Repairing my 944 tail lights – Tail light fuse late 944
After my last trip to AMP for track night, I ended up having to drive my race car home due to a tow vehicle failure. Halfway home, I stopped to eat and noticed the tail lights were not working. However, I had two very nice tag lights so I elected to make it home anyway.
Last night I decided to dig into why the tail lights were not working. I expected to find a loose wire or failed bulb. Neither of these was the case.
I then decide to check the fuses and after searching the inside of the fuse box and several internet searches, I could not find a listing for the tail light fuse. I read through a couple of forums and still no mention of a tail light fuse.
So next I printed out the wiring diagrams. These are hard for me to follow but even more so in that, the individual bulb functions are not listed on the diagram. It shows all the bulbs in the tail light housing but not what each one does.
So I pulled the tail lamp assemblies apart and traced the wires from the non-functioning bulbs to the connector and determined the wire color on the harness side fo the connector. That is when I noticed that a previous owner had redone the wiring so that the left side tail light was jumpered to the right side taillight. I found that odd but continued.
I finally figured out that the tail light bulbs also power the side markers. I don’t have side markers on the race car but I do still have the plugs dangling from the tail light housings. I remembered seeing a side marker fuse listed when I was researching.
So fuse 40 and 41 are listed for the side markers. Sure enough, both these fuses were blown. I tried replacing fuse 40 and it would instantly pop indicating a dead short. Fuse 41 seem loose.
After tracing the wiring diagram again, I figured out why the previous owner had jumpered the two tail lights together. The left side marker circuit has a dead short. So he powered the left side off the right side.
I then replaced the fuse for the right side marker circuit and wiggled it around to get it to seat properly. After some wiggling of connectors in the rear of the car again had tail lights on both sides.
I will later go back and see if I can locate the short in the left side circuit. I expect this is why my left front marker has never worked.
The adventure began with the seven hour tow to Virginia. VIR is located like most race tracks in the middle of nowhere. But VIR is different in that you can’t get there from here. You have to go somewhere else first them go to VIR. If you are in Virginia there is no road to take to the track that does not go through North Carolina on the way.
I looked at several options before choosing the fastest route according to Google maps. What I failed to notice in my route planning was the 9 mile long 9.5% down grade after getting off the interstate.
Normally this would not have been too bad however just as I was stopping for fuel earlier I had noticed a warning on my brake controller. There was a short somewhere. When I got on the twisty section I had made a quick attempt at diagnosis and found that if I switched off the front brakes, the fault would clear and I had at least one axle of trailer brakes. Normally this is plenty but for the long steep down hill run not quite so much.
I made my way carefully down the hill alternating between braking and cooling and lots of compression braking. I was very happy to get to the bottom after about twenty minutes of pucker.
Tom met up with me in Danville to get fuel. But we decided it was too far to haul the fuel to the cabin and back so we fueled only the race car for the Holiday Laps session on Friday. While fueling we noticed there was still a lot of heat coming off the trailer tires.
Evan booked us a nice cabin on the lake close to the track since there are no hotels nearby. The narrow driveway looked a lot like a Jeep trail but I found a place to park the trailer only a short walk from the cabin. It was dark and cold so I grabbed my gear and hopped in Tom’s car.
The next morning at dawn, I went to look at what it was going to take to get turned around. As I was scouting the path out, I noticed something odd about the trailer.
The right front trailer wheel hub and brake assembly was missing. In its place were a couple of worn bearing races. I have no idea when it left. I decided there was nothing left to do but drive on three wheels to the track and deal with it later.
I had no idea how poplar the Holiday laps program is at VIR. My GPS said I was still a mile from the gate when I stopped at the back of the line. And I thought we had gotten there early. Anyway, we paid our entry and then found a place to park where we could unload the car and work on the trailer.
We sent Evan out first and he got in a few paced laps. However when he came back the car was making a noise and the dash warning light was on. Popping the hood showed the alternator mounting bolt had backed out letting the belt slip. Unfortunately access to the adjuster requires removing our brake cooling duct. Not a bad job on the lift but a little awkward on jack stands in the parking lot.
With her belt back tight we sent Tom out to get in line. The line was now about 500 cars long. Evan and I realized he was going to be in line a while so we took Tom’s car to tractor supply and found a hub and a wheel and tire.
I also bought a chisel thinking I would hit the race and it would break off. The chisel was not near as hard as the bearing race and soon I just had a flat metal bar. Evan was able to find a grinder and cut off wheel with one of the better equipped teams. He also found a place to plug it in near where Chumpcar had tech set up.
The cut off wheel made short work of the bearing races. I had the new hub and wheel on while Tom was still waiting in line. He decided to let me take is stint so I waited a bit more and then took some paced laps of the full course. It is a very nice track with interesting elevation changes and different types of turns. However compared to COTA it is a bit narrow. All the run off areas are grass.
