Voltage drop under load
Thread Starter
Joined: Mar 2003
Posts: 1,224
Likes: 2
From: Hamilton Ontario
Voltage drop under load Car is at the tuners, can't tune wot because not enough voltage to push the fuel pump. Car was fine a year ago, I switched to a truck alt for the extra amperage since then. Car is fine at idle and light load, it delivers 13 volts but under load it drops to 11.
The car has a racetronics pump that had the hot lead installed but Im not sure if that is still in place. Lots of new exhaust work since the install. The car is a couple of hours away and no hoist in the shop so it makes it hard to try different things.
Any help of opinions would be great. I guess the first thing to try is getting the alt taken out and checked.
The car has a racetronics pump that had the hot lead installed but Im not sure if that is still in place. Lots of new exhaust work since the install. The car is a couple of hours away and no hoist in the shop so it makes it hard to try different things.
Any help of opinions would be great. I guess the first thing to try is getting the alt taken out and checked.
TECH Addict
Joined: Jun 2009
Posts: 2,012
Likes: 0
From: Tulsa, OK
Yup, testing the alt is step one. A bit of math will tell you if the truck alt is doing anything for you. If you don't have electrical loads totaling over 105 amp, then you're getting nothing from it, and wasted money on it. You normally wouldn't have that kind of load without a pretty serious stereo being involved. My bet is you have a bad diode.
Thread Starter
Joined: Mar 2003
Posts: 1,224
Likes: 2
From: Hamilton Ontario
Maybe a stupid answer but what is the Big 3 upgrade. I bought the alt new using the part number for a SUV. I did the swap myself and just plugged in the new alternator never thinking I had to do anything else.
check out the Innovative Wiring Big 3 wiring kit for the F-body.. its literally plug and play.
That said, this is something you need to resolve but I doubt it will solve all of your issue.
