Stop Solenoid & Alt questions

[poopdeckpappy]

I had the stop solenoid replaced awhile back and here's the problem, it works fine when in the slip and SP is hooked up, however, underway it don't work worth a crap, now this really isn't big deal to kill it manually but I want to get it right.

I explained the problem to the shop and was told " there must be a voltage drop " so I checked the wiring and what I noticed was the wire from the button to the solenoid was #10 copper ( so that gets replaced ) and from the soleniod the alternator was a new ( by mechanic ) #12 or possibly #14 tinned ( my wiring diagram shows #10 ) so could this be the source of the drop ??


Also, I have a older 10si DelcoRemy Alt ( 63 amp ) and I'm looking to get closer to the 100 amp mark, now this alt was used on 69-late 70's model yr GM products, early 80's GM's went to a 12si alt ( same housing ) which ran anywhere from just under 100 amp up to 108 amp and use the same 1/2 belt.

So now I'm thinking, why spend several hundreds of dollars on a 100 amp Balmar alt when I could spend just over a 100.00 on a Delco/Duralast, especially since the one I have now has been in there from the beginning ( not counting rebuilds if any ) and at that price I could have new spare or two

What do ya think good ??, bad??

[sawingknots]

a stop solenoid works by allowing fuel through to the engine when the ignition is on so your problem isn't, not enough voltage but rather a problem in the solenoid itself.i don't know enough about alt.s to advise you about yours

[erps]

a stop solenoid works by allowing fuel through to the engine when the ignition is on so your problem isn't, not enough voltage but rather a problem in the solenoid itself

I think there also might be a few that are designed to be open (fuel on) in the run position and use a momentary solenoid to close them to shut them off.


Jim,

Those smaller wires you found most certainly could be a source for resistance, especially in a warm engine room. Why a mechanic would add smaller wire to an existing circuit is beyond me. #14 wire has half the amp rating of #10. I would start there to see if that does the trick. If it didn't, I would also measure voltage drop/resistance at the switch.

Regarding your alternator question, I did exactly what you're saying. I have a second alternator hooked up just for the starting battery. I have a 10si hooked up in that spot with an internal regulator. My house bank is charged by a souped up Leece Neville (sp?) that looks just like a 10dn delco and is rated at 105 amps. I carry a $70 Delco 10DN externally regulated spare that I can use to replace either alternator if one fails. Just plug it in on the house side that is already wired for a smart regulator, or plug it into the starter battery side and use a $15 napa external voltage regulator. I personally don't have a problem using an automotive alternator on a diesel engine. You're not going to get the amps out of your replacement alternator though unless you have a fancy external regulator. Also, while those alternators will run on one belt, it really is pushing it.

[poopdeckpappy]

Sawingknots, the soleniod is new and works fine everytime I test it in the slip, the way this one works is, the soleniod is linked to the injector pump, one wire lead goes from the soleniod to the stop bottom and another from the soleniod to the Alt, when the buttom is pushed the soleniod plunger retracts pulling a fuel shutoff arm at the other end of the linkage. I'm thinking that this new wire install could be an issue or my alt could be headed south. Why this wire was used I have no clue, other than it may have been what he had on hand, had I known, I would have ran to the shop for him, @ 90/hr/ 2 hr min it's the least I could do

Erps, I'm going to look into this more, the part No. on the Alt case matches what GM put in their big block car & trucks and large sadans with heavy power usage due to all the options, they mention high charging at low rpm.

At 125.00 a pop and somewhere around 100amp ?? I think it's worth a look see, and I can't imagine the environment which it's being use now could be worse than street use

[erps]

Sounds like the alternator wire is the power source and then the wire that runs to the shut of switch is a path to ground to energize the solenoid. That terminal should measure around 14 volts when the motor is running.

Is that alternator you're looking at internally regulated? They suck for deep cycle batteries, but I've seen instructions on the internet that shows how to open up the case and do some modifications to allow for an external regulator.

[poopdeckpappy]

Yes, the ones I'm looking into are internal and the one I have now is internal, I have all the orignal plans with addendums, it originally had the Delco starter & 10si alt, whats funny is, one addendum change the black wire to a #10, but from what I don't know

I'm thinking that new wire is the problem, will find out shortly

[flatracker]

Not going to comment on the solenoid problem, not sure I know enough about what is going on to make a sensible comment. However, on the alt. I can make more than an educated guess. Go to any auto supply, and get yourself a rebuilt, with a lifetime warrant. No muss, no fuss. I believe the alternator you want is a Cadillac, early model. Believe they are 100amp. Possibly a bit more than that. If you go in without having a make, model and year, many of the counter guys will just give you a stupid look. Tell you they ain't got it. If you have a good local alternator shop, they can take one look and give you an exact make and model.

[poopdeckpappy]

Originally Posted by flatracker

I believe the alternator you want is a Cadillac, early model. Believe they are 100amp.

1983 Cadillac Fleetwood 5.7L MFI Diesel OHV 8cyl

Notes:
Manufacturer:	Delco Remy Premium reman
Alternator Amperage:	100
Pulley:	1V
Regulator Plug Clocking:	12:00

[donradclife]

take a digital voltmeter and measure the voltage across the solenoid when you hit the switch, and compare it with the voltage across the battery terminals. Do this first with the shorepower on and engine off. Then turn the shorepower off and turn on about 10 amps of load (running lights/radar/etc) for 20 minutes and do it again. Then start the engine (lights on/ shorepower off) and do it a third time.

The first test should tell us how bad the wiring is to the solenoid. The second and third tests will tell us whether the alternator is toast, and whether that wire from the solenoid to the alternator is part of the problem (you don't have a battery isolater do you??)

[poopdeckpappy]

Thanks Don you made that sound easy, I've been trying to remember who has my meter so I don't have to get another...... hate it when I do that

No Batt isolater either