| Author |
Message |
Duane Kaler (Duane)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 07, 2006 - 6:16 pm: | |
I am looking at installing an automated transmission in my bus and I know I am am going to stay with 24v for the coach. What is the best way to supply the transmission electronics with the 12v thay require?
Thanks, Duane |
Ed Jewett (Kristinsgrandpa)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 07, 2006 - 7:22 pm: | |
My coach came from the factory with a Vanner 50 AMP 12V power supply for the DDEC-II and the ATEC.
The 50 AMP wasn't necessary but all the lights are 12 V. The only thing 24 V on it is the starter.
Ed. |
JR
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 08, 2006 - 9:27 pm: | |
Center tap the 12V post between the batteries. That's where DDEC, and ATEC, units pick up their 12V source. Generally a Vanner doesn't "supply" 12V, it just keeps the two batteries equal. Most bus headlite systems operate on 24V...even though the headlights are 12V. They are wired in series, and use 12V only should a fault occur...such as a bulb burning out, or whatever loss of power to a headlight. A complicated bit of wiring and diodes supply the good headlight instantly.
Are you planning on mating an ATEC type transmission onto an MUI (you didn't say, so I'll assume such and prattle on)? That's going to require a good bit of work, even though there are stand-alone ATEC ECMs available. If this is what your doing, have you considered using an HT740 Allison Automatic? It will work with any MUI, or originally manual trans DDEC system. If your coach is a DDEC, the 12V is already piped to the rear junction box for the DDEC ignition relay. If your trying to avoid the shift cable, use an air shifter...easier to run than the ATEC wiring harness. ATEC HT748s are expensive(relatively). And most ATEC takeouts will have ECMs that are programmed to communicate with a DDEC system. You'll have to find an ECM, or have DD reprogram your ECM to function as best as it can without the com link.
My guess is that the up and downshift points will require a lot of button pushing. There is not throttle linkage on ATECs and it will have no idea when to shift other than VSS input. It'll go into 4th lockup at 35 MPH, or wherever it's programmed.
I reckon this is all thought though. I'd be interested in what sort of bus and engine you have.
Please pardon this post if your installing an electronic/manual Roadranger or ZF sort of thingy...that will be REAL expensive. In any event, the part about picking up 12VDC is applicable for any trans ECM. Post some pix of what you're doing. |
Duane Kaler (Duane)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 09, 2006 - 1:18 am: | |
Thanks for the info JR. My coach is an MC7 with an 871 and a manual 4 speed. I dont like the 4 speed so I am considering installing a 10spd auto select. I am new to the bus thing and I have seen reference to the battery center tap but did not know if that was the best place to draw power for the ECMs. As for pictures I will post an update with pix once I get to that part.
Thanks, Duane |
Rainbow Coach Conversions
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, June 11, 2006 - 12:21 am: | |
Use the Vanner for your 12volts. It will save you from being stuck with dead batteries caused by center tapping the 24v. |
Duane Kaler (Duane)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 12, 2006 - 4:49 pm: | |
Could someone tell me more about this "Vanner" and where it might be located on an MC7 if it even has one?
Thanks, Duane |
Rainbow Coach Conversions
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 13, 2006 - 1:19 am: | |
I first started using Vanner Battery Equalizers in the late 1980s. The buses started using them for the 12 volt TVs and VCRs. You won't have one on a MC7 unless added much later.
I charge the house batteries at 24v and use the Vanner to get my 12v. This enables you to have 24v for the Invertor and running roof air while driving. |
Rainbow Coach Conversions
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 13, 2006 - 12:25 pm: | |
Duane
You may be asking what the Vanner does. Putting 2 12 volt batteries in series gives 24v. Center tap gives 12v off the grounded battery. That draws down the grounded battery. The system is now out of balance, like having a bad cell in a battery. They will not charge proper. The Vanner connects to the 24v, 12V (center tap) and ground. When 12v is drawn from the center tap the Vanner is able to draw this 12v from either battery keeping them in balance. This is the simple explaination.Never had a problem with one. |