Amp stalls P/U truck

[njoutlaw]

I have a 2 pill no name any where amp. Aluminum ( I think) box with fan on top, AM & SSB toggle with I'm guessing mod knob.
hot wire ran to battery with big stereo amp fuse block with 2 30 amp fuses one fuse to amp and other fuse to CB (DX 959), ground wire ran to driver seat bolt.
wHILE VEHICLE IS RUNNING @ IDLE and I key up my truck will stumble and stall. Any suggestions?

[jessejamesdallas]

Bigger alternator...(higher amperage alternator)

Also, I would run that ground wire to the frame...seat bolt is probably just connected to the body of the truck, and not the frame, which is not going to give you the best grounding point.

[HOUND DOG]

I had this problem with my jeep wrangler and a 3 pill. The alternator was not big enough to power the amp along with headlights. I had to rev the engine up to use the amp:-) I finally just took the amp and radio out. Do you have a full size pickup or a mini?

[njoutlaw]

Thanks JJD. I've been thinking of upgrading Alt..
92 Chevy Silverado 1500.

[jessejamesdallas]

Thanks JJD. I've been thinking of upgrading Alt..
92 Chevy Silverado 1500.

probably has a stock 105 amp alternator...You can get a 200 amp direct replacement Delco... 145 amp would be a improvement... Need to shop on line tho, most auto part stores will only have the factory replacement alternators.

There's several listed on the auction site starting at $119 for a 200 amp that will fit your truck.

[dgbacb4148]

You did not mention the gauge of wire or length you are using. As JJD suggested, a larger Alternator is necessary, and the ground wire should be to the engine block. Make sure your terminal ends are soldered and keep the length to a minimum. This has always been a trial/error configuration because every vehicle is different, JMHO and good luck to you.
David g...............

[MDYoungblood]

A bigger alternator might help, when running an amplifier everything must be in good working order, alternator has decent output, battery up to par, etc. The negative wire to the seat bolt should be fine, it is solid to the cab body and the batteries negative is connected to the body, somewhere there should be a lead to the frame but that is not always the case. I wouldn't think the draw of a 2 pill would be enough to drag down the engine from idle, might need a tuneup and the idle adjusted.

3's

Greg

[drdx]

Rf (as in your signal) could be getting into the vehicle computer via a wire that is just long enough to make an accidental antenna. Attach a 9 foot long piece of insulated wire to the amp case and see if it fixes the issue. The other end of the wire is not connected to anything but tape the end to it isn't touching any metal. Picture it as an antenna for the ground side. The wire would create a counterpoise/tuned ground. If the battery connections and alternator are good there is no way an amp of that size would have enough drain to kill it via amp draw alone.

If that doesn't work then you start looking elsewhere and maybe grounds trapping things like exhaust and bed.

-drdx

[Scipio Kid]

Completely agree with drdx, even with a heavy load, you'd have to overwhelm the alternator and then drain the battery too. Keying up once couldn't do that but interference with the computer could. The computer runs the engine (and tranny in most cases) screw it up and nothing works. It might not be affecting the computer directly but it could be interfering with a crucial sensor, sending the wrong info to the computer. I'd follow the advice above (and also have a nice steak). Then I'd fire that thing up again and see what happens. If your amp is toast, it ought to be blowing fuses, not stalling the engine. If your 30 amp fuse is intact, you're not inducing enough load to hurt anything, much less stall the engine.

[njoutlaw]

Thanks for the replies and tips. Truck was tuned up maybe 2 months ago.
at the moment I am shopping for a larger alt.
I am going to re ground the ground wire to frame or other suitable location other than seat bolt and possibly try the 9ft wire to amp case trick and hope for the best.
Amp clicks when I key up so its doing what it should but maybe like mentioned the ground isn't accurate enough.....
I will keep updates as I can, maybe someone else will be in the same/similar situation and my trial and error may help.
until then I'll be readn the mail.

[Deleted User 14541]

A 2 pill doesn't need much more current that the blower motor for your AC or your headlights. If your alternator had no issue keeping up with the headlights and AC running at the same time turn them both off and it will have no trouble with a 2 pill.

DRDX knows what's going on. Ideally an antenna would roof mounted on a large vehicle roof. Think of a suburban as best case scenario. That huge roof provides a massive counterpoise and there are rarely issues with RFI at most power levels. With a smaller roof or an antenna mounted in a compromised position the outer part of the coax shield is more likely to radiate. This is called common mode current and it basically brings RF into the vehicle where it can wreak havoc on anything electronic.

