cruiser54

Good advice here ^^. Also be sure the hose/pipe to the MAP sensor is not cracked, plugged, melted etc.

Be sure to do the sensor ground test as outlined in the beginning. That can really screw with things it has high resistance. C101 connector cleaning on an 87 is always a good idea.

Just buy the one for the auto and be done with it. Way cheaper and bolts right on and plugs right in. I mentioned it here: RENIX TPS ADJUSTMENT Before attempting to adjust your TPS be sure the throttle body has been recently cleaned. It's especially important that the edges of the throttle butterfly are free of any carbon build-up. IMPORTANT NOTE: Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS . The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. If you see more than 1 ohm of resistance some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. I can provide an instruction sheet for that if needed. MANUAL TRANSMISSION: RENIX manual transmission equipped XJs have a three-wire TPS mounted on the throttle body. This manual transmission vehicle TPS provides data input to the ECU. The manual transmission TPS has three wires in the connector and they're clearly embossed with the letters A,B, and C. Wire "A" is positive. Wire "B" is ground. Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors.. Note the voltage reading--this is your REFERENCE voltage. Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts. Adjust the TPS until you have achieved this percentage. If you can't achieve the correct output voltage replace the TPS and start over. AUTOMATIC TRANSMISSION: RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a flat three- wire connector, same as the manual transmission vehicles have, and it is tested the same as the manual transmission equipped vehicles--FOR ENGINE MANAGEMENT RELATED ISSUES. However, the automatic TPS also has a square four-wire connector clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your REFERENCE voltage. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage. If you can't, replace the TPS and start over. So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU. If you have TRANSMISSION issues check the four-wire connector side of the TPS. If you have ENGINE issues check the three-wire connector side of the TPS. For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced. Revised 11-28-2011

LOL

I am not trying to discourage anyone Just to help with information... It matters not to me if you or anyone else has added a relay harness because you feel you needed it or you think you saw a difference... But I do not like when someone runs out and adds something to thier truck just because some guy on the internet said so... It is just a matter of the proof and your only telling me "cuz I did it and I saw a difference and go look at all the internet sites that say you should" is great for you but it is NOT A Proof... Where as I am sating to that same person test your truck to so if you need it... OH and I Have metered my Truck the last time I was involved in a discussion about H4 conversion here on CC and the voltage loss was so minimal I did not even write it down for future reference so I have done my due diligence and just think others should do the same before spending hard erned money which Is harder to come by for Many american and even some canadians these days... So to anyone who is thinking of such a swap just take a few minutes and test and see if in FACT your Truck has enough of a loss to require spending $30.00 or so on a relay kit that may not even be necessary FOR THEM... Well, I'm not just anybody on the internet so please don't categorize me as such. I have experienced the results I've expressed as have many others. The fact that the headlamps are brighter and the harness costs little more than a headlamp switch, is easier to install and gives peace of mind that a headlight switch failure is not gonna leave you in the dark counts for something. Save your judgements for the guys touting magical spark plugs, throttle body spacers, electric superchargers and such. I really would like to see you install one of these harnesses and SEE the difference. Once again, we have someone who has not done something telling those of us who have, that what we did was fruitless when we know better.

The AMP's are not increasing so you make no sense... The Stock Sealed beam lamp is 55W Low beam = 4.5 AMPS Per lamp = 9 AMPS combined 65W high beam = 5.4 AMPS Per lamp = 10.8 AMPS combined An H4 is still a 55W low beam and a 65W high beam so it is NOT pulling more current unless you run Highe Wattage lamps... I will reiterate: Why are you discouraging people from using the harness on these old, underdesigned systems when the failure rate for plugs and switches is quite common, when you admit you have never used an upgraded harness? Have you ever witnessed first hand the improvement in lighting from stock bulbs with the harness alone? I have, as have many others. The harness was underengineered for the stock bulbs!!

Finally someone understands what I am talking about Age and abuse will take a toll But does not mean everyone’s jeeps has had the same abuse over the years SO Technically speaking not everyone will or does require a relay harness to combat voltage loss... It was underdesigned when new!! It's not only the voltage loss which has been documented but the resistance in the stock circuit which is amp load. Big difference. Again, I will state that you have never installed a harness but many others of us have and seen the results. Read what has happened to many people's headlight switches and plugs with stock lamps. So, here we are 20 plus years down the road and they add higher amp drawing lights. All of a sudden their headlight switch is hot or the lights are blinking on and off. It's more irresponsible of you to discourage people from upgrading the harness having never used one that it is for those of us who have used the product to recommend it.

Well said and I absolutely agree.

This Means Nothing... I have rebuild dozens of Jeeps and repaired 1000's of them Do an actual Voltage reading or get a light meter and record the lumen ouput numbers otherwise it is purely your guess rather then an actual improvement but once again I will sate that if someone thinks they need it do it... I am only giving the information so Every Jeep will differ due to previous proplems or what ever the years may have done to your wiring but the fact is if there is NO voltage loss then there will be NO improvement in a relay harness... Read some of the other forums about this. They will provide the voltage numbers. It is a fact regardless of whether you've experienced it or not. I have. I know it's true. Side by side comparisons. I personally don't care if your headlamp switch/plug melts down and you don't get all the benefit of upgraded lights. I'm just trying to help others out and saving them some aggravation. Why are you making such a big deal out of this? Why in the hell did they come out with these harnesses if there was no market for them?

How about having installed 3 of them, 2 with stock lamps, and one with 90/100 Autopals. The eautoworks harness is fine.

