Greetings everyone! Grateful to be a part of this forum. Also meet my truck...

[Cre8ivemindz]

I moved into a house in the mountains that came with this awesome 1988 Ranger that was modified to be a snow plow truck. I am still deciding on a name.

I am joining this forum because I will be the one working on this truck. There are no auto mechanic garages near me and the truck cant drive off my mountain because of the modifications. I am a carpenter by trade so I consider myself to be handy but doing mechanical work is somewhat new to me. I am excited to learn!

The truck and plow seems to be running well except for one issue that I am a bit stumped on. The cable between the alternator and the battery needed to be replaced. The cable was already removed when the truck was given to me. I replaced the cable but I am having an issue. From my research I am understanding that the alternator pushes a higher voltage than the battery can handle. So the cable needs to be hooked into a diode between the alternator and battery that adjusts the voltage before it hits the battery. I did not realize this and I had the cable going directly to the battery which ended up frying it.

So ... now I am having an issue finding the diode and I am not sure how it hooks into that circuit. If anyone could point me in the right direction I would be so grateful!



Also I am considering getting a better manual for the mechanics of this truck. Any suggestions would be greatly appreciated.

I look forward to being a part of this community and I hope to contribute as I learn more about this truck. Thank you!

 

[sheep herder]

The alternator has a built in voltage regulator. There is no diode between alternator and battery.

 

[pjtoledo]

maybe you could tell us a bit more about your alternator since something's "modified"

 

[Dirtman]

Hello truck!!!! Nice to meet you!!!


Oh and also tell your human hello as well...

 

[Curious Hound]

The alternator has a built in voltage regulator. There is no diode between alternator and battery.

Yes. This. If the alternator fried the battery, then the voltage regulator may be bad.

The alternator normally creates a voltage slightly higher than battery voltage. That is how it charges the battery. If the voltage goes higher than about 14.5 volts and stays there too long, it will kill the battery. A few minutes after starting, the alternator drops to just under 14 volts. @RonD has a great writeup on the charging system. I don't have a copy handy at the moment but its all over this forum in many threads.

 

[pjtoledo]

google or search: rebuilding car alternators

how-to's and parts sources

 

[Cre8ivemindz]

Excellent. Thank you all for your responses. I am looking into testing the alternator and possibly replacing if bad since the diode is built in.

pjtoledo: "modified" I meant that the truck was modified to be a snow plow. As far as I know the alternator was not modified. I am going to dig into alternator schematics next. Thanks for your input

 

[MaicoDoug]

Yes, watch that video!!!

Some basic stuff I'm sure that video covered,

While the truck is running, always be sure to never remove or re-connect the connection between the battery & the alternator ever. Test while the truck is running with a voltmeter (DC) across the battery posts, (not the connector) with nothing turned on. You should see the ~ apx 13.8 to14.4vdc charging voltage. You may have a shorted battery. What is the battery voltage sitting at rest? Say in the morning? Should be 12.6 vdc exactly sitting after a long rest for a good. Sometimes I will disconnect the positive lug, and probe for that magic 12.6 vdc after an hour or so rest.

To best troubleshoot the battery-alternator circuit, all voltage measurements that I am discussing are taken on the battery post only.

The battery's duty is to supply a huge amount of power to the starter and still have enough left over voltage to fire up the spark plugs at the same time. The only thing the alternator does when the motor is started is help keep the battery charged and especially recover from the load of starting the motor. This a simple scenario of the relationship between the two. The electrical connection between the two is normally a special "fuseable link" wire which is nothing more but a fuse. I believe this link ranges from 8 to 14 amps depending on the model & size battery.

The "frying" you see is that of the "fusable link" if I'm not mistaken. This is the "wire" normally between the two. Tell us what you find. Also perhaps post a picture.-Doug

 

[Curious Hound]

The only thing the alternator does when the motor is started is help keep the battery charged and especially recover from the load of starting the motor.

Not quite. During normal operations, the alternator feeds all operating loads and supplies a trickle charge to the battery. It does this by supplying a voltage slightly higher than battery voltage. Current flows from the higher voltage to the lower voltage. Since the battery is receiving power from the alternator, it is a load, not a supply. Battery just gets engine started and helps out when the demand for power exceeds what the alternator can supply.

 

[MaicoDoug]

I thought all loads start from a battery connection & go fused out from there. Well anyway I want to know more about that burnt wire. Wish we were both there to get her going.- Doug

 

[Curious Hound]

I thought all loads start from a battery connection & go fused out from there

As far as physical wiring goes, yes. But current flow isn't that simple.