The 91 does start up every time, but very slowwww. The previous owner put in a new Interstate battery about a year ago but he put in a very underpowered and weak 750 CCA. The alternator, regulator and starter were replaced within the same time frame as well (have receipts, done by shop). When plugged in and the grids not engaged, it is slightly faster, but not much. I cleaned the battery terminals and checked the engine ground connections as well. So, I was going to head down to NAPA and buy a correct 1125 CCA battery for $171 but thought I would have them put their Midtronic charging and diagnostic equipment on the truck. They did and confirmed the battery is good (although not correct CCA for truck) and battery was putting out 13.1. It also said starter is good. Somehow the equipment determines starter status when starting truck. The Midtronic tester noted an issue exists in the charging circuit with an oscillation or pulsing pattern. The NAPA employee said that could be a bad diode in the alternator or could possibly be the regulator. I plan on getting a correct powered battery for the truck but something else might be going on and I need some suggestions for further trouble shooting. I could just replace the regulator with another new one for $15 and rule that out. I don't like parts replacing for guessing even though it is a cheap part. I could take the alternator out of the truck and have them test it individually at NAPA but would rather not unless it is the next logical thing to do. My thought about the oscillation or "pulsing" condition is that the battery was still putting out 13.1 which suggests the charging system is still fully doing its job? I am not an electrically savy individual and hope to get some next step options I can follow up with. Thanks in advance.

 

Interstate batteries behind Albertsons on 128 off I-5 lynnwood

Budget Batteries 196 & highway 99 1or2 blocks west.

Woops

I typed before reading all.

I.B. might test BUT the bats are way lower than NAPA you can get blems.I bought them for my boat 02 still strong, camper also still strong 40$ each

B.B. does test last one I bought there for the truck was 90 bucks that was 6yrs ago still strong

 

Check the voltage drops on both battery cables while cranking.

Sent from my NexusHD2 using Tapatalk

 

Thanks, I will call them both for pricing on a 1125 or better CCA battery. What CCA are you running in your truck?

 

I do have a multi meter laying around somewhere in the garage. I believe it is an older analog one. Are you thinking even though the battery tests out as "good" it might be bad or possibly a bad positive or negative ground cable?

Also, when you say test at both cables you mean meter terminal ground at chassis and meter terminal at positive cable while cranking, check drop. Then crank again with meter terminal ground at chassis and meter terminal end at negative battery cable, check drop? Thanks for the help and pardon my electrical skills

 

CCA in my truck how do I answer this. Beats me they work.

TRUCK 1
Ive been buying my bats from BB in tacoma 4ever. I pull in they ask what do I need I say you tell me. I pop the hood they tell me if I need a starter, alt, or reg. They sell me the right bat if I need one. They wont sell you the wrong size they have been around to long. In fact they have a contract with the city.
I dont know much about the lynnwood store. Ive only been the once and they put a new battery cable on I guess that was all it needed.

Truck 2

I just bought it 30days ago PO put a new NAPA bat in.. in 09

 

Minimum CCA for that rig is 1000. The battery holder will take a group 31, which is available up to 1200 or so. 1000 will do fine. 750 will crank slow if it's fresh. 1 year old and it's totally shot. There's just too much to do for such a wimpy battery to hold up.

BTW, when you crank a heavy load with insufficient battery, starter current goes up, not down, and starter wear and tear goes up with it. Multiply that by the extra time it has to crank, and you are decreasing starter life by a pretty high factor, probably 5 to 1 or more.

 

Not sure why anyone would put such an under powered 750 CCA battery in a truck like that either?? I just want to make sure I don't have another unknown electrical gremlin there also. Don't know what to make of, if anything, regarding that charging pulsation finding if the battery is getting fully charged
I hope Faith will get back to me soon regarding my question/clarification above.

 

To test each cable for voltage drop, you want to put the meter negative probe on the battery negative terminal and the meter positive probe on the engine end of the negative cable. Crank the engine, and while the load is going through the cable the voltmeter shouldn't read higher than .3 of a volt.

Now, hook the meter positive probe to the battery positive terminal and the meter negative probe to the starter end of the positive battery cable. Same thing, crank the engine and the voltmeter shouldn't read higher than .3v while the load is going through the cable. Anything over .3v is potentially excessive voltage drop across that cable and will contribute to your problem.

 

Ok, the test connection points make perfect sense now. Thanks for that! But I am missing something...Prior to cranking I should see the batteries at rest 12 or 13 volts on the meter at the negative or positive cable test connection points above, correct? On crank, I should see no less than .3 of a volt drop from that at rest battery voltage? If I do, cable run is bad.

Also, as it turns out I have a digital multi meter but the positive and negative terminal wires are approx 2 feet each for a total of 4 feet length. Might have enough length but it will be close. They are not alligator clip type connectors so I will either have to tape them at the connections or do some good arm stretching and balancing to hold while another cranks.

 

Ok, found this on voltage drop testing and I fully understand. Will be doing this in the next couple days. Thanks all.

http://www.aa1car.com/library/voltage_drop_testing.htm

 

I'm gonna say the starter needs brushes.

 

Are you sure the grid heaters weren't cycling? That could fool the average NAPA "tech", or his "idiot proof" tester.

 

I have a 750 CCA battery in my truck now and it doesnt even turn over 1 time and starts I would be looking at your cables or starter drag you might not be getting the power down to the starter?

 

No, the truck had been driven a while and was good and hot. Definately were not cycling.