Headlights flicker and radio cuts out when driving over a bump

[Jgonick]

My thought- those are the lines that deliver power/current to everything. Battery & alternator (& junction block) are connected there. Headlights draw a lot of current so if the wires are bad they can't supply enough continual current. - this is an over simplification, but you get the point.

Also- if the problem immediately started after putting the starter in- that would be the first place to start looking.

 

[Ricko1966]

I just changed my starter,cut and spliced 2 wires, now my headlights don't work right. Maybe you should check the tire pressure. If I bought new shoes and then my feet hurt, I would suspect something was up with my new shoes, not blood pressure, or brittle bone disease. You need to go redo your starter install and wire repairs before you inspect anything else. After you experiment everywhere its just as possible you are going to create a second problem then diagnostics can get real interesting.

 

[PhotonFanatic]

During all my hunting for electrical gremlins, I saw that the ground strap on the back of the passenger side head was broken. Ordered a new one and installed it yesterday. Now the headlights are working right and the radio no longer cuts out over bumps.

Any other ground straps? Anyone got the master list of all the ground wires?

Still gonna replace those old fusible links near the starter, cause their connections look pretty bad. Found some NOS ones on ebay:

2 NOS FUSIBLE LINKS! GM GMC TRUCK SILVERADO SIERRA C10 S10 JIMMY 1500 2500 3500 | eBay

These help stop electrical issues that can cause great harm to the wiring system if there is an electrical short. This Fusible Link Pigtail is exactly like having a fuse inside the wire! A real life saver if/when a problem occurs!

www.ebay.com

Not exactly the plastic cylinders but they'll do.

 

[Ricko1966]

Post 8. The big 3 are battery to engine battery to frame battery to body. Those are your big three,and if grounding the head to the firewall fixed anything 1 of those three is missing or failed.

 

[Ricko1966]

battery cable there is only one wire on the positive post. It goes to the starter. So if this cable is attached to nothing but the starter than nothing besides the starter will work. Electrical power for everything else in the truck connects to this cable at the starter