Water crossing bat light on

[HRH]

So I took the D21 out tonight in the freezing cold of Airway Heights (about 30-32ish) to check out a potential rallycross site. Followed a dirt two track though the field and ran into a few puddles. Not huge puddles mind you, but enough to splash water around. And of course I had the heater at full speed and brights on. When I hit the water, the lights dimmed and the blower motor slowed down, and out of the water gave it a few seconds or so and they lit back up brighter and the blower motor speed increased back to normal.

 

Then went through a longer section and got the battery light to come on. Even after stopped on dry ground it took a full minute or more to right itself.

 

Now, I'm aware that flooding electrical can cause issues like this, but I drenched the shit out of the 720 in mud holes before and never had any alternator issues. My belt is tight on the hardbody. The alternator is rather in harm's way as I don't have the fender rubber that hides it, so literally the water splashes right onto it. I don't know if I just never had any accessories on in the 720 to notice the electrical draw of the alternator not working briefly and running on battery, or if for some reason it was a better alternator.

 

Wait a moment! As I typed that, I just though of something. The 720 alternator was almost entirely enclosed on the sides, you couldn't see the windings, whereas the D21 alternator is very much exposed on the sides with lots of venting. I wonder if that could be one of the issues?

 

Anyway, my whole idea is to make water crossings not dim the lights. Any suggestions? Higher waterproofed alternators? Other tricks to prevent shorting, short of sealing the engine compartment? I may start with finding the rubber shielf and putting that back on, but I hate having it on because it's a bitch to get at the oil filter unless it's off.

[izzo]

All of my datsuns do this when i go thru puddles, it usually caused by water getting inside the alternator. after a few seconds it pops back up to normal. no expert, not sure if its the same for you.

[datzenmike]

It's either the belt slipping or water on the brushes. After a short while it starts working and is fine. I've had this with power steerring too, suddenly it'd armstrong steering and then back again.

 

If it's just spray then get some kind of guard on it, don't forget the fan will force it back onto the alternator as well as direct splash. Try a better belt too. If you are submerging it, then there's really no way to prevent it.

[HRH]

Pretty sure it's water in the brushes, especially taking so long to get the bat light off. Think maybe I'll make a guard for it. I'd like to put it where the power steering pump is now, but that seems like a lot of work. Here's the funny thing though, Buddy has sunk his Wrangler in lots of puddles and it hasn't happened to him. I wonder if the alternator is mounted up higher on the 4.0 liter?