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Jean-Marc Dugas
05-24-2010, 11:05 PM
I was finally able to take the 67 for a drive on the highway tonight, and on a lonely stretch of road got the B&M a good try.

It is indeed very loud, but it also draws a whole lot of current. The headlights dimmed right down and the ammeter went down (or up) from 1/2 to 1/4 instantly.

I am afraid that if i use the B&M for to long, I'm gonna blow something, or burn the car.

When i installed the siren last winter, i followed the diagrams from the B&M website. Could I have a bad alternator, bad batteries, etc...

Any suggestions on what i should do to fix this problem?

John ED Renstrom
05-25-2010, 01:15 PM
current draw is less then the Q buy a lot. so lets think about how you did this. one possibility is a poor ground. you can try to run a ground strap from the siren to the frame. were your mounted you could have enough corroding to give it a weak ground. the other is to small a wire on the hot side. at least a #4 of bigger would be what you need and a direct connection to the battery. then of course what are you using for a battery size wise and how big is your alternator. most of the car with these large current draw had the dual batteries for the reserve amps. at lest a 100 amp alternator is necessary to keep up with the everything. then of course there are the connections to the lights are they poor. but to me it sounds like everything is working just fine
you cycle that much current and the amp gage will go crazy. when you do it just go white knuckled and think "code run, code run" and forget to look at the gage. how to tell is, turn everything on and let the siren run. for say at least 2 minutes. then shut it all down. is the amp gage now showing a high rate of charge for longer then you ran the lights or does it drop right back to normal soon after things are shut off. it it does that your not taxing the system. then to, if it stays on the Neg side with everything running, don't cycle the siren but let it run. then does it stay on the neg side or come back to 0. if it stays in the neg your charging system is to small for you current load. shut off the siren and the lights one at a time till you can keep up. that will be the load the system can handle for now. but just cycling the siren will really make the gage swing wild that's normal. as is a wink in the headlights. if they dim out thats not.

Richard Vyse
05-25-2010, 02:36 PM
Speaking of which, how much current will it take to run a Federal "Q2B", a Double-tone, and an Federal Inceptor? I think I will leave the double-tone hooked up even after installing the "Q2B".

Todd Merrifield
05-25-2010, 02:47 PM
Speaking of which, how much current will it take to run a Federal "Q2B", a Double-tone, and an Federal Inceptor? I think I will leave the double-tone hooked up even after installing the "Q2B".

Do you make a lot of runs past the hospital for the deaf? Or are you trying to get their admittance numbers up?

John Dorgan - Deceased - 1938 - 2012
05-25-2010, 04:47 PM
Federal's installation instructions for the Q call for a 400 amp breaker or fuse in the system. Does that tell you anything? I would consider a 125 amp alternator a minimum for a vehicle running a Q.
John Dorgan

Steve Loftin
05-25-2010, 04:57 PM
What size (amperage) is your alternator? What size (CCA) are your batteries?

Todd Merrifield
05-25-2010, 06:20 PM
Hey Jean-Marc,

I just went out and checked mine, because I couldn't remember. I have an inductive ammeter that I can put right around the positive wire going out to the sirens.

When I first hit the button on mine the meter reads 240 amps. As you let them run it drops down to 120 amps. That is for TWO sirens, so if you divide that in half each siren of mine is pulling 120 amps on startup and 60 amps for continuous use once they are up to speed.

The one I sent you that you are using now turns MUCH more freely than the ones I am using, so a safe bet is that yours is pulling 100 amps on startup and 50 amps for continuous use. If you have it properly wired with the correct gauge wire, and you haven't upgraded your alternator or battery it is understandable that it would dim your lights, since you are using almost all of the capacity of your charging system to drive your siren (on startup).

That siren motor is basically a glorified starter motor. If you try to start your car with the headlights on you should see similar results.

I am running a dual battery system with an Optima starting battery (which the sirens are wired to), along with an aftermarket 200 amp alternator to allow me to run all the lights and sirens at the same time. The lights are all wired to a deep-cycle battery that is isolated from my starter battery so I can park and run the lights for a while and still start the vehicle later. I wired the sirens to the starter battery because I don't ever run them much more than a few seconds when the vehicle is parked and not running. I also have the sirens hooked up with 8 gauge wire, which is really too small for extended use, but like I said I only ever run them long enough to spool up then shut them off. If I were to use it in service and run the sirens for extended periods of time I would want to put AT LEAST 4 gauge wire in there (for 2 sirens), as the wire I have now would probably heat up pretty good over extended use. Wire size gets bigger as the number gets smaller With the biggest automotive wire commonly available being "0" gauge. 0 gauge wire is roughly twice the diameter of welding cable. You can get bigger, 00 gauge, but it is rarely needed in an automotive application. 4 gauge is about a half inch in diameter, 8 gauge is about 1/4 inch, household lamp cords are usually about 18 gauge per conductor.

