M934A2 Alternator Swap Verification Question

[Gunny65]

l am converting my M934A2 into an RV. I have already swapped the four starter batteries for two group 31 batteries. I have run 4/0 wires from the batteries back to the rear of the Van portion to charge the house batteries with the alternator (I also have a battery isolator/charger inline). I have also replaced the stock 60 amp alternator with a 160 amp Alternator. I have also upgraded the cables from the starter to the batteries. I am thinking about running a #4 wire from the power lug on the new alternator to the starter. I am concerned about the ABS and the battery cut off switch. By not hooking 568 and 566, the two small wires that were hooked up to the old alternator, will it affect the ABS and the make the battery cutoff inoperable?

So, my question is: if I tape off 568 and 566, will it affect my ABS, battery cutoff switch, or anything else that may be important?

I have pictures if needed.

 

[FullSpecial]

That is what I did. I have found that going to a high output 24v Delco it needs about 1300rpm to fully come alive.

 

[FullSpecial]

I should add leave the current output wire on the alt, you will have power on both sides of the run relay of the PCB and not need to use the Battery switch on the dash if you are using a separate cut off switch.

 

[Gunny65]

Looks clean. Nicely done.

Is that a hot cable running directly to the starter from the bottom alternator? Where is the top alternator's hot wire going? Just curious.

It looks like you have the 568 wire (the one with the waterproof plug) connected. Is that the "current output wire" you are talking about? If so, where is it connecting? It looks like maybe to the main power terminal on the top alternator? Attached is a pic of 568 still connected to the old alternator.


I have the new alternator hooked up now. However, the alternator gauge on the dash is showing in the yellow continuously unless I rev the rpms, like you noted. The batteries are being charged but the gauge now makes it look like the batteries are low. Not sure why but I think it is because I have not put in a larger gauge wire yet? The second pick shows the original starter wire hooked up. That is the only reason I can think of as to why the gauge is showing in the yellow when I put power to the truck system but have not started the motor yet. Never did that before.

OH! it just came to me. Is one of those wires I do not have hooked up a signal wire from the batteries?

 

[FullSpecial]

1Q: Yes
2Q: 5th battery, separate 12V system. [toys]
3Q: Waterproof connector is the temp sender, It's behind the bypass hose. Output wire looks correct in your photo.
4Q: My red 4g wire from alt output to large stud on starter with cable going to batteries.
5Q: No, my green wire is the ground to modified temp sender.
6Q: No. Windings in higher output alts just need to spin faster to make them work, just the way it is.
Point of order, Power output wire on the starter, [factory] goes to the power control box and the battery relay.
Power goes through the relay and back to the large stud on the starter when running. Look for posts about the PCB.
7Q: Yes BUT, most Delco alts do NOT need an excite wire. Tape it off.

 

[Gunny65]

One more, hopefully, question.

Would it hurt to run an additional (heavier gauge) wire from the alternator output to the starter? I would think that would help with amperage going back to the house batteries.

I want to keep the wiring going through the PCB but still have full amperage from the Alt to the house batteries.