1991 par car coils going bad

[tew45]

when you step on the gas you should have 12 volts at the micro switch and the start solenoid. If your meter is correct the voltage is too low except at first press on the gas and just when you release the gas. Something is drawing the voltage down during full load. Bad battery connection, bad ground connection, bad battery, or incorrect wiring. Check voltage across the battery when trying to start.

[gdoginc]

Could the starter be drawing it down?

[tew45]

It is possible. Do you have any extra load on the starter, like a tight belt? What is the voltage on the battery itself during start?

[gdoginc]

The voltage at the battery remains at 12 V. I have 12 V at the Micro switch. The small terminal at the first solenoid that connects to the coil only has 9 V. I checked at the key switch and it seems to have 12 V when I step on the gas.

[tew45]

There is only one solenoid and that is the starter solenoid. It should have 12 volts on the small terminal when you push the gas pedal and activate the micro switch. If you have 12 volts at the micro switch and 9 volts at the solenoid you are losing the 3 volts at the micro switch or solenoid. check on both sides of the micro switch if you are losing voltage after the switch suspect the solenoid. Or bad connections.

[Boph]

Any luck? I'm having the same problem, 8.2 volts on top of the coil when turning the motor over, and only one spark right when you push the pedal. I checked my ground strap to motor and it seems fine, cleaned it up just to be sure, please let me know if you get it figured out, I know it's loosing ground but I cannot figure out where

[Lochlin]

Guys,

With phantom electrical issues I use the below procedure in an effort to locate the problem. Some of this you already did but all the steps are here. For the most part, if at any one of these test points the voltage drops from the previous test point then you know that you have an issue between there and that previous point.




With your multimeter find the DC setting or settings.


Hold the black wire to the - terminal on the battery and the red on the + terminal. You want to have 12v or a bit above.

If that’s good then keep the red on the battery and move the black to a bare part of the frame. You should get just about the same reading as in the battery

Next move the black to a bare part of the engine. You should still have about the same reading as on the battery.

Now take that black wire and clip it or stick it in a crevice somewhere on the frame so you still get the 12 v reading if you hold the red to the + on the battery.

Next follow the + wire from the battery down to the solenoid. Put the red multimeter wire there and you should still get 12v.

Next check the small rectangular device with 2 terminals that is next to the solenoid. This is a circuit breaker. Both terminals should read 12v with the red wire of your meter. If not your circuit breaker is bad (these don’t go bad often so this is unlikely).

From there take the red wire and touch it to the small terminals on the key switch. Should be 12v there if not you have a wiring problem between the circuit breaker and the switch.

The key switch has to be switched on from this point forward.

Touch the red multimeter wire to the single wire on the gas pedal micro switch. You should have 12v if not your key switch is bad or you have a wiring issue.

At this point you need to activate the microswitch by pressing down on the accelerator. Spin the drive belt off before you do this in case your cart suddenly springs to life. With the accelerator pressed test the other side of the microswitch (the side with two wires attached to it). You should have 12v here if not your microswitch is bad.

Next, take that red wire and put it on the + side of the ignition coil and you should still have 12v. If not you have a wiring issue from the microswitch to the coil OR your electronic ignition module is bad.

From there, take the red wire and check the small terminal on the solenoid. This should also be 12V.

If that’s good then check the other fat terminal of the solenoid.

If that’s got 12V then you are up to the fat wires on the key switch. If you have 12v there then you probably have an issue with the starter / generator. If that's the case you probably want to start a new thread to troubleshoot it.

[gdoginc]

I followed your suggestion and checked the wiring in order. I have 12 v through everything until I get to the solenoid, then I have about 10 at the small terminal and 12 at the large terminal. I disconnected the wire from the microswitch and still have 12 at the wire. As soon as I connect it to the solenoid and step on the accelerator I have 10. I disconnected the starter and it still only has 10. When I try to start it I get about 9.5 at the coil. I finally got it started by stepping on and off the accelerator quickly and then I had 12 at the coil and solenoid while it was running. As soon as I let off the gas and shut it off, I was down to 10 again. Should I suspect the solenoid. What are your thoughts?

[Lochlin]

You narrowed things down a bit so that's good. Thinking of your circuit, your issue should be from the microswitch to the solenoid then to the key switch.

I would do the basics first:

Make sure the grounds at the solenoid and key switch are clean and tight. Make sure the wired connections at all of these points are clean and tight. Pay close attention the key switch connections. Those connections are very close together and it's easy for one wire to touch another back there. Make sure no wires are touching. Even the slightest touching will cause issues. Make sure no wires are frayed back there too.

If that doesn't work then run temporary wires between all of these points to make sure a wire didn't crack under the insulation.

If that doesn't work then you may have to try replacing some stuff. I like to go from least to most expensive for obvious reasons. In your case the solenoid then key switch.

Hopefully, others will chime in too. I am no where near as knowledgeable as some of these guys.

[Lg96gt]

Wildride, did you ever find a solution?

Originally Posted by gdoginc

My ignition switch works as it should. Nothing happens until I step on the gas. When I step on the gas it makes 1 or 2 sparks and then no spark. If I hold the gas down there is no spark. It sparks again when I let the gas pedal all the way back. It seems to only have spark when you first step on the gas pedal and let off the gas pedal at the end. I tried a new ignition module and then I have absolutely no spark at all. I tried a new coil and that makes no difference. I checked the voltage at the coil when it is turning over and I have about 9.5 volts. If I run a jumper wire from the battery to the coil it still won't start and I have no spark at all. Any thoughts?

The above described is almost exactly where I am at. Picked up my car not running last week. New top end, cleaned carb and it's alive for the first time in 5+ years! After about 3 hours of use it quit, did some investigation and find I get one quick spark when I let off the pedal...this happened Saturday afternoon, this afternoon (Sunday) after verifying all connections are tight and doing nothing else it took off until it got warm and died again. Same thing one spark after letting off the pedal. Metered the coil and the secondary was about 9700 ohms. Threw it in the freezer for 20 minutes and it came down to about 8500. Still no spark. Ended up metering around and eventually without changing anything it cooled off enough and started firing again...I'm thinking either solenoid or coil at this point. Thoughts?

(P.a. What size resistor goes in the key switch between Orange and gray?)