91 Marathon controller cart won't move F/R

[crackers450]

Hi Guys,
I bought another Marathon this 1 is a controller cart not resister like my other one, fitted batteries and charged up, getting 39.6v on terminals now but cart won't move, getting click from solenoid both F/R also reverse buzzer is working but no movement, connected DVM to B-& M- terminals on controller & I don't get full voltage when pedal pushed to solenoid click only 6.7v what could the problem be please, F/R switch if so how can I fix this???
Cheers
Laurie

[JohnnieB]

Not getting full pack voltage between B- & M- when the solenoid first clicks means you've got high resistance in the high current loop.

Connect the negative test lead of your DVM to the B- terminal on the controller and start moving the Positive test lead from M- to convenient test points closer to the main positive terminal on the battery pack. The fault will be between the last place you had 6.7V and the first place you had full pack voltage.

[crackers450]

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Thanks a bunch JB I will try that today the photos are of the carts electrical system, ignore the red wiring it's all to do with the lights and the way they were set up, I will get it moving first then work on tidying it all up

Cheers
Laurie

[simple man]

In your top photo the rear battery on the left side has a doubled red cable going to the battery post. Is that in place of a battery cable? If not, you don't have one of your battery cables connected.

[crackers450]

JB,
That cable has now been replaced with an original, I never received a key with the cart so I think it was the DPO who connected an isolation switch through that wire, I had a spare key so I removed the switch, I still cannot get it to run, any ideas? It is starting to annoy me, I have followed some of the ideas on the forum but it is confusing to say the least

[crackers450]

ok checked the voltage between positive post & negative post & got 39.3v
negative probe left on negative post, turn key on into forward gear, checked voltage on B+ side of solenoid with Pos side of probe got 39.3v, checked controller side of solenoid with Pos probe got 34.3v (5v is this a problem ???), take & label cables off motor to check continuity between S1 & S2 all OK, check continuity between A1 & A2 nothing, there is no continuity between any A or S terminals, what could be the problem ? will it be the motor is shot, or just a wire inside casing ( i hope) can anyone tell me ???, if the motor has to come out is there anywhere on the forum that explains the procedure (1991 EZGO Marathon solid state speed control)

Cheers
Laurie

[JohnnieB]

No continuity between A1 & A2 means an open armature. Could be a broken wire from the stud to the brush, bad brushes or a bad armature.

Only three bolts hold the motor on the differential, but the splines in the motor shaft will most likely be rusted onto the mating splines on the differential shaft, so it probably will be difficult to take the motor off.

[crackers450]

OK, undone the 3 bolts holding the motor to the diff, shook the shite out of it & it came loose, took the motor into the shed and pulled it apart, broken wire on the A2 stud, little gas torch & hey presto soldered it back together, now the main problem how do you get the 3 screws in the center of the casing back onto the plate behind the bearing??, I can't seem to find the screw holes in the plate through the casing, as soon as I do I can bench test the motor & then refit it to the cart

Cheers
Laurie

[JohnnieB]

You've probably got it together by now, but I had pretty good luck using 6" bamboo skewers to line up blind holes when assembling stuff.

[yurtle]

If you mean chop sticks, I've done the same trick.