18 Volts when fan comes on
#1
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Car: 86 Trans Am
Engine: 350 Roch-4bbl
Transmission: 700R4
Axle/Gears: Normal
18 Volts when fan comes on
Hey,
I get a spike in voltage when temp gage reads 225 and fan comes on. I just changed alternator 2 weeks ago, battery is 4 mos old, fan switch is 6 months old.
I have been looking for frayed/loose wires all over the place.
I found a half cooked sparkplu wire and replaced it and I stll get voltage spike.
When I mean spike I mean it stays at 18volts while car is hot.
Everything is normal when car is under 220.
Does any1 have similar Probz?
I get a spike in voltage when temp gage reads 225 and fan comes on. I just changed alternator 2 weeks ago, battery is 4 mos old, fan switch is 6 months old.
I have been looking for frayed/loose wires all over the place.
I found a half cooked sparkplu wire and replaced it and I stll get voltage spike.
When I mean spike I mean it stays at 18volts while car is hot.
Everything is normal when car is under 220.
Does any1 have similar Probz?
#2
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Car: 86 Trans Am
Engine: 350 Roch-4bbl
Transmission: 700R4
Axle/Gears: Normal
Im lookin at gage and when it starts spikin I run to front of car with my FLUKE Multi tester and it reads 20volts.
I pulled off positive cable from battery(car still runnin), battery is 13.9volts
back of alternator is 23 24 volts
I pulled off positive cable from battery(car still runnin), battery is 13.9volts
back of alternator is 23 24 volts
#4
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Car: 1991 Pontiac Trans Am
Engine: 305
Transmission: 700r4
Yikes, that can't possibly be good. Is this the problem you had with the previous alternator? If not, take this one back pronto and ask for a new one. If you get the same problem, that I can't answer. Too much voltage is a bit out of my league.
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Car: '88 GTA,'85 z28
Engine: L98, LB9
Transmission: 700 r4
Axle/Gears: sleepy 3.23, hello 3.73
yeah take it back, it almost sounds like the regulator is in fielded test mode.
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Car: '88 GTA,'85 z28
Engine: L98, LB9
Transmission: 700 r4
Axle/Gears: sleepy 3.23, hello 3.73
ok wait a sec. in re-reading your previous post, you say you had 13.9 accross the battery and 23+ at the positive post of the alt. with the battery disconnected and engine running?
IF so that pretty well explains itself. The voltage regulator thinks the battery is flat dead and tyring to charge it since you opened the circuit. However, I would still think 23 volts is quite high. So that may still explain the problem and the alt. is overcharging when called upon. I say this because I know on mine there is a raise in voltage when the fan kicks to probably about 14.5 volts on the dash meter, that would be concidered normal for the load.
Other than that I would look around for some crumby corroded connections on the fan side. But that would normally cause a blown fuse if amperage were trying to overcome a high resistance in the circuit.
IF so that pretty well explains itself. The voltage regulator thinks the battery is flat dead and tyring to charge it since you opened the circuit. However, I would still think 23 volts is quite high. So that may still explain the problem and the alt. is overcharging when called upon. I say this because I know on mine there is a raise in voltage when the fan kicks to probably about 14.5 volts on the dash meter, that would be concidered normal for the load.
Other than that I would look around for some crumby corroded connections on the fan side. But that would normally cause a blown fuse if amperage were trying to overcome a high resistance in the circuit.
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Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Originally posted by juansupreme
Im lookin at gage and when it starts spikin I run to front of car with my FLUKE Multi tester and it reads 20volts.
I pulled off positive cable from battery(car still runnin), battery is 13.9volts
back of alternator is 23 24 volts
Im lookin at gage and when it starts spikin I run to front of car with my FLUKE Multi tester and it reads 20volts.
I pulled off positive cable from battery(car still runnin), battery is 13.9volts
back of alternator is 23 24 volts
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