some cooling problems

[QWKSNKE]

With the install of the electric fan and dc control my car has been running nice and cool EXCEPT when the a/c is on. Yes the fan is wired to come on with the a/c but when I am in traffic my car runs way to warm. (does fine at 70-80 mph on the interstate, but below that it runs a little warmer than normal)

Also, when the fan is running it is pulling a good bit of the voltage. when the fan is running my oem volt meter is showing between 10-11 volts and when the a/c OR headlights are on it drops down to between 9-10 volts.

My question. Could it be that the electric fan is not operating efficiently or at full cfm because of the low voltage. Curious to know whether I need to upgrade to the 94-up alternator.

[Wicked]

What is the amperage on your alt now? Any car with a electric fan needs the alt to handle it, i.e. 94+.
I would say that 10-11 vs. 13-14 is definitely gonna slow the fan down, maybe even hurt it over time.

What kinda of radiator do you have?
What thermostat? Water pump?

[QWKSNKE]

3 row radiator
180 thermostat
nothing special water pump.

Stock alternator. Somewhere around 100-110 amps I believe.

[Wicked]

I guess its only been running hot since the intercooler/blower install huh?
A fan will suck 30 amps of power. I know mine uses a 50 amp MAXI fuse.

Sounds like the Alternator is your best bet.

[Shorty]

Originally Posted by QWKSNKE

Stock alternator. Somewhere around 100-110 amps I believe.

is the Cobra alternator higher output than the stock GT?

if the voltage is low it shouldnt pull correctly. same as your headlights dimming when you run the stereo wide open.

[QWKSNKE]

Originally Posted by Shorty

is the Cobra alternator higher output than the stock GT?

if the voltage is low it shouldnt pull correctly. same as your headlights dimming when you run the stereo wide open.

I think so but I am not sure.

my lights have always dimmed down when coming to stop.

[Craig K.]

Do you have a larger pulley on the alternator than stock? If you have a smaller pulley, then in the alt. should spin faster at the lower engine RPM's giving you more amperage at idle, and low RPM range.

You could add a bottle of water wetter, that usually is good for a 5 to 10 degree drop.

I believe that the 94+ cars have multi speed cooling fans, is yours?

You could put in a big aluminum radiator, and a good water pump, but then it is more $$$. If you did want to upgrade your water pump I have an Edelbrock that has 1 hour of run time on it that I have in the for sale section.

[86GT]

The stock 86 -93 Mustang including the Cobra has a 65 amp alt. Yes that is wright only 65 amps. I had to also goto a larger alt. I grabed one out of a 95 Taurus along with the wiring. Its a 130 amp. The nice thing was the factory wiring on the Taurus was the exact length needed on the Mustang. I only had to cut one wire, and that was the one going to the dash. It had to be hooked up to the new wiring harness.
http://webpages.charter.net/eecanalyzer/Doc/3G.pdf

[QWKSNKE]

Originally Posted by 86GT

The stock 86 -93 Mustang including the Cobra has a 65 amp alt. Yes that is wright only 65 amps. I had to also goto a larger alt. I grabed one out of a 95 Taurus along with the wiring. Its a 130 amp. The nice thing was the factory wiring on the Taurus was the exact length needed on the Mustang. I only had to cut one wire, and that was the one going to the dash. It had to be hooked up to the new wiring harness.
http://webpages.charter.net/eecanalyzer/Doc/3G.pdf

Definitely time for an upgrade

[86GT]

MOst fox body mustangs had a serious problem with the alt. You could turn on defogger, headlights, AC, and a sterio and watch the battery voltage go below 12 volts.