Weak battery and no start

[MrBouncer]

Need some thoughts here. If you have a loose battery terminal and when it starts it sounds like a weak battery. Had this problem about a week. Got up this morning to start it and it just clicks, sounds like a dead battery. Switched the batteries and still the same. I am thinking poor charging all week combined with having to run lights to and from work that it has had enough. I just want to make sure with the relay system in the CUCV's that I have created another problem. Thanks

 

[ralbelt]

According to the TM when diagnosing electricl problems always make sure the batteries are fully charged.

 

[319]

I am thinking poor charging all week combined with having to run lights to and from work that it has had enough. I just want to make sure with the relay system in the CUCV's that I have created another problem. Thanks

Fully charge the batteries, then clean and tighten all of your battery connections and report back.

 

[bubba_got_you]

 

[jimmy-90]

One thing you can check really quickly and easily are your fuses. I had the fuse to my gen 2 light blow out and the batterys got weaker and weaker until the truck wouldn't start.

 

[MrBouncer]

OK found problem main starter cable got loose and burnt the connector through. That problem is fixed. Now horn wont shut off, no headlights, all other lights extra bright, charging in yellow, gen 1 light stays on, gen 2 light doesnt come on. Batteries measure 12.4 each and the same at each alt and 25 volts on the entire circuit. Do yall think relays or alts.

 

[ssgtcampbell77]

The first rule of owing a CUCV, "If its rubber replace it, if its electrical clean it".

 

[MrBouncer]

mama if you aint got anything useful to say dont say anything

 

[ssgtcampbell77]

Hahahaha.... seriously, I had the same issue. Pull all your connections and clean them (one at a time so as not to cross wire anything). If that doesnt work, check your relay (under dash). When I cleaned all my connections, problem solved. Then I cooked my relay (or starter solenoid....not sure just yet). I was shocked to see just how loose and nasty all my connections were.

 

[Warthog]

The horn issue is either A.) a stuck horn button or B.) the Diode on the back side of the horn relay near the fuse box has gone bad.

You can just remove the diode or replace it.

 

[MrBouncer]

I have got 24 volts moving to everything in the system. I havent checked all things with a voltmeter but the fan is running super hard and all bulbs are exrta bright. I am thinking voltage regulater. I am going to take to alts off and have the tested. None of this happened until I repaired the starter and reconnected the batteries. The horn was raising HADES. Spent half the day thinking it was solely with the horn.

 

[lilymonster]

One thing you can check really quickly and easily are your fuses. I had the fuse to my gen 2 light blow out and the batterys got weaker and weaker until the truck wouldn't start.

Jimmy, where are the fuses for the gen lights?

 

[jimmy-90]

The fuse that is hooked to the gen 2 light is on the left hand side of the fuse box. It is a 20A fuse. You might as well check all of them while you are down there though I don't think a blown fuse is whats causing all the rest of your problems.

 

[MrBouncer]

I have checked all the fuses, tested relays, read TMs. What keeps the system from becoming entirely 24volts? Is it a single item or a series of items?

 

[Red_506]

Did you check all the connections on the firewall?

 

[MrBouncer]

yes

 

[mistaken1]

I have checked all the fuses, tested relays, read TMs. What keeps the system from becoming entirely 24volts? Is it a single item or a series of items?

The negative side of the back battery is connected to the 12V terminal block on the firewall by the glow plug relay. That is where the truck gets 12V for everything.

The positive of the back battery is connected to the large terminal block on the firewall behind that battery. That is where the starter and glow plug relay (via the resistor on the firewall) get 24V.

 

[MrBouncer]

To recap, thought it was weak battery turned out to be a loose wire to the starter (main red) fixed that now 24 volts running to every thing (based solely on bulbs blowing and brightness, fan speed, horn wont stop) so Ithought alternater or voltage regulater. Took to be tested which led to both being rebuilt. Problem still continues. Starter relays? I cant think of anything else.

 

[mistaken1]

To recap, thought it was weak battery turned out to be a loose wire to the starter (main red) fixed that now 24 volts running to every thing (based solely on bulbs blowing and brightness, fan speed, horn wont stop) so Ithought alternater or voltage regulater. Took to be tested which led to both being rebuilt. Problem still continues. Starter relays? I cant think of anything else.

You cannot troubleshoot electrical problems without an electrical meter.

Go to wally world and buy a volt/ohm meter and use it to verify that you have 24V where you think you have it (rather than assuming that based solely on bulbs blowing and brightness, fan speed, horn wont stop).

If you have 24V where you should not that is a serious issue that needs to be fixed, it may be too late for many 12V components if they have been subjected to 24V for any length of time.

There is a diamond shaped block on the firewall by the glow plug relay (drivers side). What voltage does your newly purchased meter indicate for voltage at this point?

Do you know if your batteries and junction blocks are all wired correctly?

If not download the TMs and look at the wiring diagrams to see how they should be wired into the rest of the truck.

The manuals can be found here:
CUCV Manuals Courtesy of Jatonka

 

[MrBouncer]

All is wired correctly got voltmeter but how long would you let something draw to much current that you can plainly see is drawing to much just to put a number on it. What could go wrong when you disconect batteries, put on new main starter wire and reconnect. So how is a loose starter wire related to overvoltage?