Blower Relay and Tail light Relay connections to 4age 20v ECU.

[paulv]

Am in the process of wiring a 4age 20v Blacktop ECU.

Having to kind a do it from scratch as am installing the 20v into a Suzuki.

Found all the info on the net as to what each terminal on the ECU is for... Some one has made a scanned copy of a Blacktop services manual available.

However, don't really understand a few of the connections.

On the 26 pin ECU plug there is a Green wire "ELS3" that aparantly connects or relates to the Tail Light Relay?
WTF? does the ECU need to know when the tail lights are on?
What for? Should this be negativly or positvly switched?

On the 26 pin ECU plug there is a Blue Red wire "ELS2" that aparantly connects or relates to the Blower Relay?
WTF?
As in the heater fan in the dash?

The 16 pin ECU plug has a black wire "ELS4" that has something to do with a Defogger swith?
Defogger? as in windscreen Defogger?

The 22 pin ECU plug has a Yellow Red wire "AC1" and a Red Blue wire "ACT" that has something to do the the Air Con?
Am assuming the compressor clutch is swithed via the ECU?
Which connection does what?


Any ideas? comments?

[Matt]

I've never bothered with the idle ups els## as it can mess with the idle. It'll run fine without them.

As for ac use whatever the Suzuki has to control it and give the ecu 12v when the air con is running. Done this many times in ae92's etc

[Golberg]

ELS = Electrical load sense

Basically they are there so that high electrical loads can be compensated for using the ISCV. Because the alternator loads the engine up, and as such pulls the idle down a little. Using the ISCV the ECU is supposed to compensate for this and bring the idle up to spec according to what it sees on the ELS terminals. The ELS's are not necessary, you'll find that your loads aren't great enough to make much difference, but in a perfect world you'd connect them up. They expect a 12v+ input.

I can't tell you off the top of my head which one to use, but again the ECU expects a 12v+ input to signify that the compressor clutch is engaged and subseqent idle compensation required.

[paulv]

Thank you gentlemen.

Makes sense now - thank you.

I will the leave the 4 ELS connections blank - unwired for the moment.
If it idles poorly when the high current devises are turned on, I will think abour wiring it in then.

Again thank you, appreciate the comments.