Hello friends, 
Post Message - 30376
I have used the same subject line as my original message 25102 and 
have copied and edited the whole message below - so hopefully people 
will get this message as well as 25102 if they do a search. 
 
I sincerely apologize for the error in my B+ measurement - the fuse 
sizes I had recommended in 25102 will probably work A Ok but if you 
are working in the Black Junction Box - swap the two fuses to match 
the recommended values below. 
 
Based on Brian's very good question in message 30636 I went back and 
re did my current measurements and found that I had screwed up 
something when I did the B+ measurements on my test stand engine. The 
results do not change the fact that the KEP fuse sizes are away too 
large. Here is 
what I measured: 
 
1) Ign On - 93 EJ22 harness arrangement- NOTE - UNCHANGED: 
 
- around 0.2 amp with Ign On, fuel pump cycling but engine not 
running 
- idling at about 500 rpm it was 1 amp. 
- at 3000 rpm it was 2 amps. 
You can see the affect of having the coil connected to this wire (92 to 94). 
 
ADDED COMMENT - the current will be about 1 amp regardless of rpm for 
- 90/91 harnesses and for 92 to 94 harnesses where the coil power is 
from the Ign Relay. 
 
2) B+ -  HERE IS WHERE I SCREWED UP 
 
- Ign ON but engine not running - about 2 amps. 
- Engine running - idle 600 rpm 4.2 amps. 
- 4000 rpm 4.5 amps 
ADDED COMMENT - the current will be about 1 amp higher for - 90/91 
harnesses and 92 to 94 harnesses where the coil power has been moved 
to the Ign Relay. 
- Thanks Brian for raising the flag re the fuel pump current - I 
measured the fuel pump current separately - here are the results: 
- short transient of about 4 amps when pump first starts up. 
- pump running - current varies between 2.6 and 2.8 amps as engine 
rpm increases. So approximately 50% of the B+ current is to drive the 
fuel pump. I would expect this current to increase if you have a 
cloged filter or blockage in the fuel tank. 
 
So as you can see the KEP instructions are not good from a wire and 
circuit protection point of view. I strongly recommend that you change 
your fuses to the following: 
NOTE REVISED FUSE RECOMMENDATION 
IGN ON - 10 A maximum 
B+ - 15 A maximum 
Alt Light - NO fuses is needed in this circuit 
 
I have been getting quite a few e-mails from people who have melted 
their wiring and damaged their ECUs dues to short circuits. I am not 
saying the smaller fuses would have helped but they certainly would 
have blown much earlier than 30 A fuses. 
 
Tom Shiels, 
Burlington Ontario 
http://www.subaruvanagon.com/