Have you ever just added the harness to a stock Jeep and seen the improvement like myself and others have? It's a known fact that the stock headlamp switches and connectors fail on these rigs with stock lamps. Why tempt fate and have reduced headlamp output by not upgrading the harness? Sorry never... I do not agree that it is a FACT... Yes stock harness's and connectors can fail maybe in some area`s more then others as different parts of the world have different faults... I do not believe that it will increase light output with just the harness the Voltage loss to the headlights thru the factory switch is not enough to weaken the lights... Factory wiring is rated 20 AMPS per Light output (both low Beams or Both High beams) 84-96 Stock Low Beam 55W is 4.5amps 9amps with both lights Stock High Beam 65W is 5.4amps 10.8 with both lights... The H4 conversion using STOCK WATTAGE lamps is not going to pull anymore power then a stock sealed beam lamp but it does give off a better light because of it`s design... I have yet to see any number from anyone debating that a relay harness is needed and showing proper proof... Like other wiring debates On CC I have never said it is a bad idea to use a relay harness because I believe if you think you need it then use it but I will say again that it is NOT mandatory... Every Jeep is different due to unforseen repairs and damages so I would suggest taking a voltage reading at the headlight harness to measure what your actually getting to know if in fact you have a large enough voltage loss at the connector to worry about it... As for where to get the Relay harness I can not say for sure, I get them from my HID Supplier in CHINA and have a few in stock but have yet to need to use one... Good luck with which ever you decide to do... It's obvious you have not done just a harness on a Jeep then.

Year? TCU controls shifting, not the ECU regardless.

Have you ever just added the harness to a stock Jeep and seen the improvement like myself and others have? It's a known fact that the stock headlamp switches and connectors fail on these rigs with stock lamps. Why tempt fate and have reduced headlamp output by not upgrading the harness? Anybody have a known source to buy a harness? I've seen a few out there but am not crazy about buying through a place that is unknown or I've never heard of. http://www.eautoworks.com/Putco-H4--900 ... D7540.aspx

I have no idea why you can't find it or don't remember it. I certainly don't have it -- I never worked at a dealership. I saw it when I had the job done, but that was 22 years ago. It was NOT a factory TSB. Perhaps a dealership service manager sold you the repair? Many/most TSBs were covered under warranty and were not required to be paid for by the vehicle owner within the vehicle's warranty period..

Yes, that's it. There are other ways to do it if the parts are no longer available. Have you ever tested your CPS output?

Sorry, but that's incorrect. It wasn't a recall, but there WAS a TSB to cut out the C101 and splice all the wires. It came out in late '89 or '90. The difference between a recall and a TSB, of course, is that the customer gets raped for the TSBs. I had it done on my '88 Cherokee, and it resulted in NONE of the improvements the service manager told me it would generate. So on the Comanches I leave the C101 intact. This is different from the CPS bypass. That was a separate harness that got run through a new hole in the firewall, directly from the CPS connector into the ECU. Then why can't I find it in my factory TSB manuals out in the garage and why don't I remember it? Please provide the TSB for us to see.

Have you ever just added the harness to a stock Jeep and seen the improvement like myself and others have? It's a known fact that the stock headlamp switches and connectors fail on these rigs with stock lamps. Why tempt fate and have reduced headlamp output by not upgrading the harness?

J is 88. There was no dealer mod to remove the C101 connector. I was Service Manager and Shop Foreman at a Jeep dealer from 1981 til 1992. The only thing the factory suggested was cleaning the C101 and I'm pretty sure that was't in a bulletin, but a verbal suggest from the guys at JeepTech. There was a wiring mod to bypass the C101 with the CPS wires and have them go directly to the ECU.

Since it's an 87, expect longer crank times. But, the C101 connector has the CPS wiring running through it and that can reduce the signal the eCU sees, resulting in longer crank times. You should do this regardless as almost all sensor signals run through that crappy connector. BTW, did you adjust your new TPS? Renix Jeep C101 Connector Refreshing The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before. Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101. The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time. Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth. If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together. Revised 11-29-2011

Since it's an 87, expect longer crank times. But, the C101 connector has the CPS wiring running through it and that can reduce the signal the eCU sees, resulting in longer crank times. You should do this regardless as almost all sensor signals run through that crappy connector. Renix Jeep C101 Connector Refreshing The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before. Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101. The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time. Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth. If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together. Revised 11-29-2011

The upgrade harness is mandatory. The headlight switches in these Jeeps melts down with stock lamps. The real bonus is the harness is super easy to install and even if used alone will make your stock headlights about 30% brighter while taking the high amp load off the headlamp switch. http://www.eautoworks.com/Putco-H4--900 ... D7540.aspx Cruiser’s Headlight Upgrade Harness Instructions Absolutely plug and play. Remove grille and headlamp bulbs. I fed my harnesses from the passenger side starting between the battery and the back of the headlamp housing, over to the driver side. Plug the driver side bulb into the new harness. Attach the new harness's ground wire under one of the small bolts on the radiator support after scraping the paint off under it. Attach the harness to the existing harness behind the grille working toward the passenger side. . Plug the new harness plug into passenger headlamp. Plug original headlamp plug into receptacle on new harness. Attach the ground for the passenger side just like you did the driver side under a radiator support bolt. Attach relays with provided bracket on the passenger side inner fender. Connect power wires to battery.

I think you'd be fine with one from a similarly equipped Cherokee.

Let's see a pic of it. What's the 10th digit in your VIN? If it never had the C101, I doubt the bracket would be there. Never seen that.

No need to. Just bypass the original HCV. Heat is controlled by the blend air door, not the HCV anyway. I live in Arizona and have bypassed many HCVs with no ill effects. Real cold AC.

NSS? Am I missing something or should I believe his info in the original post that he has a manual trans?