Maxim-Seca Computer the same?

Was out riding today and stopped by the local bike junkyard. Happened to notice a 81-82 Maxim 750 with a complete gage cluster. Since the computer on my Seca is brain dead and the guy was willing to part with the complete cluster for what I had in my wallet ($13.00) I though I would take a chance on it.

I have checked on BikeBandit to see if the part numbers on the CMS were the same for the Maxim & Seca but they do not show a number for the Maxim model. My question is does anyone know if the computer monitoring system is the same for both bikes or do I have a $13.00 paperweight?

 

My understanding is that there is no computer on the maxims, at least on the 550s. The gauge cluster takes several input signals through the wiring harness (low oil pressure, neutral, turn, bright light) and has an input from the engine for rpms, and another from the transmission for road speed. This should make swapping the two easier, as you will just have to mate the wiring harnesses. Find a copy of the two wiring diagrams and it shouldnt be too difficult.

 

Part numbers are different. Like cide1 said, get a wiring diagram for both and that will tell you how you can hook it up.

 

Where did you find the part number on the Maxim computer?

I am not looking to swap the entire cluster I only want to remove the computer from the Maxim cluster and put it in my Seca cluster.

 

Seca Rob, you are in luck, the Max cluster is a drop in with a minor mod.
I'm running a 82 750 Max (there were no 81 750 Maxs) computer on my 750 Seca. It requires the addition of a diode (not present on the Seca harness). It is located in between the Light Blue wire from the Neutral switch and the Blue/Yellow wire off of the Side Stand switch. The cathode (the side with the line on it) must be toward the neutral switch. I've not made the mod yet or I would tell you the part number for the correct diode (I'm going to try an FR606 for starters, rated at 6 amps). Otherwise your neutral light will remain lit everytime you pull in the clutch regardless of being in neutral or not.
Good score at $13.00, I would like your unused parts if you are done with it (I scavenge parts and so on to fix other units). I happen to like the cluster style of the Maxim anyway.

 

Robert thanks for the feedback

I can confirm that it "DID" work. Today I went ahead and just thought I would check so I took the headlight off, removed the 2 plugs going to the existing unit layed the Maxim cluster on the front fender plugged it up turned on they key and "YAHOO" it seemed to work. I let it cycle thru and it reported that my headlight, fuel gage and sidestand we faulting. I shut if off and called the wife to show her how it worked. Turned the key on and once again it cycled thru giving the same errors.

Put the bike back together and went for a ride. Came home and removed the computer from the Maxim cluster. Removed the Seca cluster swapped out the computer and put it back together. Turned they key and "NOTHING". Double checked all my connections tried again and nothing....No warning light - no LCD cycle :cry:

Anyone have any ideas? Do I have a short somewhere that is killing the computer?

 

I had a similar problem on start-up of my newly obtained and gone-over Seca. Turned out to be a swapped set of the 3 pin connectors in the headlight bucket. Double check your connections by wire color code.
I forgot one point. The Maxim cluster needs a ground to be in the middle of the 9 pin connector. Get a ground routed through that position (swipe a lead off of a scrap harness or shoot me your address via PM and I'll send you a pig-tail). There is a ground you can use located in the 6 pin connector (the Black wire). If you have the Haynes manual, compare the schematic of the 750J to your 750RJ. You will see the ground point.
Because of these mods, I don't think you are going to get the computer to swap over easily. You could have a short but you said in your report of running the Max cluster that it did work so I'm not thinking it is the case.
If you want a Seca computer, I have one and would willingly fix yours if you want to ship me your cluster (provided you would part with your new Max cluster of course). I'd fix it and test it on my working 82 750 Seca and ship it back to you. This would eliminate the question of whether or not the Seca cluster is working.

 

Robert I did notice the missing center pin in the 9 pin connector. I really do think I fried this Maxim cluster because it no longer works.

I might take you up on the offer if I cant get this one working

Thanks

 

Yeah, I wish I had paid attention in that electronics class.

Capacitor/resistors/copperwire/aliens.....

 

Doh! Now what did I do?

I temporarily gave up on this and decided to put everything back together as she was.

Now in addition to a brain dead CMS whenever I let the clutch out with the bike in gear the neutral light will flash on and off once.
With the engine off and the bike in gear I can hear a click from one of the relays when I let out the clutch and also hear a clicking sound from another relay when I raise and lower the side stand. The light flashes when I do either of the above.

Perhaps on a related note. My tach seems to bounce all over now...This problem is also new....

Any ideas?

New thread perhaps?

 

OK, now I am really befuddled.... I hooked the Maxim cluster back up to see if I had the clicky/flash problem I still do but here is where I loose my mind. The LCD & Warning light on the Maxim cluster work once again..... However when I start the bike the lcd & warning light go out.....Crap I am confused

 

1982 750 & 650 Are the same ( computer)

Seca Part # 5G2-82305-10-00
Maxim Part #5G2-82305-10-00

But the 1981 maxim has a different Part # 4H7-82305-10-00

Looks to be the same part number for the 750/650 seca and the 750 maxim & the 650 maxim

Hope this helps you