Battery/start solonoid questions

[Bilito]

I keep going thru solonoids, they fail engaged and I gotta hop out and bang on them with a hammer to get them to release, (if I turn the key off and they keep cranking) what can be causeing this.
I turn the key to start, the starter tries hard to turn motor over and once it turns once then it turns good and motor starts, seems like a big load right at the start.
What do you electrical guys think??

I was thinking maybe the battery don't have the oomph to crank the 454

[Dave78Chief]

Let me see, did you get a new rig? I thought you had a Oshkosh chassis with a Ford 460 not a GM P30 chassis with a 454. You gotta give the right information to get the correct answer.

Assuming 460, Are you talking about the actual Ford Starter Relay or is this a Aux Battery relay?

Ford Starter Relay:


Aux Battery Relay (Normally NOT in starter circuit)


Dave

[Bilito]

Originally Posted by Dave78Chief

Let me see, did you get a new rig? I thought you had a Oshkosh chassis with a Ford 460 not a GM P30 chassis with a 454. You gotta give the right information to get the correct answer.

Assuming 460, Are you talking about the actual Ford Starter Relay or is this a Aux Battery relay?

Ford Starter Relay:


Aux Battery Relay (Normally NOT in starter circuit)


Dave

It's a ford 460 I got confused with the numbers.
The solonoid failed again today, this is the 5th time, also the second time it blew the 20A IGN fuse which controls the fuel pump and the engine ac.

The battery is a pretty new (still under warr) It's a group 24 West Marine 460 starting battery which has 550 MCA (marine cranking amps) I was wondering if it just did not have the power to crank this big motor and is overheating wires and everything when I start it up. It was an extra battery in a boat I sold that had a 135 hp Volvo 4 cyl motor, I never put it in the boat.
The starter was rebuilt by a very reliable rebuilder here in Miami.
The first 3 solonoids I got at auto zone the last one's I got at NAPA they are supposed to be heavy duty. I have only seen this happen once before on a 68 mustang 289 that belonged to a friend of mine. I changed the thing for him and that was that.
waddayathink?

[BA-in-Mich]

[QUOTE=Bilito
I turn the key to start, the starter tries hard to turn motor over and once it turns once then it turns good and motor starts, seems like a big load right at the start.
What do you electrical guys think??

I was thinking maybe the battery don't have the oomph to crank the 454[/QUOTE]
What do you mean the starter tries hard? I have a 900 CCA battery on my 454. A little story about my 1990 chevy pu. It has the 4.3L 6 cylinder. The thing for years would crank like the battery was just about gone even with a new one in it. Long story short it wound up being a bad ground wire between the frame and the engine. The old one rotted off. The funny about this is the ground from the battery was rock solid on the engine and to the body and same for the wire going to the starter. From what I can surmise the starting current was too much on the solinoid and the body was somewhat isolated that it couldn't work properly to start the starter

[EngineerMike]

Sounds like you are over-amping the solenoid, and arcing/welding the contacts.
Electricity draws, does not "push." You could put in a 10X battery size and the draw would be the same.

Your starter could be bad, could be bad starter alignment so the bendix drive gear is pinching its teeth in the flywheel gear and making the motor hard to turn. I kept burning up fan motors on my air conditioner at home; put an amp probe on the fan motor & it was drawing about 35% more amps than it was designed for. turns out my fan blade is too "big" for that size motor, so in order for the motor to "draw" sufficiently to make the design RPMs, the motor overdrew its capacity and burned up the internal run capacitor. Your starter is DC so it doesn't have a start or run capacitor, but if its overtaxed you will pull more amps to get it to do the job. Could be wrong bolts installed on starter; some have knurled sections to create proper alignment when tightened. Could be shims were present in OEM install & someone left the shims out, so not proper starter alignment. Could be you have the wrong (undersized) starter solenoid (if starting is working fine, IIWMI'd probably order a solenoid w/higher amp rating and see if it works, can't be more than a few bucks difference; use your ohm meter to check the coil (small) studs on the original assuming you are not burning up the coils and get a beefier one w/same coil ohms so you don't mess up the low amp start circuit). Could be a partial short in the high amp start circuit; if you have a good amp probe (I have one w/hold-high-value feature that is good for this) then measure starter draw & post it.

[Dave78Chief]

I tend to agree with EngineerMike. For some reason you are drawing way to much current. It is the high current that is basically welding the solinoid contacts together. Could the timing be to far advanced such that the starter is fighting the engine?

