98 Caravan AWD.....low voltage only at idle

[dx92beater]

Looking closer at Advance Auto's website, there are tons of alternators available for the vehicle.

I purchased the heavy duty 120 amp alternator back then as an upgrade.

It also looks like there are 2 pulley size options....65mm and 59mm.

It seems that I have the 59mm. I am wondering if I picked up the wrong alternator for the van when I replaced the first one and wondering if the first one was sized wrong to begin with.

I think if I got the 65mm one things would get even worse though no? So maybe I am barking up the wrong tree?

 

[dx92beater]

I finally got a member in the Caravan community to run some checks for me and they observed as indicated below.

So what I am experiencing is not normal for this vehicle.

Here is what they said:

Van on at stock idle, A/C on, Fan on High, Lights on, Wipers on High.

Just started first time this morning, 13.61 - 13.85 volts

After about 5 mins running: 13.23 - 13.36 volts.

With the Van on without A/C on, lights on.. it's closer to 13.95 volts if I remember correctly (I measured that last week).

 

[eljefino]

If you want you can temporarily wire up a voltage regulator for a dodge dart, just get a solid state one for a 1973 vintage. There are instructions online. Problem is you might get a CEL for computer not being in control any more. This will at least isolate your computer and its potentially wonky thought process though, and vindicate your alternator and battery as being competent.

 

[dx92beater]

Originally Posted By: eljefino
If you want you can temporarily wire up a voltage regulator for a dodge dart, just get a solid state one for a 1973 vintage. There are instructions online. Problem is you might get a CEL for computer not being in control any more. This will at least isolate your computer and its potentially wonky thought process though, and vindicate your alternator and battery as being competent.


Heh, not sure if you saw it but I tried that already. I wired up one for a 2nd generation Caravan, but to no avail.

 

[Cardenio327]

Originally Posted By: dx92beater
Originally Posted By: NHGUY
At low RPM you are running off the battery and not the alternator there.I have seen that happen when there is not a good connection between the battery and the cables/ends.Changing batteries in the past,I have had that happen and had to remove the clamps and clean/reattach the clamps.If you have "temporary" battery clamps and not soldered on ones I would suspect that as a problem.Use those cast type clamps and the solder slugs to permanently attach the two together.Works on my K...


I have never seen solder lug type battery terminals, would you mind posting a link if you know of one so I can see what they look like?

I use these on a few of my vehicles and have never experienced this problem so not sure that the clamps are the cause.

http://shop.advanceautoparts.com/p/autoc...ttery+terminals


I worked at a Napa fresh out of high school, when we sold these we always warned the customers that these terminals are for temporary repairs only.

You can get real solderable terminals at stereo shops, truck repair shops, starter/alternator rebuild shops, and at the somewhat reputable parts jobbers such as Napa and Carquest.

One time when the store that I get terminals from was out of stock they had some like yours, but with four bolts instead of two. I sanded them on the inside, sanded the threads of the bolts, smeared flux all over the sanded areas, bolted them to the cables, and soldered them. Then I ruined the heads of the bolts so nobody would try to loosen them.

Another option: Install a RV dual battery setup and/or get a battery tender. If you have a particularly harrowing commute you can hook it up to the battery tender all night to keep the batteries in top condition. Yuasa recommends batteries be topped off with an AC charger once a month in winter and every two weeks in summer whether a vehicle is driven or not to make sure they don't get sulfated.