Chevy Nova Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
Ok I have been trying to install my ammeter as some may know from my other posts. Today I was hooking up the lights from the gauges and was going to run it off the light switch. I have my tach hooked up so I know this works. So when I attempted to hook my gauges up now nothing works. No internal lights that run off the headlight switch work, none. I thought maybe it's the gauges so I disconnected them and nope that aint it. I checked the fuse and I found something. The fuse isn't burnt but there is no power going to it at all. I cked it with my tester and ck'd the others and thats the only one that has no power. I ck'd and changed fuses. Is there a relay? or something else? I'm just ticked off cause it was working before.:mad:
 

·
Premium Member
Joined
·
8,046 Posts
Most likely you blew the fusible link in your wiring harness. The ammeter can't be hooked to the light switch. Unless you use a shunt it has to put in line with the alternator to battery wire. All of the current stored in the battery and produced by the alternator is on that wire. Be sure to use good wire and make sure it doesn't ground out because it will start a fire. Do yourself a favor and buy a cheap replacement voltmeter. It can hook to almost ant 12 volt source and will work.

http://www.autometer.com/tech_faq_answer.aspx?sid=1&qid=5
How to wire an ammeter
http://www.autometer.com/download_instruction/642d.pdf

Which is better for monitoring a vehicle's electrical system - a Voltmeter or an Ammeter?

Short answer:


A voltmeter, by far.


Electrical guru Mark Hamilton of M.A.D. Enterprises points out that amperage is a measure of current flow, so an ammeter is actually a "flow meter" that's intended to measure current flow to the battery (under normal conditions) or discharge from the battery (in the case of alternator system failure). On a typical flow meter, all output must be directed through the device to obtain an accurate reading. In the ammeter's case, that means all the alternator output used to recharge the battery must first be routed through the ammeter under the dash. Which requires a heavy-gauge cable and presents a possible fire hazard. And the ammeter itself must be able to handle all this current flow, so it must have a higher current rating than the alternator's maximum rated output.


All this might be worth the hassle if the ammeter produced reliable information. But the ammeter can only measure the amount of current output to the battery for recharging purposes: When the alternator recharges a "low" battery, the ammeter indicates a high charge rate; with a fully charged battery the voltage regulator reduces alternator output, and the ammeter is supposed to indicate a very low charge rate. But how can you really tell the regulator has reduced alternator output because the battery is fully charged? Maybe a diode in the alternator rectifier failed, or the alternator belt slipped after it warmed up, just as if the battery were fully charged. Or maybe the meter indicates a medium charge rate most of the time-does the battery want this much or could the voltage regulator be overcharging the battery?


On the other hand, a voltmeter works like a fuel pressure gauge-but instead of measuring fluid in psi, the voltmeter measures electrical system pressure in volts. Just like a fuel pressure gauge, a voltmeter only needs to tap into a circuit; all the fuel (or electricity) does not have to detour through the gauge itself. Voltmeter installation is easy, quick, and safe: It hooks up to a fused, ignition-switched "off/on" source and does not require any modification of the circuit used to recharge the battery or any part of the alternator/regulator system. In short, the voltmeter installed at the dash will be a stand-alone circuit.


The voltmeter directly measures the result of charging-system performance. With normal alternator/voltage-regulator function, battery voltage is maintained at 14.0 to 14.5 volts-and this is reported directly by the voltmeter. In the event of alternator-system failure, voltage will be low and continue to drop as the battery discharges. In the event of an "overcharge" condition, the voltmeter will climb above its normal zone. In summary, there is no chance for misinterpreting a voltmeter's readings as can happen with an ammeter.


Voltmeter vs. Ammeter?


Auto Meter offers both, but for most applications a voltmeter yields a safer installation while providing more useful information on charging-system conditions.
 

·
Registered
Joined
·
70 Posts
Discussion Starter #3
ammeter

I'm not even worried anymore about the ammeter gauge. My concern is the instrument panel lighting that doesn't work. It worked before now it doesn't. And no I never got the ammeter gauge working. I ck'ed the fuses they are all good. When I hit the switch for the lights all my external lights work. Just the interior lights and dash lights wont go on. Help :(
 

·
Registered
Joined
·
70 Posts
Discussion Starter #4 (Edited)
?

I found the strap that goes to a screw underneath the dash by the steering column disconnected. What do I connect it to? Filaments on bulbs are good. I tested the circuit on the fuse block and it has no power at all..so power where ever it comes from is not getting to the fuse block just on that circuit the one that says [INST. LPS] all the others have power. Just that one doesn't . The worst part is like I said it worked before.



I tried new fuse and cleaning the receptacles since they are a lil corroded.
 

·
Registered
Joined
·
566 Posts
If memory serves, the lights switch feeds power to the dash circuit.

you COULD have a co-incidental problem with the light switch.

Go to the schematics post of this forum section and research it.
 

·
Registered
Joined
·
70 Posts
Discussion Starter #7
schematics

Yes it does light switch does feed power to the panel. But which ever wire feeds power to that fuse link is not doing it anymore. I'm going to do what you said and look at the schematics on the forums and see where that wire leads to. I was using the chilton's manual but not very detailed.

How do you posts video on here?
 

·
Registered
Joined
·
70 Posts
Discussion Starter #8 (Edited)
grounding strap

Might want to look closely at your ground strap system behind that instument panel. When you bolt the plastic instrument panel to the dashboard there is a ground strap that makes contact.

There should also be a ground strap going from the wiper/headlight switch area to the metal speedo housing where all your bulbs are.

Check to make sure this strap is there and also check the screw that holds the ground strap. If this screw gets loose or is missing, no ground and no lights.
This is grounded to the screw but what does it connect to? Can someone post a pic of theirs?



I think like 350 4 speed said this might be my problem. It's grounded to a screw under the dash, but what does it ground? It must have slipped off the other end.
 

·
Registered
Joined
·
70 Posts
Discussion Starter #10
the investigation continues

I unbolted the fuse block from the firewall. I turned it around and jumped the always hotwire to the inst fuse ,,, and then guess what my lights came on. But they stayed on even with the switch off. Then I said ok my fuse block is good let me ck the light switch..bam the switch was so hot I couldn't even touch it, especially around the ceramic or white part whatever it is. I ck'd and there's power going into the switch .. The only power going out is to the headlights all the others nothing. Does this mean my switch is bad?????

Somebody anybody:eek:
 

·
Registered
Joined
·
1,211 Posts
I am experiencing the identical problem you are discribing, both with the ammeter and panel lights after replacing the instrument cluster. I too am about to give up on the ammeter. So have you decided the panel light issue was the light switch?
 

·
Registered
Joined
·
70 Posts
Discussion Starter #12
Light switch

I took the light switch to a guy at work he works on forklifts. He tested it for continuity and put power on it with a handy dandy Snap on meter. He said it was the switch. He said there is more than one circuit in there. I haven't bought the new switch yet. But trying to install ammeter was a bad deal at least on my part. I found out recently that I burned out that bulb in my tach also.
 

·
Registered
Joined
·
1,211 Posts
I took my light switch out last night and checked it. Same issue, no power output for the lamps. I jumpered it at the fuse box and got lights. Chevy2 Only sells a new light switch for $17. It may also still be available at the NAPA dealer, in that I suspect this same switch was used on several models and years.
 
1 - 16 of 16 Posts
Top