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  #1  
Old June 13th, 2018, 12:17
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Battery Voltage - Renix

Can one of you with a Renix and a full gauge cluster tell me what your dash voltmeter reads when the key is in RUN but you have not started the engine yet.

I'm having an intermittent sluggish start. I've cleaned both ends of my battery cables. Will get my starter and battery tested soon.

I noted that my dash voltmeter shows about 11v in Run but not started and almost 14 engine running with no accessories/lights on. I just never noticed it before. I measured at the battery and get 12.6 key off, 12.26 key on but not running, and over 14 running.

Thanks!
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Old June 13th, 2018, 15:37
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Re: Battery Voltage - Renix

What is the battery voltage (at the battery) during crank? Below 8.5-to 9V is a bad battery. 9-10V is weak. 10V up is ok. Bear in mind there is some fudge factor for ambient and engine temp. The dash guage isnt really the most accurate when the truck gets this old.
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Old June 13th, 2018, 16:03
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Re: Battery Voltage - Renix

Thanks, during cranking I get about 10.5V While doing this and the earlier measurements, I did not experience the "sluggishness".

I'll try "jumping it" at the starter relay, key off and see how it goes.
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Old June 13th, 2018, 18:10
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Re: Battery Voltage - Renix

Quote:
Originally Posted by Saudade View Post
Thanks, during cranking I get about 10.5V While doing this and the earlier measurements, I did not experience the "sluggishness".
My 90' would struggle with this voltage. I just replaced my battery with an AGM and bought a "smart" charger. This pairing is the best combination this jeep has had in over 25 years. 12-13v during turn-over and over 14v during run. Response is perky. I have one of these plugged into the cigarette lighter socket to monitor;

https://www.ebay.ca/itm/12V-24V-LED-...AOSwDkVaaue v

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Old June 14th, 2018, 10:14
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Re: Battery Voltage - Renix

So after a few more sluggish cranks, I just took it to my local Auto Center to test the battery. Tested bad. My 4th year on a 3 year battery. Case Closed.
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Old June 14th, 2018, 14:50
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Re: Battery Voltage - Renix

Pehaps my math was bad then. Glad it was figured out.
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Old June 14th, 2018, 15:46
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Re: Battery Voltage - Renix

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Pehaps my math was bad then. Glad it was figured out.
Not so fast there. After a few more errands I had a sluggish start AGAIN (several)!! I saw the print out from the battery tester. It was not able to complete the recharge so it said "Replace Battery". It almost didn't start when leaving the parts store to get a replacement starter.

So I put in the new starter in and cranking it screams (in a good way). My old starter has a lifetime warranty so I should get a refund when I return the core. Good thing the starter is easy to replace.

So what the chance of both battery and starter being "bad"!!
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Old June 15th, 2018, 12:25
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Re: Battery Voltage - Renix

It is quite possible. Low cranking voltage can cause excess heat in a starter and cause failure.
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Old June 15th, 2018, 17:09
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Re: Battery Voltage - Renix

... or more likely a "going south" alternator not doing its job of charging the battery and the battery gradually being killed due to insufficient recharge.
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Old June 16th, 2018, 09:01
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Re: Battery Voltage - Renix

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It is quite possible. Low cranking voltage can cause excess heat in a starter and cause failure.
I agree, quite possible. The "cranking speed" seems much higher than it's been in a while. But, I've also cleaned all contacts including starter mounting surfaces and the engine grounds.

Thanks for your input!!
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Old June 16th, 2018, 09:04
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Re: Battery Voltage - Renix

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... or more likely a "going south" alternator not doing its job of charging the battery and the battery gradually being killed due to insufficient recharge.
I suspected that early on. Charging seems to be OK. I get ~14.5V engine running.

Still, I'll keep checking to be sure.

Thanks for your input!!
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