Flashing Gen Lights (Both)

[deercoker]

These flashing gen lights did not start till cold weather and my glow plug relay as well as 6 of my glow plugs were bad and she would not not start, the batteries were on it when I bought a couple weeks before all this and they look brand new, anyway I ran them down trying to get it started and had to charge them twice until I figured out the relay and glow plugs were bad, after replacing them she starts right up but now the gen lights flash, I used a cheap load tester from harbor freight and the batteries checked ok but I think I might drive it to autozone and have them check my batteries just in case, I would presume that bad batteries would also cause an overcharge issue, am I correct in thinking that?

 

[Rvitko]

The opposite is more likely, bad alternator would overheat the batteries and boil out the water, in a really bad overcharge the batteries will balloon and may even blow up. If your battery is not sealed and you can remove the caps and check the fluid level, if it is low, that further points to overcharging. Since it is the driver side alternator, you can use a regular 27SI from autozone, but since it is not isolated ground, be sure to never swap it with the passenger one and I would keep your core and just pay the core deposit. The original if it is an AC Delco is worth more than the deposit. I think if you get into it, you will see how easy it is, there is plenty of walkthroughs and pics on this forum, Warthog in particular has some great posts on the topic. Outside of the bearings, it is just turning screws and replacing parts, changing glow plugs is a much worse job.

 

[deercoker]

Yea my batteries check fine with a load tester so I am probably looking at buying a new drivers side and rebuilding the passenger side,

Thanks

 

[deercoker]

just seems strange that both gen lights start flashing after the glow plugs, relay were changed and I bypassed the resistor, I also pulled the card get a visual which was a pain in the butt, I think I may have pulled the firewall wiring thru plug loose when I did it, any chance a short or bad ground in that area would cause the overcharging? I promise I will quit guessing I am just trying to rule out the simple stuff before throwin more money at it,

Thanks

 

[deercoker]

Alright fellars, my drivers side is putting out 15.1 volts after idle down so I think I will go ahead and replace, the Autozone P/N DL7157 which according to the threads is an adequate replacement at 78 amps, however according to Autozone the DL7157 is a 100 amp alternator and they say it will not fit according to them, who's right, any ideas before I order, I really have tro get this puppy on the road,

Thanks

 

[dependable]

Delco SI 27, isolated ground. 100 Amp. Your alternators should be of same output, so the 78 amp is not so good. Auto parts chain stores are not a good place to get info for the electrical parts of the CUCV. They usually have no clue.

You could try 'rebuilding' the alt, parts kits are available pretty cheap if you have a work bench and some tools. You may just need a voltage regulator.

 

[deercoker]

I most likely will rebuild the pass side if bad, my understanding is the autozone DL7157 is a good replacement for the drivers side as it is not a required isolated ground and is actually grounded to the engine even though both originals are isolated ground for stocking purposes, previous threads had said the autozone one was 78 amp but they show it as 100 amp, My last M1009 had been converted (poorly) to 12 volt and the alternator on it was bad when I bought it so I used the autozone one and it worked fine for 2 years till I sold it, now I have bought another M1009 still 24 volt and the drivers side is putting out alittle (15.1 volts) to much juice so Figured I would change it,

Thanks

 

[Tow4]

I most likely will rebuild the pass side if bad, my understanding is the autozone DL7157 is a good replacement for the drivers side as it is not a required isolated ground and is actually grounded to the engine even though both originals are isolated ground for stocking purposes, previous threads had said the autozone one was 78 amp but they show it as 100 amp, My last M1009 had been converted (poorly) to 12 volt and the alternator on it was bad when I bought it so I used the autozone one and it worked fine for 2 years till I sold it, now I have bought another M1009 still 24 volt and the drivers side is putting out alittle (15.1 volts) to much juice so Figured I would change it,

Thanks

If the alternator is working at all, I would suggest you rebuild the stock alternator. Isolated ground alternators are hard to come by.

My signature has a link to my alternator rebuild thread and also my classified add for the rebuild kit.

 

[deercoker]

The core is only $12.00 so I will keep and rebuild it as a spare for either side, I think that makes the most sense as I need to get this thing on the road by Sunday, I would keep driving as is but I do not want to swell my batteries. How can you tell if the drivers side is an isolated ground unit and not been replaced, can you tell just by looking at it?

Thanks,

 

[Tow4]

The core is only $12.00 so I will keep and rebuild it as a spare for either side, I think that makes the most sense as I need to get this thing on the road by Sunday, I would keep driving as is but I do not want to swell my batteries. How can you tell if the drivers side is an isolated ground unit and not been replaced, can you tell just by looking at it?

Thanks,

You can tell by the extra terminal on the back for the ground. It is similar to the B+ terminal except the insulator is black.

 

[deercoker]

Well I just installed the Autozone Delco-Remy alternator on the drivers side and now have 14.7 volts out and 29.6 across both batteries which means I think that the passenger side is putting out 14.9 volts which I believe is a little high, I will drive tomorrow and see if the gen lights are still flashing. On a side note the voltmeter gauge has not worked since I bought her but after the drivers side alternator change it goes to red when you turn the headlights on, so it appears I still have a gremlin somewhere,

 

[deercoker]

Drove it to church and back this morning and no flashing gen lights! yippee! now on to the voltmeter