Dave

[Bilito]

Originally Posted by Dave78Chief

I tend to agree with EngineerMike. For some reason you are drawing way to much current. It is the high current that is basically welding the solinoid contacts together. Could the timing be to far advanced such that the starter is fighting the engine?

Dave

how can I measure amp draw at the solonoid while cranking?

I charged the battery until my charger said it was full and shut itself down. I just barely touched the key and started right up

[Bilito]

Originally Posted by EngineerMike

Sounds like you are over-amping the solenoid, and arcing/welding the contacts.
Electricity draws, does not "push." You could put in a 10X battery size and the draw would be the same.

Your starter could be bad, could be bad starter alignment so the bendix drive gear is pinching its teeth in the flywheel gear and making the motor hard to turn. I kept burning up fan motors on my air conditioner at home; put an amp probe on the fan motor & it was drawing about 35% more amps than it was designed for. turns out my fan blade is too "big" for that size motor, so in order for the motor to "draw" sufficiently to make the design RPMs, the motor overdrew its capacity and burned up the internal run capacitor. Your starter is DC so it doesn't have a start or run capacitor, but if its overtaxed you will pull more amps to get it to do the job. Could be wrong bolts installed on starter; some have knurled sections to create proper alignment when tightened. Could be shims were present in OEM install & someone left the shims out, so not proper starter alignment. Could be you have the wrong (undersized) starter solenoid (if starting is working fine, IIWMI'd probably order a solenoid w/higher amp rating and see if it works, can't be more than a few bucks difference; use your ohm meter to check the coil (small) studs on the original assuming you are not burning up the coils and get a beefier one w/same coil ohms so you don't mess up the low amp start circuit). Could be a partial short in the high amp start circuit; if you have a good amp probe (I have one w/hold-high-value feature that is good for this) then measure starter draw & post it.

My son said to slide the starter out and check the starter gear for a wear pattern, it should show wear in the middle of the gear, not at either end. If it goes too far in it may be binding and need shims and too far out could mean wrong starter is in there. He indicated the starter gear is wider then the flywheel gear it engages. I never thought about that.

[Bilito]

Originally Posted by Dave78Chief

I tend to agree with EngineerMike. For some reason you are drawing way to much current. It is the high current that is basically welding the solinoid contacts together. Could the timing be to far advanced such that the starter is fighting the engine?

Dave

Dave I thought about the timing and I crawled under to look at that. The pointer is at the top and the only part of the timing pully I can see is the bottom. Wish there was a secondary way to check timing with a strobe light.

[Dave78Chief]

Engine has to be running to check timing with a timing light. I would have to research the how for the 460 engine.

I use a digital clamp-on meter from Sears to measure DC Amps (Digital Clamp-On Ammeter- Craftsman-Tools-Electricians Tools & Lighting-Multi-Meters & Meters). Lowes and such only carry AC clamp-on meters, not DC clamp-on meters. They are not the same. You have to use a DC clamp-on meter. The one from Sears is the least $ you will find.

[Bilito]

Originally Posted by Dave78Chief

Engine has to be running to check timing with a timing light. I would have to research the how for the 460 engine.

I use a digital clamp-on meter from Sears to measure DC Amps (Digital Clamp-On Ammeter- Craftsman-Tools-Electricians Tools & Lighting-Multi-Meters & Meters). Lowes and such only carry AC clamp-on meters, not DC clamp-on meters. They are not the same. You have to use a DC clamp-on meter. The one from Sears is the least $ you will find.

I gotta check with the backyard mechanics around me to see if anyone has that meter.
As far as the timing perhaps i can get in the wheelwheel and see the pointer and timing marks, if so I can talk to somei one insdie the RV., they can move the dist while I check the marks with my strobe. Thesee things just are not designed to have maint performed on them. What is the correct timing for this motor.

[Dave78Chief]

As far as what to set the timing too, there should most likely be an emmisions label on the valve cover or air cleaner that has the information. As far as how to set it on a 460 in a Oskosh chassis I am sure. Try posting that question over in the Ford F53 chassiis. Make sure you say it is a 91 (or is it 90) Oskosh Chassis with a carburated Ford 460. Many in that year range are Fuel Injected so you have to state things clearly. Hopefully Subford will see the post and can help you with setting the timing. He knows fords hardware real well.

Dave