overcharging? overheating

[jprather]

not sure where to post this, so .. here's the problem.. 1971 RR 383

car was overheating in town, but fine on hwy.. so installed 2 electric puller fans. temp fine in town now ( had to remove clutch fan due to lack of room ) once this was done, the alternator would not keep up with fans.. soooo. installed 100 amp alternator.. ran 6 ga wire to batt, and hooked up other wires as they were before.. now.. car overheats on hwy.. 60 or above..and acts like it is overcharging.. turn signal unit now emits a loud buzzing noise above about 2700 rpms ( hwy speed ) when using turn signals .. what the h*ll is going on ??

 

[OH71RRunner]

Did you install a fan controller for the fans? If the fans aren't set up right, they can act as a generator putting current BACK into your electrical system.

I was using an electric fan for a while. I had to install a diode to ground out the over current from the fan.

 

[jprather]

they hard wired to key switch.. on all the time..its not my car, my buddies..

 

[OH71RRunner]

I think the issue is with the fans being on when they aren't needed. I don't think you'd need the fans on at highway speeds, especially when you say there was no issue. Maybe run a toggle or pick up a fan controller, or a relay or two.

Hopefully, somebody with more electrical knowledge will chime in.

 

[jprather]

seems to be more RPM related than speed.. does it no matter the speed, just at high rpms.. does that make sense ?

 

[black64]

Fans should be contolled by a fan controller or relays and a temp switch. Does the vehicle have fan shroud? Are you still running the mechanical fan with the electric fans? As for the buzzing when turn signal on could indicate high voltage causing the flasher to cycle fast. Do you have anyway of checking voltage when this happens?

 

[jprather]

car does not have clutch fan, just the 2 puller fans, they have their own shroud, no relays

 

[black64]

Since you only have the electric fans I would test the system by temporarily adding a relay to shut fans off at highway speed to see effects on cooling. Is alternator grounded to the engine? Is the alternator internal regulated? Reason I'm asking it sounds like your overvoltage and the regulator is not contolling voltage on your buzzing noise with turn signal on. only way is to add volt gauge and monitor at higher rpm.

 

[jprather]

it is routed through the factory voltage regulator, think i will have him install a temp toggle on fans .. see if it stops

 

[jprather]

how would any of this account for over heating at 60 + mph now ??

 

[PurpleBeeper]

how would any of this account for over heating at 60 + mph now ??

I don't know your electrical issue's solution, but I have been down this same road on my car. With electric fans (either 1 big puller, 2 small pushers OR 1 big puller + 2 small pushers) I would be fine around town BUT would overheat on the highway. I figured that at higher speed, the fans were actually blocking enough of the radiator to make the car overheat (not enough air flow past the fins since many of the fins were blocked by fan).... ran cool in traffic though. I ended up going to an el-cheapo aluminum 4-core radiator + fan shroud & new clutch fan (factory style) and my overheating problems, both in town & highway, went away.

 

[rlem1977]

Always best to consult the manufacturer's directions for application and installation. You could very well have the wrong product and have it connected wrong.

 

[Yatzee]

not sure where to post this, so .. here's the problem.. 1971 RR 383

car was overheating in town, but fine on hwy.. so installed 2 electric puller fans. temp fine in town now ( had to remove clutch fan due to lack of room ) once this was done, the alternator would not keep up with fans.. soooo. installed 100 amp alternator.. ran 6 ga wire to batt, and hooked up other wires as they were before.. now.. car overheats on hwy.. 60 or above..and acts like it is overcharging.. turn signal unit now emits a loud buzzing noise above about 2700 rpms ( hwy speed ) when using turn signals .. what the h*ll is going on ??

I doubt that the original voltage regulator is capable of handling 100 amp alternator and that the voltage and amperage output is all over the map. Probably why the fans aren't constant at a given rpm. I'm sure that the fans are not damaged but running them off the ignition switch is asking for a major overload on the ignition switch. Basically what the voltage regulator is seeing in voltage required and what the alternator is putting out is inconsistent. Your flasher is cycling super fast between flashes so the internal bi-metal can't cool down.

 

[stage3]

car does not have clutch fan, just the 2 puller fans, they have their own shroud, no relays

I had the same issue with 2 lower cfm puller fans mounted on there own shroud..temps would raise just cruising along at 45 mph! took the shroud off and no more issue's while driving it..the aluminum shroud would not let enough air thru the radiator.and yes it had those 4 little rubber flaps that were supposed to do that..nice pretty unit, but didn't work worth a darn...

 

[WileE]

I don't know your electrical issue's solution, but I have been down this same road on my car. With electric fans (either 1 big puller, 2 small pushers OR 1 big puller + 2 small pushers) I would be fine around town BUT would overheat on the highway. I figured that at higher speed, the fans were actually blocking enough of the radiator to make the car overheat (not enough air flow past the fins since many of the fins were blocked by fan).... ran cool in traffic though. I ended up going to an el-cheapo aluminum 4-core radiator + fan shroud & new clutch fan (factory style) and my overheating problems, both in town & highway, went away.

Bingo.

 

[WileE]

Did you do anything to determine the cause of the overheating ? Or did you just throw the electric fans on ?

 

[67 coronet]

1) put some relays on those fans. short that out and you will be very sorry.
2) check to see if voltage is properly regulated at 2800 rpm or so. could be overcharging bad. just check voltage at bat with eng at rpm.
3) i have always run my fans on a switch. lets me control them the way i want.

 

[Ranger16]

car was overheating in town, but fine on hwy.

What thermostat & fan configuration where you running when this began?
My 383 was running on the hot side when I first got it. I changed the factory recommended 190 stat to a 180 and added a shroud to the direct drive OEM 7 blade fan. No problems since.

 

[black64]

how would any of this account for over heating at 60 + mph now ??

From your opening post all this was done do to overheating in town and the electric fans fixed that but created all the other issues. So was the overheating in town lack of air flow because of a bad clutch fan or no shroud? Seems air flow was the original issue so fix that issue and get rid of the alt and electric fans you would be better off.

 

[jprather]

like i said not my car, it had a 35 amp alt, and a 4 core ( I think ) alum rad with NO shroud and mech fan. overheated in traffic, slow speeds, so he put on the twin puller fans, but they draw too much and alt could not keep up.