Alternator Question
Thread Starter
Racer
Joined: Mar 2008
Posts: 487
Likes: 48
From: Ocala Florida
Alternator Question
I just completed an entire front suspension rebuild along with a serpentine conversion, DeWitt aluminum radiator with dual Spall fans. I also included a new 140 amp alternator to help with the additional demands.
Problem is that when I am driving and the fans kick on the alternator gauge on the dash swings over to +40. I thought it might be a ground problem so I ran a dedicated ground wire from the block-to-frame ground and hooked the fan ground wires to that but nothing changed.
Any ideas why it does this and what the solution might be? I'm assuming it isn't supposed to do this.
Thanks
Barry
Problem is that when I am driving and the fans kick on the alternator gauge on the dash swings over to +40. I thought it might be a ground problem so I ran a dedicated ground wire from the block-to-frame ground and hooked the fan ground wires to that but nothing changed.
Any ideas why it does this and what the solution might be? I'm assuming it isn't supposed to do this.
Thanks
Barry
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Sounds like you did not hook the main power feed wire to the alternator directly and ran it off the Battery stud on the starter....that is incorrect install, no matter who says what.....
Thread Starter
Racer
Joined: Mar 2008
Posts: 487
Likes: 48
From: Ocala Florida
Yea I did run it off the starter. Mainly because there seemed to be a lot of guys that did that and didn't seem to have any problem. Wonder why it would work for some and not others?
I'll have to move it and see if that works better.
Thanks
I'll have to move it and see if that works better.
Thanks
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
the FAN POWER is hooked directly to the alternator.....so you have TWO power sources to that relay.....on switched to the coil, the other to the FAN power is always hot, but when ignition is off the relay opens and you have NO drain from the fans.....
Thread Starter
Racer
Joined: Mar 2008
Posts: 487
Likes: 48
From: Ocala Florida
MrVette, you were correct! I hooked up a new wire from the alternator to feed the fans and drove it around today for about an hour and the gauge stayed in place like normal and they heat gauge never got above 180. Still not sure why one works and the other didn't but, thanks anyway.
Barry
Barry
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
It will work either way. Hooking it up as you did 1st runs all the current for the new fans through your existing wire harness, thats why it shows up on the ammeter. The existing harness is Not designed to carry that load. Hooking it on the alternator bypasses the existing harness and the ammeter, so you get no gauge indication that the fans kick on.
Good that you moved it, something would have burned if you had not.
Good that you moved it, something would have burned if you had not.
