Electrical issue

[SabreRaider]

1990 K5 with earlier 350 swap.
Main ground is mounted at exhaust manifold bolt.
Ground arcs to manifold on start-up.
I've had an electrical gremlin where the wipers will rarely cycle once on start-up.
Question is should I just buy a new main ground and relocate? Locate to where (frame, firewall, hood bracket bolt, ?) and see if it solves the issue, or is there a possible larger underlying problem I need to sort out? Bolt on manifold is surface rusted....is it just jumping to header and I should just replace that manifold bolt with a new one for better contact?
I'm really low on electrical knowledge and any help is appreciated.

 

[Bent77]

Yeah sparks are bad, but going to the manifold is worse

Ground wire (negative off battery) should go the the frame next to the engine and another wire off the front of the engine to that same point.

Hang on a minute I’ll snap a picture of mine

 

[Bent77]

This is how mine is routed, it’s a 77 frame with the 89 serp set up

Move that bolt to where mine is on the head. Clean it up real good with sand paper. Try it.
If all that is better add the cable back to the frame later

 

[SabreRaider]

This is how mine is routed, it’s a 77 frame with the 89 serp set up

Move that bolt to where mine is on the head. Clean it up real good with sand paper. Try it.
If all that is better add the cable back to the frame later

View attachment 303153

Thanks much...will do.

This is how it's currently ran.

 

[SabreRaider]

I'm picking up new ground cable and battery clamps tomorrow.

 

[Bent77]

Those might be fine if you scrub the cooties off them

I don’t see that bolt hole on your engine. Find one that cable can reach to. Or one a new cable will reach to if it’s longer

 

[wasted wages]

yeah, that's not good...heat is the enemy of electrical flow, and grounding it to the exhaust manifold is probably the worst possible place it could be connected to.

any 3/8 bolt within reach of the cable, on the head, block, a/c bracket will work..

 

[SabreRaider]

Those might be fine if you scrub the cooties off them

I don’t see that bolt hole on your engine. Find one that cable can reach to. Or one a new cable will reach to if it’s longer

Would it be fine for now to mount ground to frame hole in pic just in front of positive wire bracket bolt and run engine to frame when I find a good spot?
Also, when mounting to frame, better to clean painted surface and bolt on, or wire brush surface spot to metal?

 

[Bent77]

Would it be fine for now to mount ground to frame hole in pic just in front of positive wire bracket bolt and run engine to frame when I find a good spot?
Also, when mounting to frame, better to clean painted surface and bolt on, or wire brush surface spot to metal?

Yes, just clean clean clean.

But we definitely need to get that's ground to the block, especially if it's fuel injection

 

[SabreRaider]

Yes, just clean clean clean.

But we definitely need to get that's ground to the block, especially if it's fuel injection

Carb, but will run both. Thank y'all much for the help.

 

[diesel4me]

GM put the ground cable to the alternator bracket on most vehicles since 1973 or so...its important the alternator has a good ground,to protect the diodes from voltage spikes...there is usually another cable for ground from the frame rail to that bracket or somewhere on the engine block in the front side..

GM also put two braided ground straps from the 2 rear most valve cover bolts to the firewall also,and most had another at the transmission to frame near the bell housing also..

If you have delay wipers,its not uncommon for them to activate whenever they feel like it..my '79 C-10 had them and it had the "ghost wiper" action,they would sometimes come on by themselves any time they felt like it while driving...never did figure out why..several members here report having the same issues..

 

[SabreRaider]

GM put the ground cable to the alternator bracket on most vehicles since 1973 or so...its important the alternator has a good ground,to protect the diodes from voltage spikes...there is usually another cable for ground from the frame rail to that bracket or somewhere on the engine block in the front side..

GM also put two braided ground straps from the 2 rear most valve cover bolts to the firewall also,and most had another at the transmission to frame near the bell housing also..

If you have delay wipers,its not uncommon for them to activate whenever they feel like it..my '79 C-10 had them and it had the "ghost wiper" action,they would sometimes come on by themselves any time they felt like it while driving...never did figure out why..several members here report having the same issues..

Thanks! I'll look around and see what spot looks best and get the right length cables.
Thanks too on the wiper info. Thought I might have had an elec issue with the wipers, but mine are the intermittent. Sounds like its a common issue.

 

[diesel4me]

The wipers on my '79 used to cycle most often when I stepped on the brakes...they also came on one sweep when I turned on the headlamps sometimes..I think the control module gets flaky with age and too sensitive to voltage surges ..or a ground fault maybe..

 

[1-ton]

That ground to the exhaust manifold has to go as fast as possible. The negative battery cable on my truck goes straight from the battery to the engine block.

 

[dyeager535]

Thanks too on the wiper info. Thought I might have had an elec issue with the wipers, but mine are the intermittent. Sounds like its a common issue.

IMO the wiper setup on these trucks is problematic in general. Now that I think about it, unmolested truck, I'd bet someone that the wipers are probably the most failure prone factory item on the truck. Mine don't work properly either. Sometimes they will do the phantom wipe thing, and if I don't turn them to run (not intermittent) then back off, they won't shut off.

 

[SabreRaider]

How about re-running ground to the front hole on empty spot on acc rail under ac compressor? 3/8" bolt/nut?

 

[SabreRaider]

Not gonna try to get the nut off that bolt on header...just gonna cut ground cable close and run new wire.

 

[SabreRaider]

How about re-running ground to the front hole on empty spot on acc rail under ac compressor? 3/8" bolt/nut?

View attachment 303195

If so, then run same location to frame for 2nd?

 

[Wes Harden]

Some one move it to the exhaust bolt when they put that shi##y neg battery clamp on and shortened the cable.
You should have a 4ga(min) ground from battery to unpainted hole on head or intake, a 4 ga jumper from same or similar point on engine to frame, and a10 guage from battery to radiator core support.

 

[SabreRaider]

Some one move it to the exhaust bolt when they put that shi##y neg battery clamp on and shortened the cable.
You should have a 4ga(min) ground from battery to unpainted hole on head or intake, a 4 ga jumper from same or similar point on engine to frame, and a10 guage from battery to radiator core support.

Yepper...think they got in a hurry with swap.
They have the 10ga going to firewall front next to battery.