3G Alternator/Tripminder

[Steve'87]

Hello
I'm sure these have been asked a dozen times before, so I apologize, but I can't find what I'm looking for except for bits and pieces here and there.

1. Why do I want to upgrade to a 3G Alternator? I can find the how to do it, and where to get one, but not why I should. The reason I ask is the one in the car works fine AND I have an almost brand new spare one in the CV. (2G of course)

2. Tripminder. I want to take the Tripminder out of my '89 CV parts car and put it into my '87 GM. The GM just has the digital clock, and the wiring is different. Is there a trick I should know about, or a plug somewhere under the dash? I've seen some info on the older CFI cars, but not on the EFI cars. Is there a pigtail I can swap out, or do I have to splice wires? I would like to find out before I have to tear the dashboard apart on the CV to try and find out. Wouldn't be so bad except for the bees.

If there's already a thread on either one of these, please point me in that direction. Any help is much appreciated.

[87gtVIC]

I can help you with the alternator.

Sometimes when a heavy load is applied on the alternator such as having the blower on, lights on, wipers going, rear defrost etc your harness (the rectangular three plug one with two large cables and one skinner one) can actually melt and cause a fire. This has happened to a couple of members here and this is a common problem across all vehicles utilizing the 2g alternator. Simply put the alt is underpowered for the demands these cars give it, and the entire charge set up on them is just bad, through the utilization of spade connectors.

[FatNasty]

As for the alternator, its best gain is that it will put out a lot more amps. If you want to run an electric fan, big stereo system, or a lot of electronics, etc it is good. On a stock car, 2g isn't bad or anything power wise, but there is a bit of a fire hazard as described above with the harness. Think there was a better one introduced later. 3G upgrades are cheap, and less wiring involved. Used 3g's can be had cheap, there are 2 at pull n' save in spokane right now in 3.0 taurus's for like $13.

As for the tripminder, the one from your 89 will work in your 87, but 2 wires will need to be either added, tapped, or extended. There isn't an actual harness that will plug strait into the tripminder in you 87 so take the 89's wires with you. There is a fuel flow wire that the tripminder requires that will either be wired under the dash in your 87, (not likely), in an empty single wire harness under the hood near the main engine wiring harness plug, or nowhere at all. I think i remember the actual harness from '89's being different from other harnesses in some small stupid way.

Seems like a lot have the wire dangling near the main wire harness plug, under the hood. If it isn't there, the wire probably needs added by way of adding a pin to the ecm plug in the #34 slot. some info on it here, half way down the page. http://www.grandmarq.net/vb/showthread.php?t=6506

The second wire that needs tapped is the vehicle speed sensor wire, which will be a dark green wire with a white stripe. This will be under the dash, in the general vicinity of the brake pedal (see pic #4 in the previous link). Tap this wire, and run it to the tripminder, and along with the fuel flow wire, and it will be fully operational. The other 4 wires are the same as the regular digital clocks, will just need spliced in.

If you run into serious problems, you can just visit me, i've done it enough times. They are my favorite accessory to add by now i think.

[gadget73]

If you can get a complete tripminder harness from an 87, do that because it makes installing it much more easier. The plugs are in a different spot on the 89. You can modify it easy enough, but having the exact correct harness makes installation easier.

[86VickyLX]

If you can get a complete tripminder harness from an 87, do that because it makes installing it much more easier. The plugs are in a different spot on the 89. You can modify it easy enough, but having the exact correct harness makes installation easier.

This, it has a plug to splice right into the cruise control wiring harness so you can add the tripminder with ease.

[Steve'87]

I can help you with the alternator.

Sometimes when a heavy load is applied on the alternator such as having the blower on, lights on, wipers going, rear defrost etc your harness (the rectangular three plug one with two large cables and one skinner one) can actually melt and cause a fire. This has happened to a couple of members here and this is a common problem across all vehicles utilizing the 2g alternator. Simply put the alt is underpowered for the demands these cars give it, and the entire charge set up on them is just bad, through the utilization of spade connectors.

Ah yes, that makes sense and brings back a memory of having to replace the alternator electrical plug on the CV because it melted down. Until I get ahold of a 3G, couldn't I replace the charge wire with a heavier duty wire with a fuse or circuit breaker?