The 9 foot wire on the amp case can treat the symptom but the cure would be to use a better antenna mount or a common mode choke to force the return current to flow on the vehicle body instead of the coax shield. Putting the wire on the amp case is like taking a radial off a base antenna and bringing it inside. Even though it might make the system usable the efficiency will not be as good as it could be. If you put a radial anywhere attach it to the ground side of the antenna mount..think ground plane base antenna or dipole.

For a choke you can use the right mix of ferrite cores around the coax at the antenna feed point or wrap a choke. About 5 turns of coax around a 5 inch form should make a difference. Google "ugly balun" to see the choke. I prefer the ferrite but a choke works if done right and you have room for it.

The funny thing is that moving the negative cabke of the amplifier or changing the length of it can have the same effect at the 9 ft wire on the amp case. You may treat the symptom and think you solved the problem.

[Scipio Kid]

OK, I really didn't understand much of that but it sounded so cool I just have to agree. And now I want to do it to my truck even though I don't have an amp and my radio's working great.

[Monk]

You could try turning on your AC when running the amp.
The AC in vehicles usually has a servo that increases the idle
speed to keep the motor from stalling. Some of the older
servos you could adjust the idle too.

Monkradio

[443 Arizona]

big wire straight to the battery.

[KN6SD]

I have a 2 pill no name any where amp. Aluminum ( I think) box with fan on top, AM & SSB toggle with I'm guessing mod knob.
hot wire ran to battery with big stereo amp fuse block with 2 30 amp fuses one fuse to amp and other fuse to CB (DX 959), ground wire ran to driver seat bolt.
wHILE VEHICLE IS RUNNING @ IDLE and I key up my truck will stumble and stall. Any suggestions?

The other replies covered a lot... However, I don't think anyone mentioned Coax Quality and if it is run next to the Vehicle CPU.. Also, Antenna SWR & Coax runs can have a huge effect on vehicle RFI. I also agree with the other posters about your power output, 150 to 200 watts shouldn't kill a vehicle with a properly installed radio/amp and quality coax with a tuned antenna...

I hope you figure it out... Best of luck..

73,
Russ

[nk14zp]

Sounds like it's RFI. Is the ant properly grounded? Coax good? Swr good? Hows the bonding?

[jessejamesdallas]

Old post..But for those saying "RF" maybe getting into the computer of the truck... He said it was a 1992 Silverado...."no computer"

I agree a 2-pill shouldn't kill the truck...But if the battery's weak, alternator on it's last-leg, who knows...would like to know what he found out tho.

[nk14zp]

ttps://www.autozone.com/engine-manag ... l-computer

[Skyraker426]

I had the same issue with my... wife's? Honda, Ok, it's mine... Running a 4 pill on a stock alternator. I upgraded the antenna system and installed a ground wire on the amp to the body. The hood, trunk and doors are bond-strapped as well as the exhaust and rear axle. Car runs great now and my voltage only drops to 13.3 at highway speeds and 12.3 at idle. I'm gonna mount another battery in the trunk to help with the voltage drop.

Good luck! RF is sneaky!

[MDYoungblood]

Old post..But for those saying "RF" maybe getting into the computer of the truck... He said it was a 1992 Silverado...."no computer"

I agree a 2-pill shouldn't kill the truck...But if the battery's weak, alternator on it's last-leg, who knows...would like to know what he found out tho.

It's not really a computer but the HEI ignition has an electronic module that can be effected by RF, especially the cheap ones. Wonder if he ever figured it out.

3's

Greg

[jessejamesdallas]

Old post..But for those saying "RF" maybe getting into the computer of the truck... He said it was a 1992 Silverado...."no computer"

I agree a 2-pill shouldn't kill the truck...But if the battery's weak, alternator on it's last-leg, who knows...would like to know what he found out tho.

It's not really a computer but the HEI ignition has an electronic module that can be effected by RF, especially the cheap ones. Wonder if he ever figured it out.

3's

Greg

Good question...Think we need a new rule that once you figure out what solved the problem to your question, you have to post the answer or be banned for life from asking anymore questions...

[redlght]

Where is the amp tapped into for power?
I once worked on a car that had rough running issues when i would test drive it nothing would happen. When the car came back the radio was on and the car was running badly i turned off the radio and it ran fine. The louder you turned up the volume it would draw more power and the worse the car ran. It was an after market radio and and tapped into the fuel injection power wire.

[295 antenna]

Where is the amp tapped into for power?
I once worked on a car that had rough running issues when i would test drive it nothing would happen. When the car came back the radio was on and the car was running badly i turned off the radio and it ran fine. The louder you turned up the volume it would draw more power and the worse the car ran. It was an after market radio and and tapped into the fuel injection power wire.

I believe in the first post he says (straight to the battery?) or did i read that wrong ?