87 to 90 wiring harness

[dougie30]

If I where to buy a motor from a 90 would the 87 wiringharness plug right into it, i am asking because i have an eta motor and want to do the i swap but dont want to have to mod the 90 wiring harness and can get this motor for pretty cheap.

I know the whole 87 engine and harness plug right in because they have the same pins in the c101 connector but i cant find an 87 i motor.

please any help is appreciated.

[dougie30]

btw i have researched ALOT couldnt find much

[MR 325]

I assume you mean the 87 i harness in to the 90 i engine?

It will all plug in except for the oil level sender and oil pressure switch. Both are easy to swap though.

[dougie30]

yes that is what i meant.

and how would i go about getting the sender and switch into the harness? cut and splice from a newer harness? or would it be easier to just modify the 90 wiring harness to work with my car?

im not sure the easiest way of going about this, not very good with wiring.

[Will_NZ]

Does your eta have ABS?

If not, check pin#20 of the C101 on both plugs. The later loom is likely to have a red/yellow wire at pin#20 which supplies power to the ABS and the eta is likely to have a brown wire (ground) to pin#20. If you just connect them up, you will have a fire..

[dougie30]

i do have abs, and do you mean fire as in piston cylinder fire or my whole car goes boom fire??

[jlevie]

i do have abs, and do you mean fire as in piston cylinder fire or my whole car goes boom fire??

That triggers the secret built in self-destruct mode. The entire car melts down!

Serious all that happens is that you smoke the engine harness the first time the main relay closes. The best way to deal with this possibility if there is wire on the body side at pin 20 of C101 is to cut it.

Deal with any differences in the oil pressure or level sensors by changing those parts to ones that match the harness.

[MR 325]

Deal with any differences in the oil pressure or level sensors by changing those parts to ones that match the harness.

x2. Both are very easy to change.

[dougie30]

That triggers the secret built in self-destruct mode. The entire car melts down!

Serious all that happens is that you smoke the engine harness the first time the main relay closes. The best way to deal with this possibility if there is wire on the body side at pin 20 of C101 is to cut it.

Deal with any differences in the oil pressure or level sensors by changing those parts to ones that match the harness.

hahahah, ok but if i were to cut the pin 20 which gives power to my abs, then that means my abs wouldnt work??

and this applies to all late wiring harnesses 87 to 92?

[jlevie]

hahahah, ok but if i were to cut the pin 20 which gives power to my abs, then that means my abs wouldnt work??

and this applies to all late wiring harnesses 87 to 92?

The reference to ABS is a red herring. It has nothing to do with pin 20 of C101. Only late production that pin was part of the SRS system.

[TobyB]

Yeah, +1 on 'Its not ABS at all'. I put a late '90 motor into an early 87, and had to
cut the green bodyside wire.

...you'll probably have to move the Gasometer and Tachometer wires out of the 3- pin
connector, too.

Search "C101" for a bunch of very pertinent posts that have more info than any 3
r3vlimiters know what to do with...

t

[dougie30]

ok cool, so if i cut the pin20 wire on the body side, and get the right oil pressure and level sensors, then i should be good for my car to start??

and if i have to move the gasometer and tach wires out of the 3 pin connector, where do i put them after?

sorry if i sound like an idiot, i litterally dont have any clue about wiring or the harness, im better at the mechanical aspect of things haha

[jlevie]

If you use an 87 M20B25 harness, you won't have to mess with the wires for C104 and shouldn't have to mess with C101. But if you use a later harness you will have to deal with those.

[dougie30]

If you use an 87 M20B25 harness, you won't have to mess with the wires for C104 and shouldn't have to mess with C101. But if you use a later harness you will have to deal with those.

ok thats good, but what if i use the 87 wiring harness, with an 89 engine? thats what i was wondering.

or do you guys think i should just get the whole 87 engine and harness combo?

[jlevie]

ok thats good, but what if i use the 87 wiring harness, with an 89 engine? thats what i was wondering.

or do you guys think i should just get the whole 87 engine and harness combo?

You can use an 87 harness with any M20B25 engine, though you might have to change the oil pressure and level sensors to match the harness.