Need help swapping a Chrysler 85hp with a Force 85hp

[jombee]

Hi,

I'm swapping out a 1979 Chrysler 85 HP with a 1986 Force 85HP and am having some problems.

I'm using all the same cables/wires/connections that were on my 1979 OB (my boat is a 1979 Chrysler Bassrunner)

Everything works fine (throttle, hydraulic trim/tilt, etc.) except the 2 issues below

1. When I connect all 8 wires to the terminal, if the blue wire "magneto" is connected, the circuit breaker "pops" when the key is turned. If I remove the blue wire, the engine starts and runs fine, but cannot be shut off by turning off the key (or even removing the key). The same blue wire is connected on my 1979 Chrysler OB, and there is a blue wire on the other side going to the engine. There is not a blue wire on other side of the terminal going to the engine on the 1986 Force (see pictures).

2. The tachometer runs really high (like 8,000 RPMS) when the engine is clearly just idling.

Any help would be greatly appreciated!

 

[The Force power]

I'm not a 100% sure, but make sure that both Magneto wires go to the Rectifier & from one of the magneto-wire to the Tach.

I attached a link from Bayliner that had the Wiring set-up for the Force-motors, you may have to check every single wire from your boat's controls to match them up onto the Force motor

https://bayliner.com/wp-content/uploads/2016/06/1990-Capri-Trophy.pdf

 

[jombee]

Thanks, but there is no blue wire on the "other side" of the panel going anywhere on the Force OB (see attached picture above). There is a blue wire (actually 2 of them) on the other side of of the Chrysler OB (see picture below)

 

[The Force power]

I'll look for the Force schematic

 

[jombee]

Thanks! I believe the diagram shows nothing coming out of blue on the panel, but it does show a wire coming in from blue from the ignition. When I connect the blue from the ignition (using the harness/ignition from my Chrysler), it pops the breaker. I believe I have type 3 ignition on the Force, but I am not sure. My 85HP Chrysler had wires coming out of blue, but it also had a distributor, which my 85hp Force does not.

 

[jerryjerry05]

The old key switch and some connections won't work on the newer motor.
This is a few pics that might help??

 

[jombee]

Hi Jerry

Thanks, but I'm confused by the pics

I actually do have the ignition key and wiring harness for the new Force motor. I was hoping I could just use the existing Chrysler stuff to make the change over easier. Should I just remove the old key ignition/wires and use the ones I got with the Force motor?

 

[The Force power]

I would use the Force wiring if you don't, you'll have to;
Identify every single wire from the old Chrysler-harness (it's function) and match-up with the Force-wiring's function.

This maybe more work then swapping-out the harness, due to you may have to convert/jump certain wires and ultimate designing your own harness. what makes things more complicated when working with a schematic.

 

[jombee]

Thank you very much!

I will try swapping out the harness

 

[The Force power]

Help full hint

BEFORE you do the swap; check the continuity on every wire from that Force harness that going in the boat, that way you know it's good and what wire needs to be repaired.

it will save you a lot of time afterwards second guessing your work/hook up

have fun while your doing the work

 

[jombee]

Thanks!

I could also just hook up everything to the motor and test before running the wires, correct?

 

[Nordin]

Your Chrysler 85Hp has battery CD ignition feed by the battery and you shut off the engine by shut off 12VDC from battery to the CD box. Blue wires connected to I termial at keyswitch.
One blue goes to the CD box and distributer(electronic dist) from the terminal board by the keyswitch.
Blue wires feed by red wire at B terminal at keyswitch when key in ON and start position.
M terminals not in use.

Your 85Hp Force have self energized magneto CD system and you shut off the engine by grounding out the CD boxes.
M terminals are short circuit when OFF, one white wire at keyswitch at M terminal and blue wire at the other M terminal.
At terminal board blue wire grounds out with a jumper to ground and white are connected to black/yellow wires which goes to CD boxes.

Check out the wire diagram Force 125Hp (Prestolite) at Mastertech Marine site.
Similar wiring as for your 3 cyl. 85Hp Force just one more cylinder fpr the 125Hp.

 

[jerryjerry05]

I didn't know you had the harness?????
The easiest is use the newer one.

 

[The Force power]

Like Jerry said; use the Force harness, but check the wiring before hook-up; that way you know if there's any bad wires in the harness

 

[jombee]

Thanks everyone! I will try using the Force harness, it seems like my best option. I really appreciate everyone's help!

 

[Nordin]

Why change harness when you have one already in the boat???
You only have to change some of the connection for some of the wires.
One or maybe two of the wires.

Check out the wire diagram at Mastertech Marine.

 

[kbh121956]

You do not need to change out the wiring harness as Chrysler and Force uses the same harness. The 85Hp Chrysler's have a battery CD ignition system from Motorola with a belt driven distributor. It uses the battery to charge the CD box.

The Force 85Hp has magneto CDI ignition from Prestolite that use magnets in the flywheel to charge the CDI box.

Here is how to hook up wires.
The different is in the stop circuit and you have to rewire your keyswitch.

Force 85Hp

Terminal strip at engine Wire color Keyswitch Function

Yellow - Yellow S terminal Start
Green - Green C terminal Choke
Red - Red B terminal Power
White - White M terminal (one of them) Stop
Blue (jumper to black ground) Blue M terminal (the other) Stop
Purple - Purple Tacho
Orange - Orange Overheat
Black - Black Ground

Terminal I at keyswitch is only to use for auxiliaries, to power it when key in ignition position. Note: The Force outboard uses a 20 pole tach. The Chrysler tach will not work if your boat is equipped with one.

 

[jerryjerry05]

They don't use the same harness.
The Chrysler doesn't have all the wires the Force does.
No T@T
The color code is different too.
In the early 80's marine manufacturers standardized the color code.

 

[jombee]

Ok. so now I am confused.

I will be working on my boat this coming weekend and would like to do whatever is easiest (considering my limited experience/skill).

Currently, my 1979 Chrysler harness is connected to the new 1986 Force OB.

The Force is mounted on the boat, steering, throttle, trim & tilt all work fine.

The Force starts fine but doesn't shut off and the tach runs way too high. The T@T (trim & tilt?), works fine, but has no wires going to it from the harness.

I have a harness for the Force and I also have a tach from the Force (both loose)

I'm just looking for the easiest fix here, and I really appreciate any additional advice

 

[kbh121956]

Jerry, I have removed a 75HP and a 85HP Chrysler outboards mid 70's. Both had T@T. I installed the more modern Force using the Chrysler Harness that was in the boats. The Chrysler Tach wouldn't work. All that was needed was to change the wiring at the key switch. I do not have the experience that you have nor the knowledge that you have. Just stating what I have done for a couple of boating friends. It could be that the harness in them were changed? I don't know. I would check how many wires and the color code on the boats harness before changing it out.