Hope this helps.

Brendan Martin
05-25-2010, 09:29 PM
Speaking of which, how much current will it take to run a Federal "Q2B", a Double-tone, and an Federal Inceptor? I think I will leave the double-tone hooked up even after installing the "Q2B".

Wow, that will clear some traffic!

Russell Dalziel
05-25-2010, 10:21 PM
Wow, that will clear some traffic!

NO more of a traffic Jam as the Pumpkin Orange car Blocks the roadway. LOL


Russ

Kevin O'Connell
05-26-2010, 05:19 AM
Some very good points have been raised in this thread. I'd like to add my inflated two cents.

B&M tests every siren before it leaves the shop for function and current draw. Our test bench has a very accurate ammeter. Your siren is guaranteed to draw less than 70 amps. Actually, it draws 60 amps at full wail with an inrush current (or startup current) of 150 to 170 amps. 6 gauge cable is recommended for runs under 15 feet, 4 gauge for 15 to 25 feet. Trust me on this, I know the guy who owns the company. Never use a cable smaller than 6 gauge as undervoltage burns on the commutator will eventually develop, severely shortening the life of your armature.

Compare these figures to a Q, which draws 120-125 amps maintenance current, 350-375 inrush current. Federal absurdly recommends 4 gauge cable which is only rated at 95 amps continuous use. Fortunately, ambulance and fire apparatus builders know better and universally use 2 gauge, rated at 120 amps.

If your lights dim severely it's a safe bet that your body feed is deficient. Start at the source: Batteries. Not battery, batteries. When you add a real siren, you join the Varsity and you'd better have the juice to run with the big boys. Your batteries should be matched and replaced as a set. Dissimilar batteries will charge at different rates. Battery terminations should be cleaned and inspected regularly. Remember, battery posts are not the only battery terminations- there's another end on each cable which also needs to be cleaned and inspected. Cables themselves should be adequately sized and in good condition. Cables with clamp-type replacement ends are not in good condition. Also, remember that corrosion can form on the cable inside the lug end as well as the battery end. For this reason I make all of my own battery cables using very high quality components. I have to disagree somewhat with Todd as I never use cranking circuit cables under 2/0. In fact, the usual cranking circuit cables I make are 4/0. Vehicles with 300 amp alternators get 350MCM cable. You don't find that at Auto Zone.

Feeds for any non-Pontiac accessories should come directly from the batteries, not from the Pontiac body feed on the starter solenoid. That body feed terminal should also be inspected , as it is often the source of troubling voltage drop.

In order to sustain the load of warning lights and siren a serious alternator would really help. The battery lead from the alternator should be sized to match or exceed the output of the alternator. If your car has the stock Pontiac alternator and wiring harness (judging by your description of your amp gauge, it sounds like it does) your batteries will discharge markedly in the shortest of parades. A high quality volt gauge is a better indicator of electrical system condition than an ammeter, by the way.

Jean-Marc Dugas
05-26-2010, 06:10 AM
Thank you all for your comments. I will have a look at the set-up within the next few days and will report back to let you know what's up.

Todd Merrifield
05-26-2010, 07:36 AM
I never use cranking circuit cables under 2/0. In fact, the usual cranking circuit cables I make are 4/0. Vehicles with 300 amp alternators get 350MCM cable. You don't find that at Auto Zone..

Just for clarification for those who don't know, after you get to "0" in wire gauge size the next biggest size is 2/0, then 4/0, etc. 2/0 is what I was referring to as "00".

Also, for anyone who may not know, Kevin is the owner of B&M Siren, the manufacturer of the sirens in question, so any information he gives about correct wire size should replace any information given by me. I'm just a goofball with a couple sirens annoying his neighbors. :burp:

Richard Vyse
05-26-2010, 11:49 AM
Federal's installation instructions for the Q call for a 400 amp breaker or fuse in the system. Does that tell you anything? I would consider a 125 amp alternator a minimum for a vehicle running a Q.
John Dorgan

My Criterion has a huge alternator on it, is it large enough for a "Q"? I don't know the size off hand.

