What Are These Electrical Devices?: '88 4runner
Jul 31, 2011 | 06:17 PM
#1
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From: S.E. Wisconsin
What Are These Electrical Devices?: '88 4runner
Anybody know what the electrical items circled in red in the picture below are? It's from a '88 4runner with a 3VZE (V6) engine and a manual transmission (federal emissions model). My '89 4runner w/automatic and California emissions has neither of those pieces. Some of it merges with the main engine compartment wiring harness where I indicated with the yellow circle. -- Matt
PS Don't mind the dirt and rust, it's a parts donor.
PS Don't mind the dirt and rust, it's a parts donor.
Last edited by wrenchtech; Jul 31, 2011 at 06:19 PM.
Sep 7, 2011 | 04:58 PM
#4
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From: New Brunswick, Canada
The item on the left is the resistor pack for the injectors (they are low impedence). Your 89 doesn't have the resistor pack because midway through 88 Toyota changed to high impedence injectors, so the resistor pack wasn't needed any longer and yes the wiring for this was in the body harness not the engine harness.
On the right is the starter relay. Automatics do not have a starter relay, the neutral start switch prevents the vehicle from being started in gear. Automatics and manuals use the same starter, so the starter relay is not installed because starting current is so high that you need a relay, but Toyota uses it in manual vehicles as a safety feature more than anything. Manuals do not have a neutral start switch, so Toyota had to come up with some way that a manual could not be started in gear. What they did was to install a relay in the circuit and have the ground side of the coil wired to the clutch switch. By doing this the clutch pedal would have to be depressed in order to start the vehicle, thus it couldn't be started in gear.
A little info about relays, they can be complicated, but a simple relay like the starter relay consists of two sides, a contact side and a coil side. The contact side consists of a stationary contact and a moveable contact This contact can be either "normally open" n/o or "normally closed" n/c. This refers to the contact position when the relay is sitting on the shelf not wired to anything. The contact side carrys heavy current, it's terminals and wiring are always heavier than the coil side. The coil side is an electro magnet which has a plunger that is attached to the moving contact.
For this starter relay if the clutch is not depressed, if you turn the key to start nothing happens, if you depress the clutch, turn the key to start, current flows through the coil, through the clutch switch to ground. As current flows the plunger is drawn into the coil and the contact closes completing the contact path to the starter and the starter engages.
On the right is the starter relay. Automatics do not have a starter relay, the neutral start switch prevents the vehicle from being started in gear. Automatics and manuals use the same starter, so the starter relay is not installed because starting current is so high that you need a relay, but Toyota uses it in manual vehicles as a safety feature more than anything. Manuals do not have a neutral start switch, so Toyota had to come up with some way that a manual could not be started in gear. What they did was to install a relay in the circuit and have the ground side of the coil wired to the clutch switch. By doing this the clutch pedal would have to be depressed in order to start the vehicle, thus it couldn't be started in gear.
A little info about relays, they can be complicated, but a simple relay like the starter relay consists of two sides, a contact side and a coil side. The contact side consists of a stationary contact and a moveable contact This contact can be either "normally open" n/o or "normally closed" n/c. This refers to the contact position when the relay is sitting on the shelf not wired to anything. The contact side carrys heavy current, it's terminals and wiring are always heavier than the coil side. The coil side is an electro magnet which has a plunger that is attached to the moving contact.
For this starter relay if the clutch is not depressed, if you turn the key to start nothing happens, if you depress the clutch, turn the key to start, current flows through the coil, through the clutch switch to ground. As current flows the plunger is drawn into the coil and the contact closes completing the contact path to the starter and the starter engages.
Last edited by Hadmatt54; Sep 7, 2011 at 05:01 PM.
Sep 8, 2011 | 05:38 AM
#5
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Joined: Jan 2009
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From: Graham, WA
The item on the left is the resistor pack for the injectors (they are low impedence). Your 89 doesn't have the resistor pack because midway through 88 Toyota changed to high impedence injectors, so the resistor pack wasn't needed any longer and yes the wiring for this was in the body harness not the engine harness.
On the right is the starter relay. Automatics do not have a starter relay, the neutral start switch prevents the vehicle from being started in gear. Automatics and manuals use the same starter, so the starter relay is not installed because starting current is so high that you need a relay, but Toyota uses it in manual vehicles as a safety feature more than anything. Manuals do not have a neutral start switch, so Toyota had to come up with some way that a manual could not be started in gear. What they did was to install a relay in the circuit and have the ground side of the coil wired to the clutch switch. By doing this the clutch pedal would have to be depressed in order to start the vehicle, thus it couldn't be started in gear.
A little info about relays, they can be complicated, but a simple relay like the starter relay consists of two sides, a contact side and a coil side. The contact side consists of a stationary contact and a moveable contact This contact can be either "normally open" n/o or "normally closed" n/c. This refers to the contact position when the relay is sitting on the shelf not wired to anything. The contact side carrys heavy current, it's terminals and wiring are always heavier than the coil side. The coil side is an electro magnet which has a plunger that is attached to the moving contact.
For this starter relay if the clutch is not depressed, if you turn the key to start nothing happens, if you depress the clutch, turn the key to start, current flows through the coil, through the clutch switch to ground. As current flows the plunger is drawn into the coil and the contact closes completing the contact path to the starter and the starter engages.
On the right is the starter relay. Automatics do not have a starter relay, the neutral start switch prevents the vehicle from being started in gear. Automatics and manuals use the same starter, so the starter relay is not installed because starting current is so high that you need a relay, but Toyota uses it in manual vehicles as a safety feature more than anything. Manuals do not have a neutral start switch, so Toyota had to come up with some way that a manual could not be started in gear. What they did was to install a relay in the circuit and have the ground side of the coil wired to the clutch switch. By doing this the clutch pedal would have to be depressed in order to start the vehicle, thus it couldn't be started in gear.
A little info about relays, they can be complicated, but a simple relay like the starter relay consists of two sides, a contact side and a coil side. The contact side consists of a stationary contact and a moveable contact This contact can be either "normally open" n/o or "normally closed" n/c. This refers to the contact position when the relay is sitting on the shelf not wired to anything. The contact side carrys heavy current, it's terminals and wiring are always heavier than the coil side. The coil side is an electro magnet which has a plunger that is attached to the moving contact.
For this starter relay if the clutch is not depressed, if you turn the key to start nothing happens, if you depress the clutch, turn the key to start, current flows through the coil, through the clutch switch to ground. As current flows the plunger is drawn into the coil and the contact closes completing the contact path to the starter and the starter engages.
Oct 16, 2011 | 02:36 PM
#6
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From: S.E. Wisconsin
Excellent information! I've got an R151F transmission and transfer case (originally came with 22RET trucks and 4runners) that I want to use to replace the auto tranny in my '89 4runner (of course I'll need to change to a V6 bellhousing). I had hoped that I could replace the wiring harness with the one from the '88 donor and make it like a factory installation, but I'm happy to do the swap and alter my existing harness. Looking forward to having a 5-speed again.
Last edited by wrenchtech; Oct 16, 2011 at 03:43 PM.
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