Ignition power issues

[BRONCONY]

Hello all,
I haven't been around here for along time but getting in to spring got me working on the bronco again. Finally got everything going right then a old problem from last year returns. No cranking power. Turn key on everything works. Hit the start and the solenoid clicks or buzzes and everything is cut to half power. Turn key off and back on everything is still at half power. Thought the starter was drawing too much so I got a new one and tested it with a jumper off the starter side of the solenoid to the new starter and grounded it to the motor. Same thing. Grounded my battery in a different spot and same thing. The interesting thing is I hooked my air up compressor to the starter side of the solenoid and when keyed to start (cranking position) it works fine. Just normal. I guess maybe a bad ground and something doesn't like the load of the starter. I'm running out of ideas. Lol. Maybe voltage regulator?

 

[Explorer]

I would start with having the battery load tested. Then move to the cables, starting at battery by bypassing each with one half of a jumper cable. They can appear good, but be corroded inside. Starter solenoid you can bypass the same way by jumping across the two large terminals. Just make sure tranny is in neutral or Park if automatic.

 

[BRONCONY]

I would start with having the battery load tested. Then move to the cables, starting at battery by bypassing each with one half of a jumper cable. They can appear good, but be corroded inside. Starter solenoid you can bypass the same way by jumping across the two large terminals. Just make sure tranny is in neutral or Park if automatic.

This is what we did last year. Replaced all of the main cables. One to the starter battery
Ground and positive cable and it went away. But now returned. The battery tested great so I'm going to pick up a new starter solenoid today and return the starter. It's just really confusing cause there's not much to that starting system. When I left the key on and didn't hit start there where some wires that where warm behind the dash but I'm not sure about that. So once it's tripped something takes all the load and keeps it. Even turn the key off and back on everything is half power till you pull cable off the battery. Something just Robs and keeps the load.

 

[Toddpole]

Start simple. Clean all connections. Use a file or wire brush until they are shiny. Be sure you clean the cable and the location it connects to. Clean battery terminals, starter solenoid, starter connection, frame and engine block connections.

 

[BRONCONY]

I have yet to even find a engine to frame ground. Or body to frame ground. Only main ground I can find is the main one from the battery to the block. Should I add these 2 grounds? Also I noticed the battery positive cable and terminal was warm when it's at half power.

 

[BRONCONY]

Not sure what I did but it's fixed for now. New starter solenoid and hours of messing around it's working again. Weird

 

[Viperwolf1]

I have yet to even find a engine to frame ground. Or body to frame ground. Only main ground I can find is the main one from the battery to the block. Should I add these 2 grounds? Also I noticed the battery positive cable and terminal was warm when it's at half power.

You should add an engine to body ground. The factory location was the rear of the intake or head to the firewall. Frame ground isn't really necessary unless you have something that draws a lot of current grounded to it.

The warm spot is where you have a bad connection. Lots of current flowing through too much resistance creates heat.

 

[Steve83]

What do the battery terminals look like?