Hyundai r130 rpm sensor

Got my R130 back together and hopefully sorted the overheating problem. Now I'm dealing with a broken wire on the speed sensor. I grabbed an aftermarket replacement, but it's not reading right. The display goes blank once it hits around 1700 rpm. I set the gap by bottoming it out against the flywheel, then backing off about a 1/4 turn. Getting closer seems to help, but I'm not sure how tight I should really go with it.

Found it in my manual. Insert until contact, then back out 135 degrees.

Tried 135 degrees but it didn't help. Not sure if this aftermarket sensor just isn't good enough or if there's a specific tolerance I'm missing.

Does the speed sensor have anything to do with the travel speed? I've got an R130 that I can get into high range and I'm trying to figure out what might help.

I'm having trouble getting my R130 into high range. Any ideas what might be causing that?

I had the same speed issue on mine. Ended up being the travel solenoid in the back with a broken wire. I don't think the rpm sensor really affects the travel speed though.

The problem with your speed sensor probably comes down to a few things. First, check the gap between the sensor and flywheel—you're aiming for somewhere between 0.5-1.5 mm. Also make sure the aftermarket sensor is actually compatible with your system; if it's not working right, going back to an OEM part might be worth it. Look at your wiring too—make sure it's secure and not damaged, and the sensor wire should be shielded to keep interference out. While you're at it, inspect the flywheel teeth for any wear or debris. Finally, verify that the sensor can handle your engine's RPM range. One of these should be causing your cutout above 1700 rpm.

Looks like I might be connecting some of these issues. I went back and looked more closely at the speed sensor and can confirm I'm getting 5v out of it, but the monitor still won't show a reading. On a brighter note, I finally fixed the handle for climbing up on the bulkhead. Turns out that handle also does some important grounding work. When it's off, there's activity at the ignition. The new one needed the paint stripped off before I put it in. I thought that would solve my tach reading problem, but no luck. Guess I need to pull the monitor wiring and trace through it.

From the monitor to the speed sensor there's got to be some wiring you can test under load. Do you have schematics for the machine? If you do, post a picture or more details and maybe someone can help you out.

The CPU Controller sits at the bottom right of the diagram with several connectors branching off it. I had to blow up the schematic to 250% on my screen just to read the details clearly.

Looking at the right portion of the diagram near the bottom, you'll find the speed sensor. It's got a twisted pair coming out of it. One wire heads up to controller plug CM-52, specifically Pin #14, routing through the CM-2 plug to get there. The second wire exits from the bottom of that same sensor, also uses the CM-2 plug, but terminates at a different location—plug CM-12 on the computer side at Pin #12. That's the best I could make out even with reading glasses and plenty of squinting.

Here's what I'd do to test this. Grab a 5 amp bulb and apply power to one end of a wire—make sure both the sensor side and the computer side plugs are completely disconnected. Ground the opposite end of that wire to the battery. Before you go further though, run an OHMS check on both ends of each wire to verify you're testing the right one. If either end fails the ohms test, you're looking at the wrong wire or there's a break somewhere along its length.

You'll want a load test regardless. Hook up the bulb. If it barely glows or won't light at all, there's an open circuit. If it pulls more current than normal when you check it with a multimeter on amps mode, that means the wire's grounding out somewhere else or shorting to another conductor. Leave that bulb connected and running for about 5 minutes—the heat might reveal where the problem is, or a weak spot could fail.

I knew a guy once who fabricated twisted pair wires like that instead of dropping $5000 on a complete harness, so if yours is damaged, rebuilding it's definitely doable.

Here's a close-up. Planning to tackle this over the weekend.

Start by disconnecting the negative posts on your machine, then unhook both ends of the sensor cable and pull the computer plugs. To check if the wires are sound, take a 5 amp test bulb and run it through each wire individually, connecting the opposite end to ground on your test battery. After 5-10 minutes you'll know whether each wire passes the test or fails. For testing you'll need either a dedicated 12 volt battery or whatever your bulb is designed for. I go with a 9003 bulb rated at 12 volts—it's got dual filaments in a dual wire socket. On my meter the stronger filament pulls exactly 5 amps, which makes it easy to spot problems. If your wire has a ground fault partway along the twisted pair, you'll see some voltage appearing on the pin of the wire you aren't currently testing. From what I've found this is really the only proper way to test whether these wires are working or damaged.

Haven't done the load test yet, that's coming up next. I pulled the monitor off to check the wires and found it—an almost broken wire with only 3 strands still connected. I looked at the wire diagram and it's one of the exterior lights. Why can't anything ever be straightforward?

Even with just a single strand still intact, an ohm meter will show it's fine. That's why using a 5 amp or 10 amp bulb will actually test the wires properly under real operating conditions.

Got the wire fixed and cleaned the monitor and computer plugs with contact cleaner. Engine fired up and the rpm showed, but then it went blank again. So frustrating!

To check whether a ground from the computer is working properly, start by unplugging the computer connector and disconnecting the battery ground. Next, connect a 5 amp test bulb between the computer connector and the battery ground cable. If the bulb doesn't light up at full brightness, that tells you there's a problem with one or more of the ground wires. Keep the bulb running for at least 5-10 minutes so the heat buildup can show you what's going on.

I also noticed my low coolant reservoir alarm went off for that same couple seconds. I'll need to rig up some sort of test setup for the load test. Still need to figure out how to get a pin into the connector though.

Would this work?

For testing, I use an Automotive 9003 Bulb that comes with a 3 wire pigtail connector. The ground connects to one wire, while the other two go to individual filaments inside the bulb. When I measure the Yellow-to-Black circuit, I'm pulling 3.4 amps. The Red-to-Black circuit draws 5.0 amps. If I hook up both simultaneously with Black as the common ground, the total current comes to 8.4 amps when both filaments are lit.

This method works well because you can let it run for 10+ minutes, which gives you realistic heat conditions like you'd see in an actual engine compartment. The results will vary depending on which specific wire you're testing and how the harness is holding up. If something fails during the test, that tells you there's a weak point somewhere that needs attention. Make sure you look at the schematic first.

Loose pins in connectors and partly degraded wires become obvious with this approach. You'll also catch anything that's accidentally grounding against something metal. I typically cycle the power on for a few seconds, then shut it down and check my meter reading to see if the circuit's drawing more than the bulbs' normal load.

Hope this works for you. Feel free to ask if you need clarification on anything.

I got a 9007 from work since we don't make the 9003. Set up a test with some wire and cut 3/4 of the strands. Didn't notice any current drop though. I'm only seeing 1.6A, which is the same as running just through the lamp. I'm using a 12v battery charger for the voltage.