why is their a resistor wire going to voltage regulator in cluster?

It's not a voltage divider, it is the first half of a voltage summing circuit. They are similar, but when you are summing voltages it is ok to use more of a high end soak than a hard clip.

 

Interesting, thanks for the explanation.

 

The rate of pulse is directly determined by the current going through the ICVR, which directly determines at what point in the voltage curve the contacts activate releasing the correct voltage amount. The ICVR is a crude PWM device after all.

http://www.ford-trucks.com/forums/1197148-icvr-thoughts-and-observations-3.html

I didn't do a good enough job the first few times. Figured I'd try harder. I've been working on an interface to get fuel usage data out of the stock control system for about a year now in my spare time. If I could afford to get that stupid mechanical to digital speedo converter I'd be a LOT further along than I am now. Also, still saving up for the arduino kit to do it with. Only thing I've been able to do so far is digitize the fuel sender data. I got about halfway through a full decode of the signal sweep before I got hung up on the cash.

 

so if the resistance wire is only there as a protection for the regulator, the resistance of the wire does not need to be exact. am i thinking this right?
is their a voltage range i should be checking for at the plug terminal after the resistor wire or will i be ok with just having a length of resistor wire before the regulator (about 1 ft right now)?

 

I have used radio shack resistors in place of the resistor wire in several instances with no issues. 8-10 ohm should do the trick if the previously stated resistance is accurate. An ohmeter would give you an exact number if you have the full length of wire.

 

Actually the resistance wire is only there to keep the heat profile of the entire circuit down. So no, it does not need to be super exact. Basically, as long as you pop in a resistor within 20% you should be fine. I doubt any of us running a stock wiring harness are any closer after all these years. Even that museum car that keeps going up for sale, I'd bet is closer to 10 ohms by now.

 

I wouldn't go lower than factory but 10 ohm should be fine... Main thing to consider is heat from the resistor will be concentrated in one area vs being spread out along the wire for a foot or two(Ever grabbed on to one of those Chrysler ballast resistors that hung on the firewall when in operation?)... Still this circuit is drawing less current so a 10 ohm @ 10 watt resistor should be able to dissipate the heat...

 

I would bet it doesn't generate much heat at all since they used a wire taped up in a harness.

 

Yea, probably a chromium wire, which in addition to resisting electricity very well soaks a ton of heat vs copper which does soak heat well at all.

So yea, use a quality resistor, or just get a new resistance wire.

And @ Krazy Comet: I haven't grabbed one of those, but I have burned myself on numerous F-series and Bronco headlight switches because I swear every redneck truck I've ever been in the dang knob just falls off...