Resistor Coil Test?

[OptimusPrime]

I have a 1988 Marathon and changed the 6 - 6V batteries and its better but still real slow on a hill. Real slow. Is there a way to test the ohms on the resistor board without it accelerating (ie jacked up off floor)? Also, pedal seems to possibly have wiper board issue, where is the wiper board located?

I just got this cart and trying to fix it up, its been sitting and hasnt been used for many years. I ordered the OEM manual and 4 Ga cables for it from BU. Wondering if I will need to replace the wiper board and the resistor, but would rather diagnose than be a parts changer.

[3WheelDumbo]

These old guys are gonna be slow that's just how they are. You can go through my thread on everything I have had to rebuild over the past month since I got mine pics are there for reference, here:
http://www.buggiesgonewild.com/membe...t-3-wheel.html

The ohms on the resistor coils are little to none, but if the cart is not smooth or seems to have only one or two speeds you can remove the coil box and look at them. If its the speed control board it will be right in the center against the front seat wall, this is what makes the contacts from the batts to the motor also an easy visual check.

The beauty of these is easy visual inspection and if its bad it shows it. Also easy to repair but they are not fast and they do burn up the gogo juice do to the resistor set up.

Welcome to BGW, the gurus will be around soon to help I'm sure as they always are. hope this helps

[OptimusPrime]

Thanks for the help 3WheelDumbo. I appreciate it.

[jdunmyer]

OP,
When you're going up a hill, you probably have the pedal all the way down. If that's the case, the resistor coils should be completely shorted out, IE: not in the picture at all.

As 3WD says, you can visually inspect the system and pretty much tell if it's OK or not.

Remember this: heat is bad! Run it up a hill and stop at the top, then check all the connections on the big wires for heat. ALL the connections; none should be more than slightly warm. Check the wiper on the speed control to be sure it's making good contact and not heating up.

Fix any and all hot spots.

If you want to get real scientific, connect your voltmeter in approrpiate places, starting with across the battery pack. It shouldn't drop much below 34 volts or so if your batteries and connections are up to snuff.

[OptimusPrime]

All the wires stay cool except the two in the back on the resistor box going to the motor. they are smoking hot.... Connection, cable or the resistor?

[3WheelDumbo]

OP, does the pedal stick in any position and do you here any arcing??? (referenced to your previous questions) Do you have full speed control (slow, medium, faster and max)?

For your last post, as mentioned previously if you were running it with the pedal all the way down it would bypass the resistor coils and run straight to the motor. The wires you described are the full on position. Your description of hot wires sounds like it could be either the wire size or connection. Small wires get hot and loose connections weld stuff. Look at the wire diagram in the sticky's and it will help you see where everything goes.
http://www.buggiesgonewild.com/elect...rt-wiring.html

If the coils are burnt and open you will not have any power applied to the motor until you have the pedal all the way down and then only run through the wires you described. Too check the coils, the easyiest way is to romve the toaster looking thing in the middle under the seat with the 4 wires connected on top of it from the speed control board (swiper board). It has 4 bolts at each corner where it attaches to the frame. Once you get the toaster out, it will have another toaster box inside of it, remove the 4 nuts from the corners of the resistor coil board and it should come out. Then you can see if they are burnt or not.

The swipper board should have a plugger thing connected to a wire that swipes over 5 different contact points each one passing power through a different position on the resistor coil. If the plunger is not connecting level to the contacts.... no power

[jdunmyer]

All the wires stay cool except the two in the back on the resistor box going to the motor. they are smoking hot.... Connection, cable or the resistor?

If the wire is at least #6 in size, which it will be if no one changed it over the years, it's "big enough" that it shouldn't get hot. When the pedal is all the way down, the resistor coils shouldn't be in the circuit, they should be bypassed. If you look closely at it, you'll see how it works. That leaves the connections.

All connections have more or less resistance; resistance causes heat when current flows. More resistance -> more heat. As a connection heats & cools, it tends to develop more resistance, leading to more heat, and eventual catastrophic failure. That's why it's so important to fix hot connections immediately. Bad connections are caused by either looseness or corrosion, sometimes both. The cure is to take the connection apart, clean it thoroughly, put it back together using some kind of grease, and tighten it properly. Note that it's entirely possible to over-tighten battery terminals.

You might also find that a hot connection is caused by resistance in the crimped-on eye on the end of the cable. The fix for that is to cut off and replace the bad end. Harbor Freight sells a hydraulic crimper that does a fine job, but you also need to use shrink tubing or somesuch to prevent future problems. I used a product called "Rescue Tape" when I made up my cables.

Again, it's hard to emphasize enough how important it is to fix hot spots immediately. A bad connection on the motor can cause failure of the motor itself, something that's rather expensive. Note that you need to use 2 wrenches on motor terminals to prevent spinning the bolt in the insulating washers.

3WD gave you very good advice on the resistor speed control setup. Although many here malign this configuration, it has worked well for years on many thousands of golf carts. If the wiper makes good contact and all connections are in good shape, there's no reason it won't work well for years to come. It does waste some power when you're driving at less than WOT.

[OptimusPrime]

JD and 3W,

Thanks guys your awesome. I'm going to check it all out tonight for sure. It's actually pretty cool having this old toaster project. I'm going to have to start taking some pictures of this as I fix it up and repaint it. Whoever owned it before painted it a flat black over the original green, added a seat over the bagwell and a big foot mount with a grommet in the middle for some crazy flag flying I guess. Just enough to get you pulled over in PTC's hundred or so miles of public cart paths. But you can bet I'll have a big American flag flying on it come July 4th alongside watching the big parade.

[rib33024]

Not all resistor coils are in the middle of the cart in front of the motor, yours could be on the driver side of the cart right next to the driver side rear tire, bolted to the frame just behind the rear battery on the driver side

[jdunmyer]

My old Legend cart had the coils mounted on a board that was situated between the batteries, right at the front of the battery compartment. The wiper swiped contacts on the other side of the board; the F/R switch was just a couple of inches away. Everything was nice and compact, but it did cut the ventilation a bit around the coils. We would ride the cart for extended periods, cruising at slow speeds through the campgrounds, and I could feel the heat escaping from under the seat if I put my hand near a small opening.

However, I used the cart for 12 years and it worked well. IIRC, the only repairs were: a new solenoid, and one micro switch. Another micro switch caused rare trouble that I "fixed" by squirting some Corrosion-X into it.

When I first got the cart, I had to replace the motor gasket and weld up the battery trays. Kept 'em painted and everything was cool during the rest of my ownership.