Kain
3/4 ton status
for the tailgate with auto-regulatr there is a switch on the inside that i had bypassed on mine and it caused constant ground, lights stayed on
CK5
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Ok I am losing my mind on this interior lighting
- Thread starter Nutro
- Start date
Nutro
1/2 ton status
Right on. Yeah my dash switch is still there and hooked up and working *Knock on wood
Nutro
1/2 ton status
So I'm not a pro with electrical at all. I took my multimeter out and set it on 2K OHM. I put one lead into the cavity with the white wire on the back of the headlight switch. I put the other lead to the factory ground block on drivers kick panel up high. I got -.051 on the reading. I pulled lead and re stabbed into the cavity again and got .049 and when I pulled headlight switch knob out it dropped to .019
The only thing I remember is this: When I was installing the radio, I needed a ground. I ran it to the ground white coming out of the harness that went to the stock radio. I never could get it to work so I OHMd the ground to the battery and that same factory ground lug was not a good ground. I ended up running a new wire from the battery negative to that factory ground lug and the radio started working. I ended up just leaving that ground wire installed and ran another new wire to the radio by itself for a dedicated ground.
The only thing I remember is this: When I was installing the radio, I needed a ground. I ran it to the ground white coming out of the harness that went to the stock radio. I never could get it to work so I OHMd the ground to the battery and that same factory ground lug was not a good ground. I ended up running a new wire from the battery negative to that factory ground lug and the radio started working. I ended up just leaving that ground wire installed and ran another new wire to the radio by itself for a dedicated ground.
alright so the white wire to headlight switch (ground) is good. Now the ground block on kick panel what does it ohm to the engine block or the negative batt cable? It sounds like the dash may need ground repair.
note never use ohm meter on a circuit that has voltage, it will blow the fuse in meter, at best. Always check for DC voltage before switching to ohm.
You need min 3 grounds from battery. 1. heavy cable (2,4,6 ga) to engine. 2. 10 ga or so to radiator core support. 3. 10 ga to firewall or engine to firewall. I also suggest 1 from engine to frame, 8 or 10 ga.
note never use ohm meter on a circuit that has voltage, it will blow the fuse in meter, at best. Always check for DC voltage before switching to ohm.
You need min 3 grounds from battery. 1. heavy cable (2,4,6 ga) to engine. 2. 10 ga or so to radiator core support. 3. 10 ga to firewall or engine to firewall. I also suggest 1 from engine to frame, 8 or 10 ga.
Nutro
1/2 ton status
Wait so it IS good? I thought if it were good, it would show 000 on the meter? (I warned you I am not very good at electronics)
on the 2k scale .051 is ok. Anything under 100 ohm should work, which would be .100 on the 2k. Even so 100 has some resistance, either connector crimps, corrosion, a really long circuit.
you are showing 51 ohm a little high but workable. Does the white at switch ground to that ground post on the kick panel, or another spot in dash ?
you are showing 51 ohm a little high but workable. Does the white at switch ground to that ground post on the kick panel, or another spot in dash ?
Nutro
1/2 ton status
Ah ok I see. Now, that is the best question that I cannot answer and I would LOVE to find out. I don't know where that wire goes.
I don't think we can trust any of his ohm readings. Notice that in the first reading he got a Negative .051. He may have just put in a dash for semantics, but if he actually got a minus reading, then there was some voltage in the circuit.
In this case, his best bet in looking for grounds would be to grab one of those cheap clear icepick test lights. Hook the cable end to a known good hot source and probe the grounds. If its good enough to light the test light, then its not completely bad.
And he could poke a known good ground, and see how bright the light is. Anything dimmer than that is bad.
I know, knowing the amount of resistance is nice, but these grounds need to be tested under at least a partial load, certainly more than his meter, and the light will be easier for his skill set until we get him trained a little more in electronics.
In this case, his best bet in looking for grounds would be to grab one of those cheap clear icepick test lights. Hook the cable end to a known good hot source and probe the grounds. If its good enough to light the test light, then its not completely bad.
And he could poke a known good ground, and see how bright the light is. Anything dimmer than that is bad.
I know, knowing the amount of resistance is nice, but these grounds need to be tested under at least a partial load, certainly more than his meter, and the light will be easier for his skill set until we get him trained a little more in electronics.
sometimes if a circuit has a bad ground, it manages to find a ground through another circuit. I suspect this might your case. When this happens both circuits don't behave like normal. So the dome lights, under dash lights are 1 circuit, and the instrument lights are another. If one of these circuits lost it's own ground but found away share the others ground, there may not be enough current to complete the path, depending on where the 2 circuits are shorted together.
electricity is like water, it will find a path, and want to be equal.
electricity is like water, it will find a path, and want to be equal.
Nutro
1/2 ton status
Is there a circuit that shares a ground with the Cig lighter/Horn? If I push the lighter in to heat the element it pops the fuse. I ran a new ground when I installed it. I unplugged the hot lead and ground and removed the whole lighter assembly a few days ago but it had no effect on the headlight switch problem.
@Fordum I can certainly try that probing grounds. I do have a test light.
@Fordum I can certainly try that probing grounds. I do have a test light.
I thought the courtesy fuse dome lights and cigar lighter where on same fuse, I haven't looked it up. I suspect the lighter is itself having an issue.
i forget what year truck are we dealing with?
One thing to check about the lighter before you might wind up chasing down a dead end rabbit hole. The lighter element may be shorted.
I just went back and reread the thread because I thought someone else had mentioned that. Sure enough, you said the element was new, never used.
Hang out long enough on this forum, and you will hear horror stories about new parts that were bad out of the box. I would try the old element, or try the new one in another car to be sure.
When you are starting out troubleshooting a problem, you can check the most likely stuff, jump around a little bit and often hit on it if you are making thought out guesses.
But, when the easy stuff does not fix it, then you need to get very methodical. And that means check everything. Getting low voltage on a circuit? First check the battery. Sure its good, but check it anyway to eliminate it just in case.
Never assume NEW=GOOD.
Ask anybody here..........
I just went back and reread the thread because I thought someone else had mentioned that. Sure enough, you said the element was new, never used.
Hang out long enough on this forum, and you will hear horror stories about new parts that were bad out of the box. I would try the old element, or try the new one in another car to be sure.
When you are starting out troubleshooting a problem, you can check the most likely stuff, jump around a little bit and often hit on it if you are making thought out guesses.
But, when the easy stuff does not fix it, then you need to get very methodical. And that means check everything. Getting low voltage on a circuit? First check the battery. Sure its good, but check it anyway to eliminate it just in case.
Never assume NEW=GOOD.
Ask anybody here..........
Nutro
1/2 ton status
The headlight switch pops the #2 fuse and the lighter pops #1
It's an '88
It's an '88
maybe this help.
fuse block
Nutro
1/2 ton status
The headlight switch pops the #2 fuse and the lighter pops #1
Here are the readings I got. My memory was off a little.
Here are the readings I got. My memory was off a little.
rampage
3/4 ton status
It doesn’t really matter since the readings are pointless. If you’re just measuring resistance start at the lowest setting possible and then dial it up until you don’t get an ‘Err’ or whatever your meter designates as too much for it to read for that setting. So set it to the 200 ohm setting and measure the resistance (ie don’t call it ohmimg you newbie!
). You won’t hurt the meter by doing this. For a good ground to ground connection you should have at least under 1 ohm - close to zero resistance in other words.
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