Excellent stuff. I will jump all over this tomorrow morning. I'll check Fuel Pump and B- Latch Relay as well........good thought. Way past midnight now so I'll report back later. Again, thanks for the time and effort in helping me with this. I wouldn't have a clue!!!cars in general 1980 to present and for sure 80 to 96
had vastly different spark systems, and hard to track lacking a matched FSM book, so do not worry this., at all we can do the tests
keeping mind my 88 was sold in 1999 a very long time ago and had to refresh my memory.
first those readings
A yellow to B blk is power and ground a tad low but ok. 12.6vdc is normal full charged battery but what does A to B do cranking, 11vdc is ok 10 is low limit
below is bad.
you get 10v(9.9) so battery is weak. it need to be kept charged and must be a good battery I cant hear the starter spin fast or slow, so no judge me.
B1 to 2B
well b1 black is ground
2B is ECU sparking signal. (and spark timing ) .2 is not possible to evaluate. ever meter on earth made read 5v pulse differently, and LED test lamp is best or scope you dont have.
A 5vdc LED will flash on 2b(orange) to ground (LED plain, needs resistor to do that. a 150 ohm resistor and LED in series as a test lamp
anode of LED must go to pin 2b. or it can never flash.
will allow a human to see the 5vdc lamp flash. in the blink of an eye fast. LED are fast. so works. ( a scope shows the actual square wave) easy as pie.
the B+ relay. latching.
the schematic shows
B+ has 4 pins (relay) PK,BK,PK,RD
pk is pink and RD is red and BK is black
as you can see C8 is fusible link that must not be blow out.
and is battery + from the starter.
the RD wire goes to relay
the ECU wakes up. and and pin 1 on the relay goes hot. and make ECU fully work, latched.
View attachment 122512
the relay is here, per this page 2.
View attachment 122513