1988 Marathon Issues

[thekidd76]

So based on what you said JohnnieB, I should first clean up all connections..paying special attention to connections to and from the controller, F/R switch and solenoid. If that doesn't work, replace those cables, then replace the solenoid and then the F/R switch progressively if nothing changes?

Based on what you see do I have a faulty controller or should that not be a concern at this point?

[JohnnieB]

Originally Posted by thekidd76

Just over 38.2 from the bank at rest

36.5 going up hill from the bank
33.2 going up hill from the controller.

And the cables changed here just the ones connecting the batteries. Not from bank to controller or any other electronics.

Originally Posted by thekidd76

So based on what you said JohnnieB, I should first clean up all connections..paying special attention to connections to and from the controller, F/R switch and solenoid. If that doesn't work, replace those cables, then replace the solenoid and then the F/R switch progressively if nothing changes?

Based on what you see do I have a faulty controller or should that not be a concern at this point?

Battery pack is dropping 1.7V under load. That is normal.
Dropping 3.3V between battery pack and controller output. Not good, but not terribly bad either.

Measure between controller's B- and B+ terminals going up same hill.
If it measures the same as what you get between M- and B+, than the controller is wide open and is good.

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All of the thick cables are in series, so they all carry the same number of amps to/through the motor and if any of them are getting hot (more than 10°F above ambient), they need to be replaced. The same is true of the sonlenoid contacts and the F/R switches four sets of contacts. The motor's brushes are also in series with the cables.

In a nutshell, there are 6 batteries, 13 cables, 26 cable connections, 5 pairs of contacts, 2 pairs of brushes, 2 pairs of stator windings and the armature connected in series and any one (or more) of those 60 odd items having excessive resistance can slow the cart more than usual on hills.

FWIW: In perfect condition, Marathons are notoriously slow on hills.

[camaroluvz28]

JohnnieB is the best when it comes to a proper diagnosis for sure...when you upgrade your controller be sure to upgrade your wires as well ;)...if that turns out to be the case...

[thekidd76]

Thanks guys. I’ll test the other controller contacts tomorrow.

[thekidd76]

After too much time away due to life, I'm back on this cart. Still having the same issues. Brand new batteries, new 500A controller, new solenoid, cables, motor, etc. When I say new, everything minus the batteries are about 3 years old at this point, but have no hours on them. The batteries were replaced Saturday. Still drops to about 2mph going up my driveway.

Tested the POT and it seems to test out fine, but is it possible to have a bad POT that tests ok? Also, anything else I can look for? For example, the microswitches on the back of the F/R switch? Could it be a problem, thinking the cart is always in Reverse? OR does the fact that the POT tests ok eliminate that as an issue? Need some help.