Overdrive electrical troubleshooting (was: Fuse for overdrive)

[Young Ed]

My overdrive has something wrong with it and blew the fuse. The one I took out was an SFE 30. The book however calls for an 20amp. So I went and got a SFE20 but that one is too short to remain tight in the holder. What # am I supposed to be using???

[james curl]

you should be able to get long fuses in 20 amp at most auto parts stores.  They come in two lengths if I remember correctly.

[Mark D]

It seems that alot of the older style glass tube fuse holders where shorter than the modern equivalent.  Interested to hear what is causing the short.

[Plymouthy Adams]

for the time I would consider putting in a 20 amp circuit breaker for troubleshooting the cause for the increased amp draw..you will need to break the circuit at various junctures to place the amp meter in line for a reading ...remember ohm's law in determining what the current should be at any given point...and sadly you nned to have known the original value say of a solenoid prior to possible internal shorting of the coil internally as a comparasion..if you have other OD's do read these on the bench

 

fuses..try AGF for the longer glass fuse..

Edited October 23, 2014 by Plymouthy Adams

[Don Coatney]

Easy to replace the fuse holder and use the 20A fuses but if it blew a 30A fuse it will certainly blow the lower amperage fuse. Best to find and fix the problem first.

[Dave72dt]

SFE fuses vary in length by amp rating, AGC fuses are all the same length and a replacement fuse holder normally comes with several springs in it to accommodate different length fuses. Fuses will also vary by type of reaction, some react fast, some a bit slower for absorbing a shock load.

[Plymouthy Adams]

Ed..in troubleshooting this  you need to keep in mind12 volt verse 6  I am not sure if you are still 6 or not..but if you are 12...granted the current is going to increase due to ohm's law VR=I and thus you will have to compensate for this increase in current with the larger value fuse...

[Young Ed]

  On 10/23/2014 at 2:05 PM, Dave72dt said:

SFE fuses vary in length by amp rating, AGC fuses are all the same length and a replacement fuse holder normally comes with several springs in it to accommodate different length fuses. Fuses will also vary by type of reaction, some react fast, some a bit slower for absorbing a shock load.

The relay doesn't use a coil spring. The tab that the bottom of the fuse rests against springs up and down for the fuse. I will try for an AGC.

 

  On 10/23/2014 at 2:40 PM, Plymouthy Adams said:

Ed..in troubleshooting this  you need to keep in mind12 volt verse 6  I am not sure if you are still 6 or not..but if you are 12...granted the current is going to increase due to ohm's law VR=I and thus you will have to compensate for this increase in current with the larger value fuse...

 

Thanks I'm still running 6v.

  On 10/23/2014 at 1:01 PM, Don Coatney said:

Easy to replace the fuse holder and use the 20A fuses but if it blew a 30A fuse it will certainly blow the lower amperage fuse. Best to find and fix the problem first.

 

Yes I believe after following the troubleshooting steps that the solenoid needs the internal contacts/points cleaned. If that doesn't do it the next step says replace solenoid.

[DJ194950]

Ed, if you already haven,t done so look in the reference area-downloads- 5th. one down is a solenoid for borg-warner OD repair info.

 

DJ

[Young Ed]

  On 10/23/2014 at 8:37 PM, DJ194950 said:

Ed, if you already haven,t done so look in the reference area-downloads- 5th. one down is a solenoid for borg-warner OD repair info.

 

DJ

Thanks for telling me that!!! I wasn't aware it was there and it was very helpful. This is what I found. The plunger does move freely by hand if I pulled on it. The battery charger I have wouldn't do anything with it. I followed all the steps to clean it up and still nada. The negative just sparks when put to the #4 terminal.

 

 

[DJ194950]

No sure that a battery charger has the amps to do the job. A battery?

 

Time to do a good cleaning  and maybe some ohms checks? Make sure the piston?plunger moves to the contacts that  lower the amp draw to Hold v.s. Pull.  All per my reading not really my specialty!

 

DJ

[Young Ed]

  On 10/24/2014 at 1:23 AM, DJ194950 said:

No sure that a battery charger has the amps to do the job. A battery?