Tom got to wait in line again before he took his stint near the end of the day. We then bolted the brake ducts back in place and used the car to scoop a well-placed paddock spot before the trailers were allowed in.
Afterwards we took the trailer out to get 110 gallons of fuel. But in the excitement, we forgot to buy a couple of gallon jugs of water like we normally do.
We woke to a very cold morning on Saturday. We normally like to have our pits set up the night before but the track did not allow this. In fact it was almost time for the driver’s meeting before they allowed us in. We felt a bit rushed getting everything set up and somewhat organized.
Evan took the first stint and turned some very respectable times. The car seemed to be running well and handling well once the new Hankook tires warmed up a bit.
I took over for the second stint. I went slower being intimidated by the number of cars on the narrow track. I eventually got in the groove and had a good run. The only glitch being my radio microphone was not working. I could hear but not talk.
We made a quick driver swap to Tom. However in just a few laps he was back in with the engine hot. This is when I realized we never bought water. I used water bottles from the cooler while Evan went in search of more water. I was able to burp the system and get Tom going again. Evan ended up buying a fuel jug from the pro shop to hold water for future stops.
We put Evan in again in the afternoon. He was really mixing it up and turning fast laps when he got tagged by Neon in a critical spot. The impact sent him off into the grass and then hard into the tire wall. He then spun around and impacted the guard rail. In car video shows the violence of the crash. He was able to move slightly but had to get assistance back to the pit. The car still ran but would not move.
I quickly diagnosed the problem as a broken half shaft. And I had bought a spare just in case.
I crawled under the car and began removing the bolts. Thankfully none of them stripped out. We might have made it back on track on Saturday but the new in the box shaft had a problem that required it to be disassembled and reassembled to get the balls in place.
I had Phil the chief inspector come take a look at the car and give his blessing before we took it back out on track. He also took a look at our in car video to see who had hit Evan to push him off. We had to tape up the broken rear hatch and straighten the frame a bit to get it to latch.
Amanda said it felt like we were back in Harlan as we all worked together to get the car ready to race on Sunday. The other 944 teams stopped by to offer support and offered to loan us parts or tools as needed.
On Sunday morning I took the car out to rejoin the race. I was tentative at first but I picked up sped as I realized the car handled just fine. The tape on the rear window blocked my view a bit and the missing door mirror caused more problems. But I was able to run my full stint and turn the car over to Tom.
I did take the car to the paddock to torque the half shaft bolts. It was a good thing I did too since some had not seated well in the cold the night before. However in the process I suffered my least favorite moment of the weekend. Somehow I got my pinky finger pinched between the wrench and the wheel as someone outside the car tried to move the wheel so I could access the next set of bolts. The worst part was having to bring it back across the pinch point to get my hand out.
Jenny cleaned my injury and bandaged me up. Tom took over the car and headed back out on track. He was able to improve slightly on his previous lap times.
We made a quick swap to Evan. He was turning really good laps when he called saying he had alternator issues. Remembering the Friday experience, we checked the belt tension but it was fine this time. We took it to the paddock for further diagnosis.
My voltmeter was showing 14 volts at the battery but the dash meter was showing ten volts. Since the car was running fine I sent him back out assuming it was a wring glitch.
I took over for my last stint of the weekend. I was finally getting comfortable with the close proximity of other cars and learning my way around the track. Then I noticed a stumble in the car in a few corners. I saw the voltage was steadily dropping on the digital meter in the car.
I ran as long as I could but the stumble got worse and the engine began to cut out at times. I put it behind the wall and checked the system again. I still could not figure out why the battery read a higher voltage than the rest of the car. We reluctantly made the call to load it on the trailer rather than changing the alternator. I discovered after I got home that the battery was low in my voltmeter which made it give incorrect readings.
Overall it was quite an adventure. I was reminded of Neal’s comment: “racin’ is ‘spensive.” I do kinda wish I had changed the alternator and taken the car back out for what remained of the race. Just to say we didn’t quit. But we did gain a lot of new friends and respect among our fellow racers that we were able to get the car back on the track during the overnight stop. It was a long drive home in the rain but I made it home safely taking a different route that avoided the 9 mile 9.5% grade.
We ended up in 42nd place. I think we turned more laps than two of the other 944s. Visceral Racing’s 944 ended up in 38th place. All the 944s had issues both days.
Our plan is to have the car ready to race by the February event at Road Atlanta.
We have been rebuilding our first ChumpCar. It is a 1975 Toyota Celica. The car belongs to our team mechanic. He has found he has cancer so we have all pitched in to build it for him to race at Daytona.
