed a Flaming River push in to kill master switch, It is convenient now, twist to engage and bump to off. I installed a yellow top Optima battery. My car came with the smallest 12V battery he could use. I'd forget to turn off the master switch under the dash on the firewall, Not convenient while belted in. expecting to be there only a moment. The hot coolant would rise to the top and turn on the fans which didn't make that much noise and given a little time I would be left with not enough battery to restart the engine also back then with the way the carbs were set up foe Reno it didn't take much to start just the incline of a gas station drive way was enough to roll a little and pop the clutch it would fire and off I'd go. Now it takes a lot more cranking to get it lit now and the weather here is cooler than Reno during Hot August Nights 1999. I usually start with a full battery, I have left home almost out of gas.

[Michael C Henry]

There you go , I didn't know. Sounds like something I thought would happen. Yet another point to look for if and when shopping for replacement cooling fans next time. I have no problem with my fans at this time but they are at least 35 years old. So this experience may be used in the future.

[CHANMADD]

Those little fuses are not good for a high draw like fans, or fuel pumps.....they get hot and eventually fail....Fans and fuel pump should run relays, and have an inline large fuse for the main relay power wire..

[CHANMADD]

Those little fuses are not good for a high draw like fans, or fuel pumps.....they get hot and eventually fail....Fans and fuel pump should run relays, and have an online large fuse .

[BAsque1]

UPDATE On fans issue:
Yesterday I tested the fans isolated from everything, placed the ammeter on line and each fan by itself, the initial amperage was 45-50 amps to kick on at 205o. Checked all connections ground etc and all are fine. Relays are working fine, I replaced the mini fuses for 30 amp circuit breakers. I changed the radiator cap for a brand new one 13lbs as required in the event that the old cap was not venting properly and added Water wetter to the coolant. At this point I am watching and see if it happens again.

[Ron61]

Lou,

I hope that will correct the problem but if it doesn't send me an email and tell me everything that you have done. I had a friend who had a similiar problem and it turned out to be the last thing we suspected and they tested good on every test. It was just pure luck that we found out what it was. Heck, we even ran new temporary wiring to the fans on his car to make sure there was no intermittant short. But I hope this takes care of your problem as things like this can really be annoying.

Ron

[BAsque1]

Originally Posted by Ron61

Lou,

I hope that will correct the problem but if it doesn't send me an email and tell me everything that you have done. I had a friend who had a similiar problem and it turned out to be the last thing we suspected and they tested good on every test. It was just pure luck that we found out what it was. Heck, we even ran new temporary wiring to the fans on his car to make sure there was no intermittant short. But I hope this takes care of your problem as things like this can really be annoying.

Ron

Good morning Ron:
Tks for your quick reply, well I have checked all connections, changed the mini fuses and use mini circuit breakers instead, isolated the fans and checked the amperage with amp meter, the kick on as expected 205o the initial draw was approximately 50 amps and then goes down to 40-45 while running, turn off at 195o all this is normal. the fans are freewheeling do not show binding or hangups. Changed the radiator cap for a new one 13lbs vented, I was unsure of the venting of the previous cap. I did this because i noticed the puke tank side hose collapsing after cooling off but if it was vented this should not happen. So I changed the cap. I added water wetter to the coolant mixture. Check the online fuse of the hose temp sensor for the fans, that is fine. Test run the car (ambient temp 80o) open road remained at 190o, at a light stop went up to 200o all is fine so far. I will stay away from slow city cruising that is murder for these cars. So far this is all I have done.
tks
Lou
PS
Yes it could be very annoying

[ng8264723]

Does he have high amp relays on these fans? I use a relay that is fed from the alternator. Am I wrong here? I mean does this car have a nice big relay?

[BAsque1]

Originally Posted by ng8264723

Does he have high amp relays on these fans? I use a relay that is fed from the alternator. Am I wrong here? I mean does this car have a nice big relay?

Yes both fans are connected to a relay (one for each fan)

[ng8264723]

That what I figured he needs a relay...……….
Add this
https://www.amazon.com/TE-tyco-Curre.../dp/B00OHRZ782
Use fusible links to power it up. Wire directly from the alternator and do not use your fuse panel to power anything except the relay. Overtime it will get worse

[Michael C Henry]

I'd go with circuit breakers on a lot of electrical control points If you can fix or eliminate what ever tripped the breaker you can reset it and get to some place for help. When I first had the car I went to my nephews house and left late. The head light switch burnt out and I went home with the flashers marking the curbing to get home. You burn a fusible link and your done. But you have to find and fix the problem first or a circuit breaker will just l trip again. and circuit breakers do get tired and used up if used at or near their limit much.

[ng8264723]

How big are the relays? The relay should not blow the fuse. What is the fan power source for the relay?

[ng8264723]

Check this out. There is load on that wire. It does not make sense it should just be turning on a relay.

[Dwight]

Yes both fans are connected to a relay (one for each fan)

If you have two fans and a relay for each then you should have two fuses, one for each relay. Correct?

[ng8264723]

Well it depends what they pull amp wise. But two is better. I like the one relay set up with the volvo system above. I have used a single 75 amp Bosch relay to power a Mark VIII fan. They work well. I have hooked them up to a mech. switch or a temp switch. Both work well.

[BAsque1]

UPDATE ON THE CAUSE
After much digging it all came down to the hose that holds the thermostatic switch for the fans( top hose) it was a contraption ready to literally blow with two hose components totally collapsed due to the weight of the design of this contraption. a brand new hose is being professionally made and hopefully this situation is corrected.

[cycleguy55]

Originally Posted by BAsque1

UPDATE ON THE CAUSE
After much digging it all came down to the hose that holds the thermostatic switch for the fans( top hose) it was a contraption ready to literally blow with two hose components totally collapsed due to the weight of the design of this contraption. a brand new hose is being professionally made and hopefully this situation is corrected.

IMO, the top / outlet hose is not the ideal place for the sensor / switch. That will switch on fans based upon the coolant temperature leaving the engine. Others may disagree, but my view is the best place for the sensor is in the bottom hose / return to the water pump and engine. That way you're measuring the return coolant temperature, and if vehicle movement provides enough airflow and cooling the fans won't come on. A second choice would be a probe that goes into radiator fins.

Once downside of the bottom hose location is you may need a different sensor / switch if the one you have isn't adjustable. You may want to switch on fans at a lower temperature if you're reading it from the water pump inlet temperature / lower hose.

[strictlypersonl]

Originally Posted by cycleguy55

IMO,...
the best place for the sensor is in the bottom hose / return to the water pump and engine. That way you're measuring the return coolant temperature, and if vehicle movement provides enough airflow and cooling the fans won't come on. A second choice would be a probe that goes into radiator fins.

Once downside of the bottom hose location is you may need a different sensor / switch if the one you have isn't adjustable. You may want to switch on fans at a lower temperature if you're reading it from the water pump inlet temperature / lower hose.

ERA uses the bottom hose method. The thermo-switch is pretty low, at 75C, but the fan seldom comes on except when the car is stationary.

[CompClassics]

I would agree with cycleguy55, install a aircraft type breaker switch (toggle type). I was having a similar problem with a clients car. At start up or if he blipped the throttle the current surge would blow the cooling fan fuse, not good if you are stuck in traffic and you have to get to the side of the road to change the fuse. We installed the aircraft type circuit breaker and it’s worked out well. If the breaker blows all you have to do is cycle the toggle switch to restart the fan, You don’t have to pull off the road to change a fuse either.