Alternator Upgrade

[CGCWO]

Anyone using this DB alternator on a RENIX 4.0? Application list says it fits.

https://www.dbelectrical.com/products/alternator-high-output-160-amp-4-0-jeep-cherokee-87-88-89-90-wagoneer.html

Now that I have the REMII and full gauge cluster I noticed today that I am only seeing 10.5-10.9volts on the readings. Checked the battery readings with a bolt meter it shows 11.7-11.9volts. Also pulled the positive cable and truck dies. So thinking it’s time for a new alternator?

[omega_rugal]

now that we are talking about alternator, does anyone have the brand and model of the one used in 88 comanches? i´m trying to find parts to rebuild mine

[scaleless]

I believe the Renix alternator is simply a Delco CS130 alternator and rebuild parts from any CS130 alternator should work. 

[cruiser54]

19 hours ago, CGCWO said:

Anyone using this DB alternator on a RENIX 4.0? Application list says it fits.

https://www.dbelectrical.com/products/alternator-high-output-160-amp-4-0-jeep-cherokee-87-88-89-90-wagoneer.html

Now that I have the REMII and full gauge cluster I noticed today that I am only seeing 10.5-10.9volts on the readings. Checked the battery readings with a bolt meter it shows 11.7-11.9volts. Also pulled the positive cable and truck dies. So thinking it’s time for a new alternator?

 

Have you upgraded your cables? 

 

 

[CGCWO]

1 hour ago, cruiser54 said:

 

Have you upgraded your cables? 

 

 

Yes

[CGCWO]

Positive it’s a bad alternator, the more I run the truck the lower the voltage output is. When I stopped messing with it yesterday it was down to 9.7 on REMII and close to that on the cluster gauge.

[Ωhm]

I always thought cluster swap had no affect on charging until I read this thread. Now I don't know what to say, but something is going on here. Diode???

 

 

[cruiser54]

Never heard of a cluster swap causing charging issues.

[Greentoy]

On 4/4/2021 at 8:20 PM, cruiser54 said:

Never heard of a cluster swap causing charging issues.

I hadn’t either, but as soon as I swapped the full Gage cluster in place of the dummy lights, my alternator quit charging. I figured it was a bad alternator since it took a few days to run out of juice and die. Replaced alternator and still no charging. The cluster I picked up was on a YJ with v6 I believe. The alternator on both the 4.0 and 2.5 both need an exciter wire circuit in order to start charging. That is handled by the light in the dummy cluster and somehow must be handled by a diode built into the gauge cluster. I suppose it is possible that the v6 models use a different alternator that did not require an exciter wire. In that case maybe the cluster does not have it or my cluster diode was burned out? It was easier for me to add a simple one wire exciter wire right under the hood rather than disassemble the cluster. 

[CGCWO]

5 hours ago, Greentoy said:

I hadn’t either, but as soon as I swapped the full Gage cluster in place of the dummy lights, my alternator quit charging. I figured it was a bad alternator since it took a few days to run out of juice and die. Replaced alternator and still no charging. The cluster I picked up was on a YJ with v6 I believe. The alternator on both the 4.0 and 2.5 both need an exciter wire circuit in order to start charging. That is handled by the light in the dummy cluster and somehow must be handled by a diode built into the gauge cluster. I suppose it is possible that the v6 models use a different alternator that did not require an exciter wire. In that case maybe the cluster does not have it or my cluster diode was burned out? It was easier for me to add a simple one wire exciter wire right under the hood rather than disassemble the cluster. 

I am having the same problem with my cluster swap in the 1987 4.0. I will be installing a new higher amp alternator since I’ll be adding a winch in the future. Going to give @Greentoys fix a try if the new alt doesn’t charge.