 

Time to do a good cleaning  and maybe some ohms checks? Make sure the piston?plunger moves to the contacts that  lower the amp draw to Hold v.s. Pull.  All per my reading not really my specialty!

 

DJ

 

Even after the good cleaning it still wouldn't do anything. Plymouthy walked me through reading the ohms. Got 119. Tomorrow I will try it with a battery and do some comparison to the other one I have.

[Young Ed]

I did some comparison with the other one I had and it seemed like it was ok. Battery charger didn't have enough umph to operate either one so I used the battery and both worked. So I put the existing one back in. Went for a drive and the OD worked. Today I got about 45miles into a 120 mile ride and suddenly the OD kicked out never to work again. So in spring it will be back to the drawing board.

[Don Coatney]

Is your charging system working?

[Dodgeb4ya]

I'd try the other solenoid you have.

[Young Ed]

  On 10/26/2014 at 3:03 AM, Don Coatney said:

Is your charging system working?

I believe so. Car has been starting all summer long.

 

  On 10/26/2014 at 3:12 AM, Dodgeb4ya said:

I'd try the other solenoid you have.

I will. Just wanted to avoid robbing that OD of its solenoid if I could.

[Don Coatney]

Forum member Richie from Atlanta was driving his OD equipped P-15 somewhere in the New England States when his Generator quit. First indication was his OD quit working. He repaired the Generator and all was well with the OD for the rest of the trip. So low voltage can be an issue.

[Plymouthy Adams]

you original chat reply back to me on the 85 and 119 ohm readings are throwing a kink into the mix...it should not be this high..if this high odds are you have a resistance issue within the contacts or a very bad connection in the wiring..clean all contacts and check connections for clean and tight ..last word was you were going to clean the unit up inside..DO inspect the very fuse holder itself for corrosion..as an added note..the body of the solenoid I think on the Mopar R10 is the ground path..make sure it is making a clean connection to the tranny also..an added  ground jumper may be in order if mounting surface of the solenoid is showing signs of excessive pitted surface

 

if your unit was shorted inside (wires melted together), it would read less than the 3.22 ohms that by current draw rating dictate it to be..I am basing that only on ER=I and the factory rating of 20A fuse..

Edited October 26, 2014 by Plymouthy Adams

[Uncle-Pekka]

Ed,

I had the same problem with my 1951 Nash B&W OD when I first got the car. It kept blowing the fuse. When I pulled the solenoid the contacts were in bad condition. I cleaned contacts but the problem continued. As I opened solenoid end cover again the hold contact was burn. I replaced it by riveting new contact on the burn exisiting. Still no progress. At this point I replaced solenoid.

 

Afterwards I took the original solenoid to an auto electrician. He told the hold coil was defect. (insulation burn, I take it?)

 

I am not saying yours has to be the same problem as mine, but the symptoms appear the same.

 

Also Tim's above suggestion makes sense: In case there's a bad or corroded connection some where along the circuit, it will load the fuse (& entire system).

/Unkka

Edited October 26, 2014 by Uncle-Pekka

[DJ194950]

A thought although probably the least likely is does the face mounting area to the tip of the plunger measure 1 " when not activated?

 

Some other brands of cars/trucks using the R-10 trans measured 1 1/8" or 1 1/4" Large mounting flange face to the tip. Wrong solenoid length would prevent the plunger from full stroke and maybe prevent enough travel to engage the holding coil and still be on the pull coil windings. Hope this makes sense.

 

DJ

[meadowbrook]

I suppose I can appreciate my R7 unit more now. My solenoid works in the opposite way, it only activates to DISengage OD, so I guess it is under less stress. It is smaller.

[Young Ed]

Swapped in the solenoid from the other OD and drove 120 miles home from storage today with no issues. OD went in and out as I went through towns or slow downs.

[Mark D]

I'll be in the shop Tuesday evening debugging mine.

[Plymouthy Adams]

check that tranny close..may be a hair ball issue..PP still not found that cat yet..