Today my Harlan RPM switch decided to go nuts. As most of you know, my Harlan RPM has been pretty much flawless ever since I stopped using a relay 5 months ago. Today, the switch decides to puke. Cruising home I notice that I'm not hearing the switchover (set for 5000). I pull over, open up the RPM switch case and sure enough, the red light is flashing. I turn the car off, then turn it on again, and the RPM switch acts normal. I accelerate in 1st to engage the switchover, then it starts to flash again and the VI doesn't work. I reprogram the whole switch and confirm the settings. Now, when accelerating to the switchover point, NOTHING happens. No lights, no VI, no nothing I set the RPM switch to 4900rpms and it works flawlessly three times so I figured it was working. I get home, reset it to 5000rpms and go eat dinner. After dinner I take another spin, wind out 2nd, hear the VI switchover, hit 3rd hear it. Back down in 3rd and go again. Nothing. I set it to 5100rpms and it's flawless. It activated 10+ times in row at in different gears. Set it to 5000rpms and it gets confused. Set it back to 5100 and it's fine?!?!?! The only other time it had become confused without the relay was about 2 months ago. It messed up once and then it was fine. Today was totally strange.

It's so damn frustrating. The setup is SO SIMPLE yet it continues to have problems.



Dave

 

mine flaked out the other day for no reason as well, I reset it and it has worked fine again. Mine is still set at 5000 rpm. I noticed it didn't open, and I checked the switch and it was blinking.

 

Dave

 

geez, i didn't even head bang that much at the metallica concert i went to a couple years ago.






g0t adviL ?

 

It's working fine now and you aren't allowed to touch or look at my car.


Dave

 

Trevor gets

 

but but but.....paleeeeease???

 

:cough: MSD :cough:

 

is there any alternative to the Harlan?

 

MSD switch $90
MSD RPM "pills" $30
Send the MSD unit off for reprogramming $60

$180 for an RPM switch?



Dave

 

It's the price you have to pay for 100% reliability. We could all be driving a YUGO....

 

I have 3 Harlans and they're reliable
-hype

 

To have it flake out for a few minutes every few months isn't much of a big I guess. I'll just be sure to reprogram it at the track to make sure it works everytime and I'm going to solder all my connections this week for safe measure too. I don't feel like spending $180 on an RPM switch for 100% reliability. 98% reliability will suffice for now.


Dave

 

exactly my thoughts.

 

3? can I have one

 

I've got two. My Harlan shiftlight (same exact thing as the RPM switch) has been flawless. I'm going to go ahead and wire the RPM switch to get the signal off the coil pack. I might also find a better ground and 12V power source. Weekend project time.


Dave

 

Also, if you want and you don't care about the warranty, try using the shift light. I did not have the RPM switch at the time I installed my VI, so I took my Harlan shift light, cut the ground wire going to the LEDs, and ran the ground wire from the switch (not LEDs) and ran it to the VI. It has worked everytime for me with and without the relay. But, I just got my RPM switch the other week, so I will be installing that off the coil pack in the engine bay.

 

NEVERMIND, I just read the rest of the post and saw that you got it working correctly now. I have been

 

lol warranty
"Operation is guaranteed for 90 days after date of purchase.
No other claims are made about this product, explicit or implied."

I do believe that the coil is a better place to tap than the ECU, but I'd keep the Harlan in the car if at all possible.
-hype

 

True, since Bags533 kept his in the engine bay, opened it up, and water came out of the switch....

 

Really, I must have missed that. Maybe I should relocated. Hmmmm......

 

I do have it tapped into a coil, but my switch is inside the car in the fuse panel. I have the wires long enough to where I can pull it out and look at it when I am in the driver's seat.