As for the alternator, its best gain is that it will put out a lot more amps. If you want to run an electric fan, big stereo system, or a lot of electronics, etc it is good. On a stock car, 2g isn't bad or anything power wise, but there is a bit of a fire hazard as described above with the harness. Think there was a better one introduced later. 3G upgrades are cheap, and less wiring involved. Used 3g's can be had cheap, there are 2 at pull n' save in spokane right now in 3.0 taurus's for like $13.

Big stereo, yup, killed a few alternators with that thing. Also have 2-way radio equipment. I love Pull and Save but it's 120 miles away. And the darn local yards want like-new prices for like-junk parts.

As for the tripminder, the one from your 89 will work in your 87, but 2 wires will need to be either added, tapped, or extended. There isn't an actual harness that will plug strait into the tripminder in you 87 so take the 89's wires with you. There is a fuel flow wire that the tripminder requires that will either be wired under the dash in your 87, (not likely), in an empty single wire harness under the hood near the main engine wiring harness plug, or nowhere at all. I think i remember the actual harness from '89's being different from other harnesses in some small stupid way.

Seems like a lot have the wire dangling near the main wire harness plug, under the hood. If it isn't there, the wire probably needs added by way of adding a pin to the ecm plug in the #34 slot. some info on it here, half way down the page. http://www.grandmarq.net/vb/showthread.php?t=6506

The second wire that needs tapped is the vehicle speed sensor wire, which will be a dark green wire with a white stripe. This will be under the dash, in the general vicinity of the brake pedal (see pic #4 in the previous link). Tap this wire, and run it to the tripminder, and along with the fuel flow wire, and it will be fully operational. The other 4 wires are the same as the regular digital clocks, will just need spliced in.

If you run into serious problems, you can just visit me, i've done it enough times. They are my favorite accessory to add by now i think.

Ok, I have a dark green wire w/white stripe near the brake pedal. It has a black wire for a companion, it it seems to dead end. Under the hood I have a single wire dangling right next to the ecm harness/plug. It's a light blue wire with purple stripe, could that be the one?

If you can get a complete tripminder harness from an 87, do that because it makes installing it much more easier. The plugs are in a different spot on the 89. You can modify it easy enough, but having the exact correct harness makes installation easier.

I wish, but all I have to work with is the '89 for parts. I'll just splice the wire in.

[87gtVIC]

I do not think there is a way to bypass the charge posts on the 2g. They are tucked in the alternator with only that plug contacting them. You could only add thicker wire to the existing wires but in the end the plug connections remain the same. No idea about the circuit breaker install with original wiring.

[Steve'87]

I do not think there is a way to bypass the charge posts on the 2g. They are tucked in the alternator with only that plug contacting them. You could only add thicker wire to the existing wires but in the end the plug connections remain the same. No idea about the circuit breaker install with original wiring.

Yeah, I just went out and looked, no way to get away from that plug, so I wouldn't gain much. And I noticed the harness is slightly different from '87 - '89. I'll just have to get my hands on a 3G as soon as I can.

[Steve'87]

Crap!!! Found a thread that would probably answer all my questions about the tripminder, but all the pictures are X'd.

[yucatecd]

It's an odd feeling when the alternator light goes on and the electrics act up and it gets odder when you pull over and open the hood and your engine's on fire. Not recommended for those traveling w/o a fire extinguisher.

Donald McCaig

[FatNasty]

Big stereo, yup, killed a few alternators with that thing. Also have 2-way radio equipment. I love Pull and Save but it's 120 miles away. And the darn local yards want like-new prices for like-junk parts.



Ok, I have a dark green wire w/white stripe near the brake pedal. It has a black wire for a companion, it it seems to dead end. Under the hood I have a single wire dangling right next to the ecm harness/plug. It's a light blue wire with purple stripe, could that be the one?

Yeah, i suppose the drive from there is a bit much. Got to pick one up when you're already going to spokane for something.

That wire you found next to the ecm harness should be the one, that will make things a lot easier. splice in some wiring and you're set.

[MattsLincoln]

check my thread on cruise control wiring diagram. That will help you locate the speed sensor wire.

[MattsLincoln]

here my thread to help you locate the speed sensor wire on your car. Just scroll down to 1987 Ford/Mercury.

http://www.grandmarq.net/vb/showthread.php?t=39065

[GM_Guy]

I do not think there is a way to bypass the charge posts on the 2g

Actually, there is an aftermarket regulator block for the 2G that converts it to a post.
WAI (transpo) FR191

Alex.

[GM_Guy]

See attached...