Why wont my car ground properly?

[dave_s1987]

Hey guys, just thought I would see if someone can help me out. I have been having a lot of trouble getting my new motor to finally start up. When I was finally ready to start it I could not seem to get any power to the starter. I checked all connections and was receiving good voltage to all areas. The previous owner had a battery relocation kit in the trunk so I checked the ground connection at the frame and cleaned it up and sealed it but it did not make a difference. Then I checked the instructions and it said to run 10 feet or more of positive wire you would need 00 gauge wire (very thick) and he only had about 14 feet of 4 gauge. So today I put the battery Back under the hood and ran a much shorter 2 gauge wire for the positive and the negative. It did not make any difference at all. Still get all power to the lights and good voltage but it won't engage the starter at all. When I remove the ground from the frame and ground it to the on the starter it engages and works great. I've tried cleaning up 4 difference spot on the frame and rad support but it does not make any difference. I don't have a long enough negative cable to run to the motor but the block is grounded to the frame already anyways.

What I am doing wrong here? It's getting very frustrating trying to get this worked out, so any insight on what I need to do would be more than greatly appreciated.

Dave

 

[dave_s1987]

Should I just make a larger ground cable and ground it under one of the bolts that mounts the starter to the block maybe?

 

[Texas82GP]

Paint could be your problem. If you are running custom battery cables anyway, then run a ground from the battery to the frame. Run a ground from the frame to the engine (the same 2 gauge wire). Be sure you have a good ground strap from the engine to the firewall. Also, a moderate gauge ground (say 8 or 10 gauge) from the negative side of the battery to the fender is a good idea.

 

[Ribbedroof]

You didn't say how you were energizing it when you grounded directly to the starter, so I'll ask this:
Did you check to see if the purple start wire is sending a signal to the solenoid when ignition switch is in crank ?

Also, more info on starter/solenoid/relay in use would be helpful to help troubleshoot.

 

[motorheadmike]

Paint, powercoat, rust, corrosion, pixie sh*t... these things are going to bugger up your connections. You need to ensure that all the mating surfaces for the starter (on the starter, and the block mounting pad) are free of contaminants. Put some dielectric grease in there too. Then run a BIG cable from a clean lug on the block to a clean spot on the frame - don't assume that the threads of the bolts are going to be able to carry the current you are asking for to drive a loaded electric motor.

I run double grounding cables to both side of my engine block to both frame rails in the wagon - the shortest distance to ground is your friend (at least as I understand it).

 

[Matthew Goeke]

i would use some sandpaper and clean all grounds and the bolts,nuts that hold them down, and make sure all connections are very tight. also id make sure your battery still has alot of charge, i know it sounds like a simple mistake but alot of people make that mistake.

 

[dave_s1987]

Thanks for the tips so far guys. The starter I am running is a power master 3hp mini starter. It's overkill for what I need but I got a deal on it lol

When I tested the ground on the starter mount I was energizing it with the car battery still. I just pulled all the wiring up so I could test it all as it would normally be in the car. I got tired of installing the starter to the block to find out it wouldn't work so I'm doing it this way so I know it will work before I re install it.

As of now I am running the battery ground straight to the frame. I have taken the frame to bare metal to ensure a good connection. The only ground I have to the actually motor is a 10 gauge wire going from a clean bare metal spot on my block to the same spot on the frame where the battery is grounded. I am assuming this might be my source of trouble? Maybe i should run the battery ground to the same spot where I have the 10 gauge wire on the block instead of to the frame then? And then maybe run a 10 gauge wire from my block to both sides of the frame instead of one?

And yes I did check the ignition wire at the starter as well and it gets full voltage when the I try to turn the motor over.

Also does it have to be grounded to the actually block or can I ground it to a cylinder head or intake? Only reason I ask is because the spot where the ground is now is hard to get at.

Thanks again for your help so far. It's always appreciated!

Dave

 

[dave_s1987]

i would use some sandpaper and clean all grounds and the bolts,nuts that hold them down, and make sure all connections are very tight. also id make sure your battery still has alot of charge, i know it sounds like a simple mistake but alot of people make that mistake.

Thanks for the tip!

Every ground connection I made was to absolute bare metal so far. (Maybe not enough of them though)

I thought it might be the battery too but it engages fine as long as I touch the ground wire to the starter mount when cranking. i also took the battery out of the equation and hooked it up to my booster pack with the exact same results. It would only engage when I clamped the negative to the starter mount.

Dave

 

[pontiacgp]

I laugh when I read some instructions tell you that over 10 feet you need 00 gauge wire. BMW have been using 4 gauge wire from the battery in the trunk to the starter in the engine compartment for years. I have the battery in my trunk and use 4 gauge wire to the remote solenoid and 4 gauge wire from the solenoid to the starter. When you use a household 240 extension do they use a heavier gauge the longer the extension is?

 

[Matthew Goeke]

Thanks for the tip!

Every ground connection I made was to absolute bare metal so far. (Maybe not enough of them though)

I thought it might be the battery too but it engages fine as long as I touch the ground wire to the starter mount when cranking. i also took the battery out of the equation and hooked it up to my booster pack with the exact same results. It would only engage when I clamped the negative to the starter mount.

Dave

maybe the starter is bad? i would take it out and test it, it could be alot of things like maybe even your ignition switch