Paul Steinberg
05-26-2010, 12:50 PM
My Criterion has a huge alternator on it, is it large enough for a "Q"? I don't know the size off hand.

If it is larger diameter than the Q and it weighs more than the Q, the answer is a qualified yes, with reservations. Size matters in some things, and alternators isn't one of them. This is the "qualification" in my response. There is more than size and output, as Kevin explained. Too many variables to make a determination based on the single word "huge"...

Steve Loftin
05-26-2010, 05:37 PM
My Criterion has a huge alternator on it, is it large enough for a "Q"? I don't know the size off hand.

1970s procar ambulance alternators:

Cadillac - 100-amp Delco , std. on all commercial chassis
Cadillac - 145-amp Leece-Neville, optional; usually seen on ambulances, have seen them on a few combinations

Olds - 61-amp(?) Delco std.; 120-amp optional*

Pontiac - 61-amp(?) Delco std.; 105-amp optional*

*Higher available on special order; expensive, usually requiring special (hand-built) bracketry...space was also an issue.

Richard Vyse
05-26-2010, 11:16 PM
1970s procar ambulance alternators:Cadillac - 100-amp Delco , std. on all commercial chassis
Cadillac - 145-amp Leece-Neville, optional; usually seen on ambulances, have seen them on a few combinations
.

So the alternator on my Criterion should be able to handle a "Q" then. Right?

Jean-Marc Dugas
06-01-2010, 11:37 PM
After looking at my set-up again, I think that I have the 130 Amp alternator.

I used #8 wire, so I guess that I will upgrade to #6 gauge. I will also install a direct body feed.

The batteries probably also need to be replaced along with the battery cables.

Once I have all of this done, I'll give you guys an update.

Thanks again for the help.:thumb:

Paul Steinberg
06-01-2010, 11:49 PM
6 gauge cable is recommended for runs under 15 feet, 4 gauge for 15 to 25 feet

I would do some measurements before you purchase the wire, since 15 feet isn't a very long distance once you start pulling the wire. I just got off the phone with Kevin this evening, and he recommended my using 4 gauge wire to my Super Chief. The difference in cost isn't much when you consider the longevity factor. I suggest that you use a tailors cloth tape measure to see how far you will be running wire... or use a piece of string and then measure the total distance, taking into consideration that string is a lot easier to move around corners than a wire...

Jean-Marc Dugas
06-02-2010, 02:25 PM
Good point. Thanks Paul.

Jean-Marc Dugas
06-03-2010, 06:54 PM
Here is a picture of my alternator. I think that it is a 130 Amp.

http://www.professionalcarsociety.org/forums/picture.php?albumid=5&pictureid=635

Kent Rogne
06-08-2010, 06:00 PM
i have four 184 beacon rays, four tunnel lights and a Q siren to add. Plus stock 125 gm alternator. is that big enough of an alternator? My cables for the Q are same size as battery cables, are they too small? and should the cable from the battery to the amp relay to the Q have bigger cbles running to it as well? I'm thinking seriously of dumping the Q for a Band M so I dont burn something up. I dont have to Q hooked up yet. but when I run all the beacons and lights the 125 alt gets real warm and the belt seems to squeel when I flip on the back two beacon rays when i put the ambulance in drive and take off

Kent Rogne
06-08-2010, 08:16 PM
Yep! that looks like mine. Mine is a 145 amp, not a 125 AMP. My mistake. Guess I should go #4 cable all the way around, even from alternator to system? I don't think its the correct size. Didn't know until today that it does make a difference

Kent Rogne
06-09-2010, 04:58 PM
Heres a question...How big does the cable comming from the alternator to the batteries have to be a #2 or #4 ? does this have to be done at a auto electric shop? or can you buy the cable someplace?

Todd Merrifield
06-09-2010, 07:00 PM
Heres a question...How big does the cable comming from the alternator to the batteries have to be a #2 or #4 ? does this have to be done at a auto electric shop? or can you buy the cable someplace?

The cable going from my alternator to the battery isolator is a relatively small 6 gauge. It was supplied by the company that made the alternator and included as part of the kit.

John ED Renstrom
06-09-2010, 10:35 PM
that's about the only size i have seen on alternator. remember it's a charge wire not a draw wire. the heavy amps need on start up are what require the big wire. the alternator goes to the regulator and nothing coming out of it is any bigger either.