battery connections

[tobyS]

I removed my 923's Hawkers and have installed two 1440 cca bus batteries. (Hawkers going to bench for deep recharging). I had to make new wood for under them and on the sides to keep the terminals out of the seat. But in the re-wire, I lost track of the three wires that connect to the larger battery wires. One was taped to the positive and one the negative and the other seemed to go to the center jumper (for 12v). I also disconnected the slave jumpers for now.

My question is with those three wires. When I look at the TM wiring diagram, I'm having a hard time following them out. Can anyone tell me what would operate from 12 volt on a 923, since one of them is connected to the series jumper or do I possibly have something wrong. It starts and runs fine but I do not appear to have low air lights and buzzer. But I'm not sure I ever did on this truck. Any help is appreciated. Toby

 

[Andyrv6av8r]

I believe the 12 volts is for Low speed on the heater blower motor.

 

[M35A2-AZ]

And the other little wires are 24v for the ABS if you have ABS on your truck.

 

[73m819]

Had WRONG info

 

[tobyS]

"Cold start Igniter" ??? Please explain as I thought the only assist for cold start was ether. This is a 923, not an 809, so may not be similarly equipped. But I'd like to know if I've missed it. Sure would like a 120v block water heater for winter. I hear they are cold blooded, some requiring heating of the incoming air.

 

[doghead]

Did you look at the schematic in the TM?

 

[tobyS]

Yes but I'm going to have to spend a lot more time there. I tried to print it out, but don't have a microscope to follow it. When I blow it up in the computer, it does not translate to a larger printed version. I need an 18 x 24 but haven't figured out how to get that yet. And I'd similarly like the air schematics. Any suggestions on getting large print versions?

 

[Csm Davis]

A good chance the 12v is for the cold start igniter, at least on the 809s with the 250, the heater uses a voltage drop resister to get low for the fan

Not on 939 series that I have ever seen

 

[quickfarms]

Yes but I'm going to have to spend a lot more time there. I tried to print it out, but don't have a microscope to follow it. When I blow it up in the computer, it does not translate to a larger printed version. I need an 18 x 24 but haven't figured out how to get that yet. And I'd similarly like the air schematics. Any suggestions on getting large print versions?

Are you printing it on a large format printer?

 

[TurboMustang370]

What's your method of bench charing the batteries? I need to charge mine and didn't want to ruin them. I topped them off with some distilled water and epson salt already to try de-sulfating them.

 

[tobyS]

TurboMustang, VERY, very long trickle charge (2a)...like five days each (don't be surprised that it reads 6-8 amps for several days). Then go back on the regular charger setting (6a) to top them off. Some people say to have a regular lead acid battery in parallel but mine seem to be going up. I did Optima's the same way, but these Hawkers are more stubborn and would not take charge while in the truck. Lowest was 8.4 volts, one 9 and two over 12...so not so bad. Bought two more 923's (to sell), so they will be ready for another truck after about only 24 days of charging. Charging time that I used to measure in hours is now days.

 

[tobyS]

No Quickfarms, I have a regular legal/letter size and could paste together... but can't get there with what I have. I would buy a full size copy if you can make one.

 

[RicheyOne]

I have just purchased a M923A2. It has the four battery setup and needed a jump to start. Once started, everything was great and I drove it 150 miles with no problems (the volt gage was in the green the whole trip) however when I shut it off the batteries appear to be weak to dead and would not turn over. I removed the four batteries and bought two heavy duty (950 CCA) batteries. I've attempted to wire these up and failed. I need a picture or diagram of how to wire these up correctly. Please help.

 

[tobyS]

RicheyOne, You must have them in "series" so they make 24 volt. If they are in parallel, they will make 12 volt. Series connection is where one batteries positive is connected with the other batteries negative by a jumper (usually a short lead) . Then you will measure 24 volt from the remaining two terminals (one on each battery), one positive and one negative. The frame is connected to the negative terminal and the other (positive) goes to the starter solenoid. All my trucks have a small lead that goes to the center jumper, which is then giving 12 volt (but I'm not sure what is working off 12 volt...andyrv6 says it's low speed heater blower motor). M35a2 says the other two small leads are for 24 v to the anti-lock brakes. You can't see them in my setup but you can barely see the center one.

Here is my two battery connection although they are larger batteries.

MAKE SURE YOUR BATTERY TERMINAL WILL NOT GET UP AGAINST THE SEAT BOTTOM. BAD THINGS HAPPEN.

 

[RicheyOne]

Thank you very much...Do you know which post the 12v goes to? I have hooked up as you said leaving the 12v lead loose and will not start. No power, no nothing. Would the 12v lead keep the truck from starting - no gages or nothing working. I greatly appreciate your help....I'm getting ready to hit you with a basic 101 question. The red wrapped wire is the positive right?

 

[RicheyOne]

Here is a photo of my set up..

 

[M35A2-AZ]

If you put the 12v on that pos post it would be 24v not 12v, That is were the ABS wiring goes and the heater 12v wire on the other pos post.

Yes Red is Positive.

 

[tobyS]

You have more than a battery issue if you have nothing with the battery cables connected as your drawing shows. You have cleaned all connection ends haven't you? Check to make sure the lead you think is going to the starter is not mixed up and connected to the negative. While red is usually positive and you have it connected to the positive terminal of the battery, follow it out all the way to the starter. Having them backward will give "nothing" I believe. Otherwise you are in series correctly from the looks of it (after changing the 12 v lead to what M35A2 has shown) and need to progress to meter readings or a solenoid jumper.

You probably need to spend some time studying in the Technical Manual or find a friend that has troubleshooting experience. Do you have a multi meter for testing voltage and resistance (or lack of)?

 

[RicheyOne]

I did not clean any connections. I will do that.. I did follow the positive wire back to the starter and it is connected to the starter solenoid. The thing that puzzles me is that its not doing any thing when I turn on the batteries and try to start. I will check the batteries voltage and keep plugging away. Thank you for you help. By the way, after following the positive wire to the starter, I stood up and forgot that I left the passenger door open and split my head open. Just got back from hospital... 3 stapes... The irony of this is that I have always preached (Be aware of your surroundings at all times) Guess I needed a reminder..

 

[doghead]

Staples, impressive! I've only dropped to my knees in pain and confusion from hitting my head on the bottom of the door.

Have you looked at the schematic under the seat(or battery cover)?