battery draw

[stutrac]

ok here is my on going issue when i put my blower motor on the battery discharges in the red if i let the truck run it goes dead in 10 min if i turn it off it goes back to 14v(charging) the truck runs fine for a hr. i replaced battery,alt,new belt, so is it a bad blower motor or blower motor resister :mad: :mad:

[Oizarod115]

ok here is my on going issue when i put my blower motor on the battery discharges in the red if i let the truck run it goes dead in 10 min if i turn it off it goes back to 14v(charging) the truck runs fine for a hr. i replaced battery,alt,new belt, so is it a bad blower motor or blower motor resister :mad: :mad:

 

OUCH! thats alot to replace...

 

most autoparts chain stores will test the alternator and battery for you in house.

 

you should be able to test the resistor... someone will know.

[stutrac]

this the 2nd alt in less then a year the draw is only when blower fan in on if i leave fan off the truck runs fine i have checked all connections grounds,fuse's,belt tension, wires,fusebox,light connectors,

[Eagle]

I think you need to find one of those clamp-on meters that can measure the amperage in the circuit while the fan motor is running. I'd check it at all speeds, too. I don't think there's any resistor at the highest speed setting. Either your fan motor (or a resistor) is adding WAAAY too much load, or the alternator isn't putting out as much as it's supposed to.

 

What do you mean by "discharges in the red"? If you have gauges, they put numbers on them for a reason. What's the voltage? Even if you have gauges instead of idiot lights, though, they aren't especially accurate. I'd also suggest a quick test with a standard multi-meter, reading voltage at the battery terminals. Check it with the engine idling and NO accessories turned on. Then check it with the fan turned on, at each of the three speeds. Assuming this confirms your observations on the dash cluster (voltage below 13 volts with fan running), then turn off the fam and run some other accessories to build up some load and see what that does to the voltage. Maybe turn on the headlights (on high beam, that draws more) and the flashers, and the radio and the interior lights. Check the voltage at the battery again. If the other accessories also drop the voltage way down, it means the problem is the alternator rather than the fan or the resistor pack.

[stutrac]

thank you , i have a clamp on battery load tester i have it running it read's ok(charging) when light's on it also reads ok(charging) with fan on high speed it drops in the red and slowly drops in the dischard area :cheers:

[Frankensteinsmj]

one thing you might try is unplugging the elec connector at the fan and run jumper wires to the battery/fan motor and check your volt meter. that might (not really sure) tell you if you have a short in your wiring. Someone might be able to tell you how to determine how to use the volt meter to determine the amount of amps your fan motor is drawing also.

[Eagle]

I think you should take the alternator out of the truck and have it bench tested. The fact it's new doesn't mean diddly. I put a NEW (not rebuilt) alternator in my '88 and it was totally dead. I made the drone at the parts store bench test the replacement before I walked out the door with it.

[deziped]

R & Rthe blower motor with one from the junk yard. It's shot. :popcorn:

[mj88]

I'm going to agree pull the alt and have it checked. i put in three before i got a good one. if it is bad and you need a new one have them test it before you leave the store.