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TylerS10 11-13-2013 06:32 AM

MSD Hiccup with fan switch.
I'm kind of at a loss here with this annoying glitch. I went through the trouble of installing a 140 amp alternator over my 100amp. Added up all the amps in my system and came up with 65 amps total with everything on at the same time. Headlights both fuel pumps and so onÖ
My fans are wired to two 60 amp switches that are manually activated so I can cool the motor off in the staging lanes. My water pump is also wired in the same manner with 12 gauge wires. Grounds are directly to the fame.
MSD is wired independently from an aftermarket fuse box in the cab with 12 gauge wires and a ground going to the frame and battery just to be safe.
Here is my problem I have noticed if I turn the fans off and then on or the water pump while the motor is running I can see the MSD light flash off for a quick millisecond and the motor will hiccup slightly. I have never noticed this till I had to purchase my MSD Digital 6Al since my old MSD 6Al died.
Faulty MDS box?.... Or will a high voltage capacitor for the MDS resolve the issue? Iím guessing the voltage regulator canít keep up with the start load from the electric motors.

TylerS10 11-13-2013 07:04 AM


Originally Posted by Denny (Post 1908738)
((Iím guessing the voltage regulator canít keep up with the start load from the electric motors.))

Sounds more like a voltage drop. The load should be off the battery, thus the battery amperage. Do you have the loads separate, and not drawing from the same line ? Are the chassis grounds, also grounded good to the engine block ? Eng, Frame, Chassis.

The MSD and fans have their own lines off the battery. I did get lazy on the water pump its coming off the charge line from the alternator. ( My be my problem right there )

The grounds are actually a bolt welded to the frame with a nut on top to lock down the ground wires.

Iím going to rerun the alternator charge cable back to the battery and move my water pump to its own line also hopefully that will do the trick.

TylerS10 11-15-2013 02:34 PM

Ok, so I replaced a lot of wires rendering my electrical system NEW. Everything seemed to be in order 14 volts while running no problems. Then the problem came back again and it died at a light like a switch turned the Truck off. It was at that moment a light bulb appeared above me head. ( The kill switch!) Yep my 10 year old kill switch was acting up I could jiggle the switch and the MSD fired up.

I felt like a tard and was happy at the same time to finally track down the problem. Easy fix... in the end =)

EOD Guy 11-15-2013 03:53 PM

Been there done that

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