When we got the freshly rebuilt engine in the car, we found it would not make any oil pressure. We tried priming the oil pump and every other thing we could think of. It simply would not build oil pressure.
After studying the oil flow diagrams, I noticed there was a galley plug in the bottom of the engine. I had noticed that the front and rear plugs were pulled by the machine shop. Of course the builder had replaced those. I called him and asked about the lower one. No one could remember putting that one back.
I really did not want to pull the engine back out just to check to see if the plug was missing.
My first check was to run a wire down the passage from the oil filter to the bottom of the engine on a spare block. I then did the same on the engine in the car. The one in the car would go an extra inch or so.
My next step was to see if I could get the oil pan off with the engine still in the car. There is very little clearance between the oil pan and the cross member.
I began by seeing if I could access all the bolts. I got most by using a short 12mm socket on a wobble extension.
The two right above the cross member I got using a wobble socket.
I had to remove the two engine to transmission braces to get to the back four bolts.
Next, I disconnected the steering rod from the pitman arm and the idler allowing it to drop. I then removed the four bolts holding the motor mounts in place.
I set a jack under the front pulley and began to slowly lift the engine. I had to raise it a couple of inches to get the pan to clear the oil pick up.
With the pan off I could easily see that the lower galley plug was missing.
I pulled the one from the spare block and transferred it to the engine in the car. Then I had to figure out how to get the pan and gasket back on.
It would have been easier to just glue the gasket to the pan but I used a trick I have learned on the Jeeps. I threaded long wire ties through the pan holes into the gasket. I put one on each of the four sides. I then lifted the pan into place and put on the two nuts for the two studs. I then carefully slid the wire ties out while inserting bolts into the holes that were opened up.
Once the pan bolts were snug, I set the engine back in place and reattached the motor mounts. I then reinstalled the engine to transmission braces and the steering rod.
After refilling with oil, I tentatively turned the engine over. I was very happy to see the oil pressure gauge start to move. We were back on schedule with our Daytona Build.
The car ran flawlessly all day. We got a couple of new battle scars but still drove it on the trailer after the checker flag.
Our pits stops went well and even though our laps times were not as fast as we would have liked, we finished 32nd out of 110 cars. We found that there car can go over three hours on fuel so we skipped fuel on two of our driver swap pit stops. That gained us a lap or two. We completed 338 laps this year in the 14 hour race.
In order to improve the aerodynamics of our Porsche 944 ChumpCar racer, we decided to add a Lexan hatch. The ChumpCar rules require all glass other than the windshield to be removed. For our first race, we removed the glass and ran just the hatch frame. After looking at the other 944s racing against us we decided to add a Lexan hatch like they had.
We ordered the material from Five Star Race Car bodies on the advice of one of the other teams. This is the same material sold by Porsche specialty shops for about $100 less. The material surprisingly comes rolled up in a small box so shipping costs were reasonable.
Since we already had the glass out of the hatch we were able to start right away. Removing the glass from the hatch frame is challenging and requires a lot of patience. I have seen youtube videos of people breaking theirs out but they still had to deal with all the little pieces in the channels. I used an oscillating tool to cut the bonding material and carefully removed the glass. I had a heat gun for some places but mostly where the bonding material was cut, the glass lifted out.
We began by laying out the screw holes making sure there was no more than ten inches between holes. We paid extra to have the material cut to the size of the original rear glass. We may have been better off buying the oversized version as ours was just a little smaller than we would have liked.
We marked and drilled all the holes in the perimeter of the frame. Then we set the Leaxan in the upper groove and pressed it into place. We then carefully drilled through each hole into the Lexan. I found that if the bit ran too fast, the material would melt rather than drill and would refill the holes when the drill bit was removed. After a few holes I had the technique down. The biggest trouble we had was finding the right place to drill the holes. The best spacing away fort eh edge of the window put us in a ridge on the inside of the frame. This caused some of the holes to be angled which gave us trouble later.
We used a hand brace and a large drill bit to cut the counter sinks. We used the screws provided in the mounting kit from Five Star. The kit seemed a good value as it came with the right screws, locking nuts and a drill bit.
Due to the way the nuts hit the back of the frame, the ridge caused the nuts to not seat right. We ended up using a cutting tool to notch the frame at each of the screw holes so the nuts could sit flat. This also allowed us to use the shorter screws in the kit allowing the hatch to fit better when back on the car. Notching the frame took away some strength but once careful handling allowed us to get the Lexan mounted without it bending. Once the Lexan was in place the rigidity returned.
We added the two required one inch wide aluminum strips over the hatch and bolted them top and bottom. We then put all the rubber trim pieces back on the hatch to cover the holes and retain the look and function of the original spoiler.
The new hatch is very light weight and looks nice. We hope the performance improvement will be worth the cost and two weekends of work required to make the swap.