12.4 volts???

[jvazquez53]

Trickle charge your battery for a few days to make sure it's getting a full charge. If you drive a lot of short trips you may not be doing your battery justice. My Optima would do the same to my alt output when not fully charged. I would run 12.2-12.8 once I charged up the Optima I run at 13.8-14.2

This may apply. I have the truck on trickle charge, and when I use it, is on very short trips. Maybe I need to use it more often.

 

[jvazquez53]

Do you have a factory RS3000 alarm system?

I had similar symptoms.
I replaced the battery, as my Ultragauge would register dropping voltage as I sat at a stop light, and battery tested as bad.
Problems persisted.
Replaced the alternator, as I assumed that the alternator was not keeping up and I had no idea if the alternator was original or not with 250K on the truck. (turns out it had a reman on it). New one did better, but not enough. Over time, it improved (why, I don't know....) but it is an O'Reilly special.
Replaced the battery again. Helped even more.
Had a no-start on the truck due to what appeared to be dead battery. Tried to jump and starter dead.
Replaced the starter.
Problems solved.

I believe I was having a constant drain from bad starter contacts, but I never measured it. Some of this stuff I replaced because I figured it was time so it was kind of PM as well as throw money at it to fix. I don;t normally do things that way, but I needed to refresh the parts anyway.

I also discovered later that the alarm system was causing random drains on the battery. It would go dead overnight sometimes, other times not. After the alarm decided to wig out, I ripped it out and have not had ANY electrical issues since.

I dont have a RS3000 but I have a Viper alarm. However my other truck which is similar, has a cheap alarm system but works fine. Charging system shows 13 volts plus all the time.

 

[BILT4ME]

I dont have a RS3000 but I have a Viper alarm. However my other truck which is similar, has a cheap alarm system but works fine. Charging system shows 13 volts plus all the time.

I would watch my voltage drop while sitting at a stop light from 14.2V drop continuously within 2 minutes to be 11.6V by the time the light turned green. This is with my headlights on, defroster fan, and radio. At 2500+ RPM I was at 13.5V to 14.2V.

And I did install new fusible links as PM.

 

[jvazquez53]

I would watch my voltage drop while sitting at a stop light from 14.2V drop continuously within 2 minutes to be 11.6V by the time the light turned green. This is with my headlights on, defroster fan, and radio. At 2500+ RPM I was at 13.5V to 14.2V.

And I did install new fusible links as PM.

Blue Sea 7187 285-Series Circuit Breaker Surface Mount 100A 632085171872 | eBay

That could be. One friend got rid of the OEM fusible link and installed one of these and said it works a lot better.

 

[george_tlc]

Do NOT meddle with circuit breakers in place of fusible links unless you really understand what each fusible link is protecting and the correct sizing to protect the downstream wiring that is on THAT SPECIFIC fusible link.

You'll get away with it most of the time, but if you ever have a wiring short you are gambling on the breaker opening before the wiring melts. A replacement harness and all the work entailed is hardly worth it.

The OEM fusible links were sized appropriately and chosen by engineers that understood the harness gauges that are downstream of the links. Don't second guess their design. If the links are healthy then they function perfectly fine - consider that toyota shipped more than a few dozen vehicles and they appeared to work just fine out the door...

Again I'll say that one needs to be methodical in working through electrical issues versus just listening to a whole bunch of recommendations to change things for the heck of it because it worked for someone. If you have a poor electrical connection and replace say the fusible links for a circuit breaker and that 'solved' the problem, the same could be said for having just put new (or the same) fusible links in and retightened/cleaned the connections in the process... Myths grow from such 'repairs'.

cheers,
george.

 

[jvazquez53]

Do NOT meddle with circuit breakers in place of fusible links unless you really understand what each fusible link is protecting and the correct sizing to protect the downstream wiring that is on THAT SPECIFIC fusible link.

You'll get away with it most of the time, but if you ever have a wiring short you are gambling on the breaker opening before the wiring melts. A replacement harness and all the work entailed is hardly worth it.

The OEM fusible links were sized appropriately and chosen by engineers that understood the harness gauges that are downstream of the links. Don't second guess their design. If the links are healthy then they function perfectly fine - consider that toyota shipped more than a few dozen vehicles and they appeared to work just fine out the door...

Again I'll say that one needs to be methodical in working through electrical issues versus just listening to a whole bunch of recommendations to change things for the heck of it because it worked for someone. If you have a poor electrical connection and replace say the fusible links for a circuit breaker and that 'solved' the problem, the same could be said for having just put new (or the same) fusible links in and retightened/cleaned the connections in the process... Myths grow from such 'repairs'.

cheers,
george.

Im holding up on that, the person that did this on his Cruiser he is an avionics electrician, very knowledgeable in the electrics field. If I were to do it, I would let him deal with it, he did it on his truck and is working great. In te meanwhile and since the fusible link is cheap, I'll probably replace it. the one on the truck looks pretty old.

 

[george_tlc]

Avionics or whatever... I bet he doesn't replace units in a plane with circuit breakers because he thinks they're good - if he does I'd rather not fly on a plane that he worked on Also, not sure why you would put a breaker in place of a fusible link unless you expect to be 'blowing' links all the time... and then you have another problem.

I would rather use a MIDI fuse in place of a fusible link (if I was going to meddle at all) since they are designed to behave similar to a fusible link in terms of overload capability and fusing characteristic. In fact on my old patrol I did replace the original fusible links with MIDI fuses, but then I also converted it from 24V to 12V (which of course changes the current that is flowing through the various circuits).

I'm a grey haired EE - so that's my 'title' for whatever it's worth

cheers,
george.

 

[jvazquez53]

Case closed! Went and tested the system with a really good multi meter and the voltage is a steady 14.4! I did put on a load, AC on, lights on, and stayed a steady 14.4. I believe that the dash gauge, which I know is not a good reliable reading, got me worried. What Im going to do is buy a good quality volt meter gauge and wire it directly.

 

[george_tlc]

Good! Hence my multiple times of specifying a 'decent' meter right at the battery terminals

cheers,
george.

 

[jvazquez53]

Good! Hence my multiple times of specifying a 'decent' meter right at the battery terminals

cheers,
george.

Thank you! Thats exactly where I started, at the battery, for good measure, I tested the alternator and checked out OK.
BTW George, your page is very interesting!