 Working with Relays, A little help understanding... |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
| malaga_red75 |
 Jul 15 2009, 04:19 PM
Post
#1
|
|
'74 2.5L N/A Subie  Group: Members Posts: 454 Joined: 5-March 06 From: Menlo Park, CA Member No.: 5,674 Region Association: None  |
So I am using aftermarket relays for the fuel pump and the cooling fans on my subaru conversion, using the stock ECU. I have attached a picture of the relay diagram.
 So, there are two circuits, an 'inner' circuit and an 'outer' circuit. The outer circuit is only completed when the inner circuit's electromagnet is active. It is currently wired like this: The 'inner circuit' receives a signal from the fuel pump pin on the ECU which goes into terminal 86 on the relay. (and here is where i think it has been wired wrong), coming out of terminal 85 the wire goes into the ECU into a 12 volt power connection. This is for the 'inner' circuit which should ignite the electromagnet. --- I THINK THIS IS WRONG. ---Shouldn't the wire coming out of terminal 85 go to a ground? thus completing the inner circuit and cause the magnet to attract the arm to complete the 'outer' circuit. I hope that wasn't too confusing, let me know. Thanks a bunch! -Peter |
   |
 
|
  |
Replies
| busmech |
Jul 15 2009, 09:49 PM
Post
#2
|
|
Member Group: Members Posts: 68 Joined: 12-April 09 From: Daly City Ca Member No.: 10,258 Region Association: Northern California |
85 and 86 does not matter which one is pos. and which is neg.
Most ecu circuits are outputing a ground to activate a relay, but some are bat. voltage. You need to find out what you have, conect it to 85 or 86 does not matter, and then the other one goes to a ground or batttery. you should have 30 wired to battery, fuse protected of course, then 87 goes to the fuse pump |
|
|
|
| mskala |
Jul 15 2009, 10:44 PM
Post
#3
|
|
R Group: Members Posts: 1,925 Joined: 2-January 03 From: Massachusetts Member No.: 79 Region Association: None 
|
QUOTE(busmech @ Jul 15 2009, 11:49 PM)  85 and 86 does not matter which one is pos. and which is neg. ... Yes it matters, if you wire it opposite you will get the field reversed which will keep the output from changing ever. |
|
|
|
| Cap'n Krusty |
Jul 16 2009, 09:19 AM
Post
#4
|
|
Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
QUOTE(mskala @ Jul 15 2009, 09:44 PM) QUOTE(busmech @ Jul 15 2009, 11:49 PM) 85 and 86 does not matter which one is pos. and which is neg. ... Yes it matters, if you wire it opposite you will get the field reversed which will keep the output from changing ever. Generally speaking, you're wrong. The relay doesn't care about the polarity of 85 and 86. I'm sure there are diode protected ones out there, but I've yet to run across one. The Cap'n |
|
|
|
Posts in this topic
malaga_red75 Working with Relays Jul 15 2009, 04:19 PM
underthetire
So I am using aftermarket relays for the fuel pum... Jul 15 2009, 04:21 PM malaga_red75 Ok, so that leads to my next question, what would... Jul 15 2009, 08:37 PM r_towle try reversing the way you have it wired to the rel... Jul 15 2009, 08:50 PM
budman5201
try reversing the way you have it wired to the re... Jul 15 2009, 08:56 PM malaga_red75
maybe something is backfeeding? Subaru Idle con... Jul 16 2009, 01:59 AM jt914-6 Maybe this will help......
Jul 15 2009, 08:59 PM r_towle so you wired it backwards.
85 is ground...not posi... Jul 15 2009, 09:01 PM mskala
[quote name='mskala' post='1191964' date='Jul 15 ... Jul 16 2009, 11:04 AM busmech Here is a good explanation of the bosh relays
http... Jul 15 2009, 11:09 PM rascobo
Here is a good explanation of the bosh relays
htt... Jul 16 2009, 12:22 PM busmech Just above the animation there is a paragraph that... Jul 15 2009, 11:13 PM busmech The only time that you need to have a certain pol... Jul 15 2009, 11:19 PM Tom Busmech, you are correct. Unless the relay has a p... Jul 16 2009, 08:20 AM |
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 16th June 2024 - 03:43 PM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.