Alternator issue...

[Guffey6]

Alright guys, my 88 7.3 is driving me MAD! If its not one thing its 10 others. My new issue is the alternator. I've owned the truck about 5-6 years now and this will be the 3rd alternator i've put on it, If i decide to go that route. The batteries have been weak for the past few weeks and twice this weekend i've had to jump start it, been too busy to troubleshoot until today. However, while the SOB is running im only getting 12.26v at the alternator output, should be reading around 14.4v, correct? Replaced the voltage regulator a couple years back but i dont see that being the issue. So... tell me more about the 1G swap? or 3G cant remember, and where to get one. I want a new one so pulling one is not an option. What model and such should i been looking for? 8.25 hole spacing, correct?


PS.. another issue but i did the facet swap a couple of years ago and im having an issue with a fuel leak, minor yet causing low fuel problems while towing. has anyone had this issue? its leaking at the brass connectors and causing the fuel filter light to come on while towing up hill. I changed the filter last weekend to find it was 3/4 full, or if your pessimistic 1/4 empty, which made me look further. Reason for asking is that i've tightened and re-tefloned and it keeps loosining up... This dang truck will be the death of me! Somedays i feel like i can take her on a cross-country sightseeing tour and others, well i dont trust her to get to the mailbox. Thanks in advance for all your help.

 

[Macrobb]

Alright guys, my 88 7.3 is driving me MAD! If its not one thing its 10 others. My new issue is the alternator. I've owned the truck about 5-6 years now and this will be the 3rd alternator i've put on it, If i decide to go that route. The batteries have been weak for the past few weeks and twice this weekend i've had to jump start it, been too busy to troubleshoot until today. However, while the SOB is running im only getting 12.26v at the alternator output, should be reading around 14.4v, correct? Replaced the voltage regulator a couple years back but i dont see that being the issue. So... tell me more about the 1G swap? or 3G cant remember, and where to get one. I want a new one so pulling one is not an option. What model and such should i been looking for? 8.25 hole spacing, correct?

If you keep the current alternator, have it checked out and then re-wire the wiring between it and the regulator. If still nothing, replace the regulator and make sure it's well grounded(case of regulator).
A 3G swap, well, just find an alternator that measures the same bolt-wise as your current one. Wiring on those is easy.

PS.. another issue but i did the facet swap a couple of years ago and im having an issue with a fuel leak, minor yet causing low fuel problems while towing. has anyone had this issue? its leaking at the brass connectors and causing the fuel filter light to come on while towing up hill.

No, that's not it. If the fuel filter light comes on, you are creating a major vacuum in the fuel filter. This means negative pressure. You want to be looking for a restriction somewhere, not a leak. A leak will allow air in, instead of drawing a vacuum.

I changed the filter last weekend to find it was 3/4 full, or if your pessimistic 1/4 empty, which made me look further.

This means air is getting in pre-lift-pump, most likely.

Reason for asking is that i've tightened and re-tefloned and it keeps loosining up...

Uh... you mean the brass connectors that seal with an "olive", or NPT threads? You don't use teflon on *anything* but NPT(tapered) threads.

 

[Guffey6]

@Macrobb its the NPT threads. an electric fuel pump. i completely removed the old lift pump mechanism. So if im pumping fuel electrically, the restriction has to be between fuel pump and filter? or would it be filter to IP? or could the IP be taking a dump on me? or could a slow pump, not being able to keep pressure, create the vacuum?

 

[chillman88]

I would expect a facet pump to be more than adequate as in should be PLENTY of flow. How old is your pump? The filter light is in the filter head so what's happening is the IP is trying to draw more fuel than is available. I would imagine the restriction could be anywhere between the tank and the filter at this point. Are you having any issues with your tank selector valve? It just seems odd to me that a new filter didn't help.

Just for giggles, is it possible there's a kink in a fuel line? I doubt it but I'm very good at missing the obvious so I'm just asking.

 

[tradergem]

This diagram will help if you decide to go with a 3G alternator.

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[crash-harris]

For finding a large case 3G alternator, grab one for a '93 E350 with a 4.9L. The larger case fits better if you're still using the V-belt setup and have the 2 bolt alternator setup. Some write-ups have mentioned having to grind a little on the case for the dual v-belt pulley to fit, but every one I've tried, the pulley has fit just fine without the washer between it and the nut. I just use the new alternator's nut, hold it worth an old belt and hit it with an impact.

 

[retiredinhomer]

My 92 7.3 e350 has the two pulley 3g alt. My spare is from db electrical but it has the serpentine pulley so I pulled the pullley and will have to change pulley's.
I carry a lot of spare parts for the annual run back to Alaska.

I bought this one https://www.dbelectrical.com/produc...ickup-86-89-bronco-86-89-crown-vic-87-91.html

 

[jayro88]

I have had to replace the alternator on my ‘88 e250 7.3 a few times. It is under warranty so it doesn’t cost me anything except the time. Problem is it never happens when I am close to home, so I am usually stuck doing it in a parking lot somewhere. Not to mention it usually isn’t a stock item.

This summer I am going to swap in a new 3G and hope it is the end of my issues. Plus the 1G/100amp doesn’t keep up with charging the batteries when both ac blowers are going at idle.

I purchased a voltage gauge that plugs into my 12v outlet so I can see that it is dead long before it leaves me stranded.


Sent from my iPhone using Tapatalk

 

[whiteboyslo]

If you need a dual v-belt, this is the PN for one that comes with the pulley and is clocked correctly. 7756-3N-2G

All you need is a new upper mounting bolt and washer, plus the usual 3G wiring stuff.

Mike