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1990 Chevy K1500 Ground issue?


ryanusrey2012
10-14-2013, 09:38 AM
I have a 90 K1500 and as it has a lift kit on it including body lift so there is an auxillary electric fan instead of mechanical. One day i was driving my battery fell out of place and the plastic got melted off by a heater core hose. Ever since then everything electrical (except the starter) is only working half stat. It is not the battery or the terminal because i replaced them both. I found a broken chassis ground (firewall to frame) and replaced it and it did not fix the problem. My question is, did i replace the wrong ground or put it in the wrong spot or am i supposed to attach the ground from firewall to engine block? this is a 5.7 350 tbi with 227,XXX miles on it.

jdl
10-14-2013, 10:28 AM
With vehicle running, the alternator should supply voltage to electricals. Is the charging system, working?

j cAT
10-14-2013, 02:26 PM
I have a 90 K1500 and as it has a lift kit on it including body lift so there is an auxillary electric fan instead of mechanical. One day i was driving my battery fell out of place and the plastic got melted off by a heater core hose. Ever since then everything electrical (except the starter) is only working half stat. It is not the battery or the terminal because i replaced them both. I found a broken chassis ground (firewall to frame) and replaced it and it did not fix the problem. My question is, did i replace the wrong ground or put it in the wrong spot or am i supposed to attach the ground from firewall to engine block? this is a 5.7 350 tbi with 227,XXX miles on it.

the engine need be grounded to the sheet metal body metal . the battery ground goes to the engine block and the body ground also

Schurkey
10-14-2013, 08:03 PM
the engine need be grounded to the sheet metal body metal . the battery ground goes to the engine block and the body ground also
More accurately, the body needs to be grounded to the engine, which has the main ground cable to the negative post of the battery.

ryanusrey2012
10-15-2013, 08:58 AM
With vehicle running, the alternator should supply voltage to electricals. Is the charging system, working?

yes the charging system does work when running but as i drive down the road everything electrical in the vehicle will be working half stat and will sometimes very briefly flicker back on to full power than go back. This also affects all my gauges

ryanusrey2012
10-15-2013, 09:55 AM
So what you guys are saying is where the ground from the battery runs to the block i need to run another wire from there to the body, not the firewall?

jdl
10-15-2013, 10:41 AM
I've seen faulty battery cable cause flickering. A lot of makes and models have negative battery cable going to alternator bracket.

I've seen the negative battery cable connected to the engine, where it was almost impossible to get at. When replacing the cable, I moved it to the alternator bracket. Everything worked fine and easy to get at.

intermittent issues can be a pain to track.

Schurkey
10-15-2013, 11:01 AM
everything electrical (except the starter) is only working half stat.

everything electrical in the vehicle will be working half stat

1. What, exactly, is "half stat"?

2. I would be looking at the lighter-gauge (perhaps 10 or 8 gauge) cable that is supposed to be part of the main positive battery cable, which supplies power to the distribution system under the plastic cover on the right side of the firewall.

ryanusrey2012
10-15-2013, 02:51 PM
1. What, exactly, is "half stat"?

2. I would be looking at the lighter-gauge (perhaps 10 or 8 gauge) cable that is supposed to be part of the main positive battery cable, which supplies power to the distribution system under the plastic cover on the right side of the firewall.

hmmm before i replaced the terminals i knid of did suspect that positive wire and when i hooked it up i did not exactly ensure that it had good conection ill check that out. And when i said "half stat" i meant exactly that it is all working on low voltage.

aleekat
10-15-2013, 03:55 PM
hmmm before i replaced the terminals i knid of did suspect that positive wire and when i hooked it up i did not exactly ensure that it had good conection ill check that out. And when i said "half stat" i meant exactly that it is all working on low voltage.

Did you replace just the terminals or the entire cables?
Corrosion can be down under the insulation causing all types of current draw issues.

j cAT
10-15-2013, 03:57 PM
I have a 90 K1500 and as it has a lift kit on it including body lift so there is an auxillary electric fan instead of mechanical. One day i was driving my battery fell out of place and the plastic got melted off by a heater core hose. Ever since then everything electrical (except the starter) is only working half stat. It is not the battery or the terminal because i replaced them both. I found a broken chassis ground (firewall to frame) and replaced it and it did not fix the problem. My question is, did i replace the wrong ground or put it in the wrong spot or am i supposed to attach the ground from firewall to engine block? this is a 5.7 350 tbi with 227,XXX miles on it.

lets say you have good cables. clean connections no green colored wire etc /// which I doubt is the case here . then we get into loose fuse sockets and the fuse links that are hidden in the wire loom sometimes.

with your "the battery fell " tells me a lot about this trucks condition and care .

ryanusrey2012
10-16-2013, 07:45 AM
Well I ran a new ground from the top of the engine block to the body and it resolved my problem thank you guys for your input. It is still dropping 60mV across the body ground system but i believe that is acceptable right?

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