Hi All,

I'm having some strange electrical issues and I've got no idea where to start fixing the problems.
Here is whats happening:
- Put the key into the ignition and turn to the "on" position, full power to everything no issues at this point
- Turn the key to the start position, get 1 click out of the starter and then lose all power to everything
- Turn the key off and back to "on" position, sometimes I get power at this point and sometimes the power stays dead for a while
- Check the battery, which is good (12.3 volts)
- At one point someone noticed some sparks coming from a connector near the back of the firewall on the passenger side (sits on top of a metal cover with a large positive terminal right behind it). I've disconnected this terminal, cleaned it and put on some dielectric grease all of which hasn't done anything.
- Basically I mess around with few things, check some connectors, let it sit for a few minutes and then it will start.

I have no idea where to even begin with this and I'm hoping for some help.

Thanks
Rob

 

Usually a bad battery connection or cable (either end, either cable).

Use conventional voltage drop testing (google it) to pinpoint.

 

When a sparking area was seen, what more do you need to at least look at and be sure those connections are securely tight?.

What happens when there is an intermittent issue?
1. Heavy current draw can 'melt' metal at the poor high resistance connection areas and causes a complete open circuit.
2. That metal being hot and flowing can re connect the circuit again when it flows and cools.
3. This makes it appear the problem is aleviated.
4. The next time high current is attempting to pass that same location it melts open again.
.
Lead connections at battery terminals are very prone to this as well as any other part of a circuit.
There is no mistery, just get in there, check and clean up all areas.
If you don't it will keep coming back to haunt you again.
Good luck.

 

12.3v is essentially half charge (12.6v is fully charged) which explains the clicking on start attempt, as well as the other circuits behaving as you described. The harder it is pulled down, the longer it takes to 'recover' as you've noticed.

As for the sparking, it sound like a short. Probably at the Starter Relay. I rerouted the cables when I built a new fuse block for simpler maintenance. Shorting pulls power away from everything as it is the path of least resistance.

 

Have to disagree with your assessment, Travis. More likely than not, the sparks were the result of trying to pull 100-150 amps through a bad connection and it was arcing in that connection.

Voltage drop testing is still your best bet, but do fully charge the battery first. Trying to pull starting current from a semi-discharged battery is a good way to shorten its life.

 

Excellent point ProjectSHO89, corroded connections are poor conductors and yield poor results. Considering that one terminal on the Starter Firewall Relay as THREE cables on it, it is the most likely failure point. This is a design fault, but easily correctable.

When I redid mine, I eliminated one cable and moved the junction point to my DIY'ed fuse block. The eliminated cable was replaced with a 1/8" thick x 1" wide stainless steel jumper bar that links the battery side of both mega fuses at their studs, similar to stock. Result is one fewer connection and everything is stainless so corrosion won't happen. The block and link bar cost me under $15 to build and will last forever.

The remaining cable from the fuse block to the starter relay can be downsized from 4awg to 12awg as it only supplies power to the Starter's switch terminal. Even though it's not causing issues right now, I should do that sometime just so everything is fresh, clean and new.