for the mk1 172 conversion boys

[geesus69]

right, just doing the last bits to mine before its ready for some track outings

i have a sparky friend who last night started tidying up all my wiring

basically i would like to know:

a) is there any way of getting the standard valver coolant gauge to work without tapping the mk1 sender into the thermostat housing?

b) what exactly do we need to connect to get the mk1 tacho to work, he connected what he thought might be the correct signal last night, but it didnt budge (i remember matteh saying my car already had the 'mod' to get it reading the right engine speed and not under reading by half)

thankin you

 

[geesus69]

i think i might have the tacho bit sorted

your clocks have been modded already so just plug the correct wire from the clocks (pin 13 on the large connector behind the rev counter) into pin 70 of the 172 ecu.

and i think you can only get the temp gauge to work by drilling and tapping the mk1 sender into the thermostat housing

answering your own questions ftw

 

[Mark One]

this thread is so lonely



.....

 

[geesus69]

this thread is so lonely



.....

lol

i was maybe a bit to eager with this thread

unless someone is going to tell me you dont have to use the mk1 temp sender?

 

[f0xy]

yes you tap the sensor into the side of the housing, mk1 item, and run the wiring for it

for the tacho you take one of the coil signal wires, splice off it, put in a 10k resistor pullup (one side of resistor on the signal wire, one side going to a 12v live), then run the signal wire all the way back to the clocks.....and itl be spot on

 

[f0xy]

Mk1 sensor in, two compression/sealing washers, and a thin stainless nut on the inside with some nylock/threadlock.... sorted

 

[geesus69]

sound job, cheers foxy

 

[Matteh]

you need the mk1 sensor as it controls both the warning light and the analog gauge

also worth using some silicone gasket

its pin 70 that you need for the rpm signal.

*apparently* your clocks already have the 10k resistor wired up, as the car was previously running on standalone


repeated info ftw

 

[geesus69]

its pin 70 that you need for the rpm signal.

*apparently* your clocks already have the 10k resistor wired up, as the car was previously running on standalone


repeated info ftw

im going to leave the mk1 gauge for now then, i have an aftermarket gauge that also controls the fan so i can do without

i will try pin 70 tonight and see what i get

 

[geesus69]

i presume the issue when tapping into the ecu coolant output is the constant running fan?

or are there more issues than that?

 

[Matteh]

there isn't an ecu coolant output is there? the clocks take their feed from the sensor. the ecu outputs the light control i think?

easiest to install the mk1 sensor as it works with the light and is calibrated for the mk1 dash too

also, you don't have to mix signals

 

[Matteh]

than fan will run constantly if u unplug the mk2 sensor... hence run them in parallel