Hello all. I have a 95 Dolphin rv f53 engine (460) that I have finally got running. The other day I have discovered that the alternator is going out. As soon as I start the engine, acid starts to come out from under the caps and I can hear it boiling! I tested the voltage and found that the alternator is putting out 19 volts! I looked on the alternator and I didn’t see any markings as to the amp output. Without having to take it out which I’m going to have to do anyway, does anyone know what amp size this make and model RV takes? My research says 90-130 amp.
Alternator replacment
- Thread starter Liuhisn
- Start date
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John From Detroit
Well-known member
I would go with the larger one but the amp rating will be stamped on the frame.. Likely where you can not reach it.
Now there are two or 3 alternator designs... Many modern ones it's all internal. in fact some (And Ford uses this design among others) have only one wire hooked to them.. Others have 2 or 3 wires and some have external voltage regulators.... IF yours is the latter. that's your problem. the Voltage Regulator. However I think those are rare these days.. But I go back to before alternators.
Now there are two or 3 alternator designs... Many modern ones it's all internal. in fact some (And Ford uses this design among others) have only one wire hooked to them.. Others have 2 or 3 wires and some have external voltage regulators.... IF yours is the latter. that's your problem. the Voltage Regulator. However I think those are rare these days.. But I go back to before alternators.
Kirk
Well-known member
The maximum current output doesn't impact that output voltage but in an RV, for current more is better. The higher rated alternator will cost more but it will also recharge your batteries much more quickly. My 1998 Cruise Master(99 F53 chassis) came with a 130a alternator.
Gary RV_Wizard
Site Team
Make sure the alternator has its voltage feedback wire connected and correctly reflecting the system voltage. That is what drives the voltage regulator inside the alternator. Typically the feedback wire comes from the ignition switch terminal. Basically, the internal voltage regulator monitors the voltage coming out of the alternator and adjusts to keep it in the range 13.5v-14.4v.
If you want to learn more about alternators & charging, try this online article.
If you want to learn more about alternators & charging, try this online article.
JayArr
Well-known member
It doesn't matter much what the existing one is, buy the one with the most amperage, that you can afford.
They are going to want yours in exchange so the easy way to replace an alternator is to remove it and take it to the NAPA/PepBoys/Summit and give it to the counter-person. They'll get you an upgrade and you can check that it's the same for mounting and wiring before you leave the store.
They are going to want yours in exchange so the easy way to replace an alternator is to remove it and take it to the NAPA/PepBoys/Summit and give it to the counter-person. They'll get you an upgrade and you can check that it's the same for mounting and wiring before you leave the store.
Thankyou! The old and new alternator have one red wire and two plugs that plug into the alternator. A poster on another site mentioned a “sense” wire that was lost between the battery and the alternator. Either way, I’m going to have to climb underneath and trace wires and or look for an external voltage regulator. Any more tips and pointers will greatly be appreciated.
John From Detroit
Well-known member
Well as I said (i think) most modern alternators the regulator is "internal" but I go back to a time before alternators and back then all of them were external. and with the early alternators they were as well.
The 3 wires. The big one is "Battery
The other two are Sense (Hooks to the heavy battery cable close to the battery) (may be labeled "S") and
Field (may be labeled I or F) This is the wire that energizes the alternator at lower RPM via the Idiot light.. Once the alternator is spinning fast enough to self energize. the light goes out because the voltage on both sides.. the same.
The 3 wires. The big one is "Battery
The other two are Sense (Hooks to the heavy battery cable close to the battery) (may be labeled "S") and
Field (may be labeled I or F) This is the wire that energizes the alternator at lower RPM via the Idiot light.. Once the alternator is spinning fast enough to self energize. the light goes out because the voltage on both sides.. the same.
House Husband
Well-known member
As delivered from the Ford Factory, you F53 chassis came with a 2G 130 amp alternator with attached regulator on the rear. The included link to a wiring print should allow you to trouble shoot your problem.
Ford 2G alternator & regulator wiring print.
Richard
Ford 2G alternator & regulator wiring print.
Richard
Hello I posted a few days ago about an alternator overcharging. Well here is an update to the situation. I removed the new alternator and took it in for testing after crawling around underneath the rig looking for loose and frayed wires. It passed with flying colors,14.3v! This then begs the question, why is it overcharging?! Well a call to RVworld and a description of what is happening along with year make and model. I was told that there is a secondary voltage regulator somewhere in the engine. Apparently in the 90’s this was a common practice. Relieved that is is not something major, I just have to find it! If anyone knows where the possible location of an external voltage regulator in a 96 Dolphin Rv I would appreciate it. Dealing with people getting sick so I don’t have a lot of time.
Ex-Calif
Well-known member
As Spencer says, it won't be far away and most likely will have 3 terminals on it.
Mark_K5LXP
Well-known member
Wow, that looks like a point regulator for a generator from the '60's. I don't think that's it...
I know Fords back in the day had external regulators but even as late as '95? I know my '99 didn't.
Edit: My '95 ranger has an external regulator so not a stretch to believe the truck chassis would.
Mark B.
Albuquerque, NM
I know Fords back in the day had external regulators but even as late as '95? I know my '99 didn't.
Edit: My '95 ranger has an external regulator so not a stretch to believe the truck chassis would.
Mark B.
Albuquerque, NM
Ex-Calif
Well-known member
You're right - It could be an I/C type external regulator but who knows?
Gary RV_Wizard
Site Team
Possibly one like these...
However, if the alternator has its sense wire connected, I don't see how an external regulator could increase voltage above what the alternator is putting out. Basically a limiter, not a transformer. But if the sense wire is not connected, or is sensing from a low voltage source, then the alternator will drive high and 19v is possible.
However, if the alternator has its sense wire connected, I don't see how an external regulator could increase voltage above what the alternator is putting out. Basically a limiter, not a transformer. But if the sense wire is not connected, or is sensing from a low voltage source, then the alternator will drive high and 19v is possible.
