1983 36v Textron. One speed only - HIGH!

[TheDude22]

Hello World! I'm a brand new member (a few days now). I have a fair amount of auto mechanic experience and am an avid DIY'er. I've been searching the forum looking for tech advice, but haven't found much regarding my particular issue. I bought a 1983 Textron a couple of weeks ago for a utility vehicle around my property. The problem is, when I step on the accelerator pedal, the cart peels out! There is no low or medium speed. I can adjust the position of the pedal, but the cart has only one speed - High! This cart has an accelerator switch and resistor coils, not an electronic speed control. So far, I've checked the solenoid - good, checked the wiring for the entire cart - it seems to match the schematic. Replaced the spring loaded brush for the wiper arm (accelerator switch). Polished the copper contacts on the accelerator switch. I checked the resistor coils for continuity and resistance (about 105 ohm through all resistors). The batteries/cables were replaced by the previous owner in December 2019. Does anybody have a clue as to what the issue is here? If it goes from zero to high as soon as the wiper arm brush touches the low speed terminal, it would seem as if there is little to no resistance through the coils, but like I said, the coils have continuity and resistance. Any help with this would be much appreciated.

[JohnnieB]

Something isn't wired right.

Disconnect battery pack.

Connect ohmmeter between the solenoid's large terminal that has cable connected to wiper and the A1 stud on the motor.

Should have max Ohms (105Ω ?) when wiper is on stud-1 and progressively fewer Ohms on studs 2 & 3 and 0Ω on stud-4. (Note: pedal up has wiper on stud-0)

[Andy4639]

More than likely they wired the coils in backwards per your statement.

The batteries/cables were replaced by the previous owner in December 2019.

[TheDude22]

Thanks much for the replies. I'll finally be able to check it out today (long days at work, right now). As far as the coils go, the low speed cable (first wiper contact) attaches to the end of the thinnest diameter coil. The coil diameters get progressively larger with the largest connecting to the high speed cable. It seems as though this is correct, the largest diameter creating the least resistance. Right? Does anybody know how many ohms resistance should be created by the coils?

[TheDude22]

Okay! so I finally was able to actually troubleshoot the "high speed only" problem. Here goes: I began by doing what JohnnieB suggested. I checked the resistance between solenoid and A1 on the motor (with batteries disconnected). Zero ohms. I disconnected the resistor coil pack, disassembled it and checked resistance of each coil. First of all, I was full of it when I said it had a resistance of 105 ohms. I checked each coil: low speed coil =0 .3 ohms, medium = 0.2 ohms, high speed coil = 0.1 ohms. In series, they measured 0.7 ohms. I guess when I measured them originally, I must have had a poor contact (rust?). So, with this information, I should , as JohnnieB indicated: have a minimum of 0.7 ohms between solenoid and A1. Again, I had zero. Anyway, I then began to check the resistance between each of the copper contact studs on the wiper board. Zero resistance between them! That's when I noticed that someone had added flat washers to each copper contact stud. These washers were making contact with each other. The incoming power was completely bypassing the resistor coil pack all together! I simply removed the washers and voila, success. I've now got variable speeds. I hope my trials with this will help someone in the future. Thanks again JohnnieB and Andy for the advice.

[JohnnieB]

Thanks for the feedback.