Electrical Surge when Fan turns on

[S&B]

So I have switched over to running a 75 amp fuse and relay for my fan. That works great car cools wow good.

Now the bad part at idle if the fan turns on it damn near kills the car, i bumped my idle up to 1400rpm but I dont want to go that route. What should I do?

When I had my 40 amp fuse and relay i didn't have this problem, should I go back to running a smaller fuse and relay or is that crazy?

I have a 220amp Pa perforamnace alt Do i need a bigger one?

thanks

 

[jrichker]

A 220 amp alternator is more than enough in most cases.
Working on the assumuption that you have a good 2 gauge or
4 gauge power wire, check the grounds.

The secondary power ground is between the back of the
intake manifold and the driver's side firewall. It is often missing or
loose. It supplies ground for the alternator, A/C compressor
clutch and other electrical accessories such as the gauges.
Any car that has a 3G or high output current alternator needs
a 4 gauge ground wire running from the block to the chassis
ground where the battery pigtail ground connects.
The 3G has a 130 amp capacity, so you wire the power side
with 4 gauge wire. It stands to reason that the ground side
handles just a much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery & extra 3G
alternator ground wire as described above in paragraph 2. A screwdriver
points to the bolt that is the common ground point.
The battery common ground is a 10 gauge pigtail with the computer ground
attached to it.

Picture courtesy timewarped1972

Correct negative battery ground cable.

 

[Darkwriter77]

Good grief, if a 220-amp alt won't cover it, nothing will. Something is definitely amiss. I'm not sure how running a larger relay and fuse would make it act like it has an increased load, but my only guess would be that there's a bad connection issue where it's creating more resistance in the circuit and THAT is what's causing the increased load. Maybe double-check your connections and grounds to see if anything is amiss, and if not that, then it might be something internally within the relay and/or fuse that's adding a lot more resistance.

 

[HISSIN50]

Also ensure your IAC is functional.

I'd go back over your wiring and double check it. Carefully look for any solder or crimp connections that are hotter than a random stretch of wire in an adjacent portion of the circuit. Extra heat indicates a bad connection, which could be partially to blame for the shock on the E-system.

 

[S&B]

Okay I will check these things and feel for heat. I know i have the 4 gauge all around one ground from the batter to a post I made when hiding the wires. I have the battery in the trunk with another ground obviously. I use the ground side of the relay for an onswitch for the fan.
I have a system
big ass fuel pump with a 30amp relay
This fan 95 5.0L fan

 

[1991vert]

mine's good with a 130amp alternator. it definately should not be killing the car