Well I took the Chevelle out this morning and I forgot to wear a sweater or jacket. So I just cranked up the heater to max after the motor warmed up and I was driving. Anyway I was cruising along just fine and then I put in the clutch to prepare for a stop and the motor just shuts off. I turn off my heater and start it back up. It starts just fine but idles really low. About 350 to 400 rpm instead of the normal 700rpm. My first impression was that since I had my subs and stereo going that I was taking too much power from the battery and the alternator couldnt keep up at idle with the heater on full. But I dont know if the heater drains alot of electrical current. I didnt turn the heater back on for the remainder of the trip and at the next stop I put in the clutch and the idle was fine and normal. Was I just putting too much strain on the battery and alternator?

Could be. How much does your amps draw and how big is your alternator? I once had a customer that was eating batteries every couple of months though all systems tested good. Turns out his killer stereo was drawing more power than the alternator put out, discharging the battery to a point that his ignition system wasn't getting enough power. The battery would recharge when he wasn't cranking the stereo up but the constant deep discharge/recharge cycle was killing the batteries. A larger alternator solved the problem.

Hmmmm I will have to check. I forget what the alternator puts out. I only have this problem when I turn the heater on. Otherwise I have had the same setup for a year without changing the battery.

the only thing in the heater that takes any power at all is the blower motor- and that's only something like 30 amps when it's on "hi".
does it do it when the heater is on but everything else is off? do your lights dim when you turn the heater on?

if it only did it this one time, and if you hadn't driven it very far, it could be that the choke disengaged before the engine was up to running temp.

I had the same problem on my 70 Monte Carlo, just like you said its the radio drawing to much not the heater. I got an electrical kit from some company (can't remember who) and converted to a 1979 Camaro alternator. Problem solved.

the only thing in the heater that takes any power at all is the blower motor- and that's only something like 30 amps when it's on "hi".
does it do it when the heater is on but everything else is off? do your lights dim when you turn the heater on?

if it only did it this one time, and if you hadn't driven it very far, it could be that the choke disengaged before the engine was up to running temp.

I will check on the lights. But when I turn the heater on full with the radio off it always took away about 150rpms or so.

There is no choke on my 4150 :thumbsup: But it did give me some trouble today. You have to keep in mind that the primary metering block has lots of corrosion. Anyway, It was warming up at a steep angle and was slowly wanting to die. So I just thought it was flooding itself and that it will balance out after a while. Well I was wrong. I ended up stopping about a mile down because it kept dieing and barely idling. I checked my float level and it was actually very lean. It was way below the proper level. So I just take out the needle assembly and actually found a piece of metal thread about as thick as a hair and maybe a half a cm long on the needle. I brush it off and put everything back together. Set my float right and take her on home. The only problem I have left is that it now idles over 1000rpm which is something I will have to look at probably tomorrow. I never touched the idle screw.

I had the same problem on my 70 Monte Carlo, just like you said its the radio drawing to much not the heater. I got an electrical kit from some company (can't remember who) and converted to a 1979 Camaro alternator. Problem solved.

A guy told me that I should get some device for about a hundred bucks that prevents the subs from drawing too much at one time. The power lie goes through it and then into the subs. I cant remember what its called though.

Maybe a capacitor. A big one

Maybe a capacitor. A big one

Yeah thats what it was! He told me it would help out.

Does your car have A/C? If it does, the compressor kicking on will drop the idle speed.
BillL

Does your car have A/C? If it does, the compressor kicking on will drop the idle speed.
BillL


Nope no A/C :D