Rough start, batteries or starter?

[divemedic]

This morning I had a rough start (1 hiccup). Radio memory was intact. During lunch I had the same. After work the truck had a significantly tougher time turning over. 3 or 4 hiccups before turning on. Also the radio lost its memory. The factory volt gauge was/is in the green (I don't have a multimeter currently but I have no reason to believe the gauge isn't functioning).

I mention my radio because it's wired into the first battery for 12v power. Everything is on a kill switch sans the memory power line which has a parasitic constant draw. That said, historically the truck has sat for upwards of a month without starting and never had an issue with the memory draw. The setup has functioned fine since install. I did intend on getting a battery conditioning controller once I start adding more accessories, I may need to bump that up on my to-do list.

For now I've disconnected the radio from all power sources and I'm currently letting the truck ideal at 1500rpm to recharge the batteries (just in case I'm experiencing mismatching charges on my batteries and/or my gauge is malfunctioning).

Im worried it may be my starter going out on me, but the memory on the radio losing power leads me to believe that's not the case. Other ideas maybe a relay or fuse that may have been toasted by the shippers of my vehicle causing my batteries not to get a charge, possible? Any ideas on what/how to trouble shoot. I'm not well versed in the electrical side of things. Thank you in advance.

 

[divemedic]

So I let it sit for 2 hours with all known electrical components off and the radio disconnected. The dash gauge read on the bottom end of green with only ignition on. 1 big hiccup to start and the gauge stayed low at idol. I cranked the throttle control knob up to 2k rpm and the needle rose to 3/4 green on the volt gauge. I'm thinking I have a blown relay somewhere causing a parasitic draw or perhaps my alternator to going/gone. Side note: The belt seemed a bit loose, I'm not sure what the actual tolerance should be on the tensioner pulley but I may try tightening it up a bit in the am. Advise direction would be much appreciated. Thank you.

 

[Eco 45]

I would check your batteries first. Let it sit overnight and put a meter on each battery---they should be pretty much matched in voltage. When you run a 12V item on only one of the batteries in a 24V system is can cause them to charge differently and one ends up dying sooner than the other. It is always best to use a 24V to 12V converter. Caterpillar actually makes a good one. All it takes is one of the two batteries to be under 12V and these trucks can be hard to start. If the batteries check out, then move onto the charging system--again best to use an actual meter to see what volts the system is charging.

 

[divemedic]

I'll look at buying one. Same issue this morning. Normally I wouldn't hesitate to think your correct about the mismatching charges on the batteries. But, I ran the set up for about a year with no issues. The current batteries are brand new, less then a month old. That said, it's getting cold in Ohio, but not any worse then Okinawa in the dead of winter. Could the weather be a catalyst?

Given they are new batteries I'll exchange them for new units and see what happens. More input for other causes would be appreciated.

 

[Cavalier2000]

You have any luck fool?

 

[divemedic]

Quick update:
I broke down and bought another voltmeter. This morning I took readings after the truck sat overnight, and after two failed start attempts. Battery 1 was sitting at 9.5V and battery 2 was sitting at 12.6V. Combined they pushed 23.3V (the math doesn’t make sense to me, but that’s the readings I was getting). Today my plan is to trade in for new batteries as the current ones are still under warrantee. Then I’d like to get the alternator tested. Perhaps this may narrow down the cause. At a minimum it will remove the radio as being the culprit. I’ve been advised by some smart guys that it may likely be the alternator regulator. So I may need to start sourcing that part. I’ve also been advised to start chasing grounds. Unfortunately I don’t have the space, nor the tools to start digging around until I move into my house.

 

[scalpel1]

I am in a very similar situation currently. I have stripped the alternator. The rotor's resistance tests very low. I will take it in to test at auto electrician. Then the next step is the voltage regulator.

 

[jblueridge]

I don't know your situation but an auto electric shop that specializes in starters and such could test the alternator for a moderate fee, or even free. I had to drive about 100 miles to get to one for my 24v gizmos.

 

[cruiserdan]

The 9.5 volt battery is the problem. with such a divergent voltage it will be a challenge for the 24v alternator to charge them back up correctly. My guess is the center tap may have pulled that battery down over time and this is a cumulative result. Center taps are never a good solution.

 

[divemedic]

Agree with the above advice. But wait there is more!!!!

When I pulled the batteries to swap them out I discovered the bridge wire had arc welded to the terminal of second battery (not the terminal which the 12v center tap). This leads me to believe a voltage regulator blew. Any thoughts?

 

[divemedic]

I am in a very similar situation currently. I have stripped the alternator. The rotor's resistance tests very low. I will take it in to test at auto electrician. Then the next step is the voltage regulator.

I found this little gem searching for solutions. May be of some help to you.

24V Alternator Upgrade

 

[divemedic]

Update: Got new batteries and replaced the bridge wire. When the truck is running I'm getting 28v total with 14v at each battery. The power is even but high. This leads me to believe, more so, it's the voltage regulator for the alternator. I'm not an electrical expert by any stretch so I'd love to hear thoughts/advice?

 

[scalpel1]

Thanks Divemedic. Interesting read.

 

[kbushnz]

That voltage when running sounds about right. For a normal 12v system you want to see 14v plus from the alternator.
Those photos of the battery terminal arching look typical of a dirty clamp. Need to clean those battery leads so you get a good contact between the post and clamp. They may look clean but may have a layer of oxide on them.

 

[divemedic]

Thank you. for the input I too am hoping it was a simple cable problem.

 

[cruiserdan]

I'd hope to see 28 volts with the engine running and a load. Do remember the gauge is graduated to 32 volts.

 

[Eric Winkworth]

That doesn't sound high to me, get someone to rev the engine while you check the voltage. If it increases and decreases with engine speed your regulator maybe suspect. otherwise look elsewhere.

These trucks aren't easy on regular s***ty batteries. If you wanna tap off the 12V side you shorten the life even more. I have found after years of getting 3 or 4 years out of s***ty motomaster batteries, getting free replacements started annoying me. I made new battery trays and stuffed group 31's in my truck, I was happy with the result, they're heavy industial truck batteries. They're pretty cheap for what they are and they are tough as nails. It's way more battery then you need, so even when they get old and beat up they still work deadly! A good Solar converter in my setup helped a great deal as well, but nothing impressed me more then my group 31's!